Wild Mammals of Wisconsin (Faunistica)

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THE WILD MAMMALS OF WISCONSIN Charles A. Long

INTRODUCTION

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This page intentionally left blank

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THE WILD MAMMALS OF WISCONSIN

The Wild Mammals of Wisconsin Charles A. Long

SOFIA–MOSCOW 2008 INTRODUCTION

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THE WILD MAMMALS OF WISCONSIN Charles A. Long Professor Emeritus at the University of Wisconsin – Stevens Point, Stevens Point, Wisconsin AN

IM AL

IA

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PRO TIS TA

E TA AN PL

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Publication No. 56 Museum of Natural History University of Wisconsin-Stevens Point Reports on the Fauna and Flora of Wisconsin* *Also published as Reports of the Museum, and Reports on the Fauna and Flora. Publication Costs and the Museum’s Distribution of this Book were funded by Harold Roberts – Stevens Point, Wisconsin

First published 2008 ISBN 978-954-642-313-9 (paperback) ISBN 978-954-642-303-0 (hardback) Pensoft Series Faunistica No 68 ISSN 1312-0174

© PENSOFT Publishers All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the copyright owner.

Pensoft Publishers Geo Milev Str. 13a, Sofia 1111, Bulgaria Fax: +359-2-870-42-82 [email protected] www.pensoft.net

Printed in Bulgaria, January 2008

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CONTENTS

PREFACE

7

ACKNOWLEDGMENTS INTRODUCTION

9

11

THE WILD MAMMAL FAUNA IMPORTANCE

OF

MAMMALS

PLAN OF THIS BOOK SCOPE

AND

11 13

17

PLAN

17

FREE EXPRESSION

IN

PRESERVATION

OF

SPECIMEN COLLECTIONS

COUNTIES

TYPE LOCALITIES

22

EARLY MAMMALOGY AND NOW

25

AND

TAXONOMY

21 AND

HABITATS

ENVIRONMENTS AND ECOLOGY OF MAMMALS GENERAL ECOLOGY

OF

WISCONSIN MAMMALS

FORMER GLACIATIONS CLIMATE

31

31

32

33

PHYSIOGRAPHY SOILS

21

34

36

COMMUNITIES MICROHABITATS

38 41

ECOLOGICAL SUCCESSION ZOOGEOGRAPHY

AND

LAND USE

43

47

PREHISTORIC MAMMALS

55

REINTRODUCED AND EXTIRPATED MAMMALS OF WISCONSIN WITH HYPOTHETICAL LIST OF SPECIES POSSIBLY IN WISCONSIN CHECK-LIST OF WISCONSIN’S WILD MAMMALS

59 64

KEY TO ORDERS AND FAMILIES OF WISCONSIN MAMMALS

66

TAXONOMIC ACCOUNTS OF MAMMALS OF WISCONSIN ARRANGED IN ORDERS, FAMILIES, GENERA, SPECIES AND RACES OPOSSUM (ORDER MARSUPIALIA)

68

68 INTRODUCTION

5

INSECTIVORES (ORDER INSECTIVORA) MOLES (TALPIDAE)

75

76

SHREWS (SORICIDAE)

84

BATS (ORDER CHIROPTERA)

108

HARES AND RABBIT (ORDER LAGOMORPHA) RODENTS (ORDER RODENTIA)

143

155

WOODCHUCK, CHIPMUNKS, GROUND, RED, GRAY, FOX

AND

FLYING SQUIRRELS (SCIURIDAE)

156

NORTH AMERICAN BEAVER (CASTORIDAE) POCKET GOPHER (GEOMYIDAE)

220

229

MURID MICE AND RATS (MURIDAE) JUMPING MICE (ZAPODIDAE)

235

304

NORTH AMERICAN PORCUPINE (ERETHIZONTIDAE) CARNIVORES (ORDER CARNIVORA) COYOTE, WOLF,

AND

321

FOXES (CANIDAE)

BLACK BEAR (URSIDAE) RACCOON (PROCYONIDAE)

315

321

351 359

MARTENS, WEASELS, MINK, SKUNKS, RIVER OTTER, NORTH AMERICAN BADGER (MUSTELIDAE) CATS (FELIDAE)

366

427

DEER (ORDER ARTIODACTYLA) 438 WHITETAIL, MOOSE (CERVIDAE) GLOSSARY

439

453

LITERATURE CITED AND BIBLIOGRAPHY

461

APPENDIX A. Longevities of Some Mammals That Occur in Wisconsin APPENDIX B. English and Metric Measurements

529

APPENDIX C. Preparation of the Mammal Study Skin with Label and Skull APPENDIX D. Dental Records

528

530

533

INDEX TO SCIENTIFIC AND VERNACULAR NAMES OF WILD MAMMALS OF WISCONSIN

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539


PREFACE The mammals of Wisconsin were studied by my friend, the late Dr. Hartley H. T. Jackson, who published his findings in 1961. In the past 45 years the fauna has changed. Some mammals have vanished, others have established new populations here, and the names of the mammals, both scientific and popular, have undergone many changes. In Jackson’s day science was more observational and descriptive than today. Although superficially they may seem similar, his book is different from this one. Jackson began his work in the early part of this century. In his later years he carefully studied the status of Wisconsin mammals from their relations with pioneers through the decades of exploitation by hunters, and heavy land use by settlers, farmers and townspeople. His work focused on the turn of the century to about 45 years ago. This work reviews Wisconsin mammalogy in light of many new scientific findings, and at the turn of another new century, indeed, at the beginning of a new millennium. In the presentation of natural history, with particular emphasis on the sign of mammals observed in the field, on material of historical and popular nature, and on the clear descriptions of specimens and species, Jackson has no peer except perhaps Ernest Thompson Seton. The bibliography in Jackson’s work (1961) is a supreme Wisconsin compilation up to that time. However, there is no mention of many modern concepts, even echolocation in the bats; there is too great a dependency on temperature zones to explain the ecological and geographical distribution of Wisconsin mammals; and there is not a word about the strongest rationale for modern taxonomy, including evolution, fossil record, and speciation of taxonomic categories. Nevertheless, Jackson’s work is a “tough act to follow.” I will repeat a famous saying, “cosa ben fatta e` fatta due volte” [anything worth doing is worth doing it twice]. This book is written to serve three groups of readers. First, serious professional mam-

malogists in Wisconsin, and in many other states and provinces, need an updated source of information about Wisconsin’s mammals. For this group, the taxonomy was updated, and the new collection of mammals at Stevens Point’s Museum of Natural History was studied and processed. The information obtained here and from other studies provides a source book for mammalogical investigations. Second, there are many nature lovers in Wisconsin who have curiosity about animals. For this group, nature and wildlife provide the joie de vivre. Even many children have a bent in this direction, and this curiosity and passion should be encouraged with source books about nature. I was one such child myself. My fifth grade teacher, Velma Kane, gave me a fine book by Frank M. Chapman that set my path. I make no apology for anecdotal and even poetic commentary, for those appreciative of that are a welcome audience. Hopefully this book will serve the nature lover in pursuit of enjoyment, enthusiastically finding a “joy for life”. Third, professional and amateur conservationists need factual information on the status of Wisconsin wildlife. They must convince politicians and bureaucrats of ways and needs to save wildlife in Wisconsin. Human population growth and expanding land use have reduced and altered wildlife habitats throughout the State. In my travels on this continent and abroad I have always been impressed with the natural beauty of our own Wisconsin. There is much wonder and aesthetic pleasure here at home, in Wisconsin, but how little of it there is to go around. How easy it seems for people to convert a scenic and natural place into an unnatural commercial development, unsuitable for wild creatures. Some sportsmen serve both as nature protectors and conservationists. Aldo Leopold was one, and my friend Fran Hamerstrom was another. Some teachers fit into this category, as do those people who keep informed on environment while enjoying nature, apart from aesthetic enjoyment. PREFACE

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Hopefully they will in future continue to conserve important habitats for wildlife, because that will be needed. *** Anyone curious enough to put forth effort in nature study will find that nature takes a person into her confidence, and life will be made richer for such effort. This book contains interesting and useful information on the wild mammals of Wisconsin. I hope that it may stimulate some important study and conservation of this legacy and resource. Though few people know about it, the scriptures of the Old Testament and the Torah provide those of us interested with a wise lesson in conservation. God says we “strangers” must provide “redemption of the land” (Leviticus 25:24).

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HOW TO USE THIS BOOK There are special features that help the reader locate particular topics of interest. * The Table of Contents at the beginning of the book. * The Index for species names at the end of the book. * A Glossary of mammalogy terms near the end of the book. * A Check-list of the species accounts of the wild mammals of Wisconsin, immediately preceding the accounts, which comprise most of the text. * The Plan of the Book explaining the format and rationale for the way the explanation is presented.

ACKNOWLEDGMENTS I am sincerely grateful to my family for the support they provided for this study. My wife Claudine and two sons Alan and John, his son Tyler, have traveled to all corners of Wisconsin, to all four borders, even into Upper Michigan, Minnesota, and Ontario. The family put up with me, while I taught heavy course loads and kept at this project for 40 years in Wisconsin. Secondly, I wish to acknowledge the enduring, patient, and competent editorial work on this book by Professor Lowell L. Getz, Department of Ecology, Ethology, and Evolution, University of Illinois, Urbana, Illinois. He was outstanding and necessary. The Wisconsin Department of Natural Resources (Bureau of Endangered Resources) provided one grant, jointly with the Stevens Point Bill Cook Chapter, Isaak Walton League and the U.S. Department of the Interior. This state agency and the United States Fish and Wildlife Service provided me a grant (1979-1981) to study Wisconsin bats. The University Personnel Committee provided several summer grants that paid part of summer salary. It supported my University of Wisconsin Sabbatical, which I spent at St. Olaf College working on fractal geometry and chaos theory (in the same class as my son John). While there, I wrote up about l5 species accounts and made over l00 maps for this project. Paul Humke, Math Department, helped greatly. Faculty who helped in various ways include deceased George Becker (I used his base map for distributions), Philip Bjork, Virgil Thiesfeld, Shelley Jansky, Robert Bell, Frank Bowers, David Hillier, born for computers, Robert Freckmann, Stephen Taft, Vincent Heig, Sol Sepsenwol, gifted and kind, Daniel O.Trainer, Mark Boyce, Stan Szczytko, Christopher Yahnke, Isabelle Girard, and at the Madison campus Frank Iwen and Scott Craven. I am grateful to former teachers from Kansas, especially the late E. Raymond Hall, Robert Wilson, and Horace Hays. Many students helped making up specimens and helping with fieldwork. I cannot list

any without being unfair. Adrian Wydeven, Tom Jessen and others (Wisconsin Department of Natural Resources) helped early in several ways. Thor Purrinton helped me survey Detroit Island. Catherine Ladd (Information Technology) and Teodor Georgiev (Pensoft Publishers) were very helpful. I had the much-appreciated help of two undergraduate students: Nicholee Theiss, and Sarah Miller. Museum curators allowed me to examine specimens or sent them here on loan including John Paradiso, Robert Fisher, the deceased J. Knox Jones, Jr., Robert Baker, the deceased E. Raymond Hall, Michael Carleton, Al Gardner, the deceased Elmer Birney, Frank Iwen, Philip Humphrey, Rollin Baker, Donald Hoffmeister, Scott Craven, the deceased Fred and Fran Hamerstrom, Don E. Wilson, and Wendell Johnson. Photographs were given by the late Roger Barbour, Matt Lovallo, Frank Iwen, Chuck Pils, Al Cornell, D. Shelley, C. Yahnke, Ron Jurawski, R. Johnson, and Scott McDonald. James Spero’s (1978) collection of photos, published by Dover Publications, was useful and appreciated. Sylvia Myhre made the drawings of skulls of moles, shrews and bats. If there are helpers overlooked, please feel appreciated. The U.S. Postal Service permitted the stamps showing mastodon and mammoth, both prehistoric elephants, 1996. Reviewers of various accounts include Getz, who read them all, Scott Craven, Robert Freckmann, Jerry Choate, [the late] Karl Koopman, Wayne H. Davis, who both read the bats, Stephen Taft, Mark Boyce, Jerry Wolff, John Whitaker, Jr., Tim Lawlor, Bruce Kohn, W. E. Berg, K. McCaffery, Joe Merritt, Adrian Wydeven, Tom Howard, L. R. Petersen, and Rebecca Sealfon. I relied on the wolf book by Dick Thiel and a paleontological contribution by R. M. West and J. E. Dallman. Hartley H. T. Jackson, deceased, helped in the beginning years. Wanting of some quality illustration, I gathered some drawings from early and historic sources. Becoming quite interested in ACKNOWLEDGEMENTS

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Raccoon. Artist Roger Tory Peterson. Courtesy Virginia Peterson, her “first choice” for this book. R. T. Peterson and James Fisher 1955, © RTP and J. M. M. Fisher, reprinted by permission of Houghton Mifflin Co. Rights reserved.

the art, I expanded the search. Hoping for a kind of legacy of former mammalogists, not only of quoted observations, I resurrected some of their art, for old published works are becoming rare. Although the artists themselves are not always mentioned, they may be credited in the works. Included are black and white works from Anna B. Comstock, Anna Stryke, and A. MacKinnon, H. H. T. Jackson (artist B.O.M[cMaugh]), Spencer Fullerton Baird, Charles Cory (artist Leon L. Pray), Elliot Coues, C. Hart Merriam, Gerrit Miller, Jr. (artist Tertzli), Dan Metz, Ernest Thompson Seton ( = Ernest E. Thompson), Vernon Bailey, Elva Hamersrtom-Paulson, D. G. Elliot, W. H. Flower and R. Lydekker, H. E. Anthony, William J. Hamilton, Jr., Will-

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iam T. Hornaday, E. Raymond Hall, W. H. Burt (artist Richard Philip Grossenheider), John Dean Caton, Cantlon and Garry A. Heidt, Baron Georges Cuvier, John Litvaitis, Joseph Holder and Sir John Richardson et alia, James Bee and Hall, Susan E. Smith; Tom Swearingen, Thornton Burgess, Karl Schmidt (artist Walter A. Weber) and artist G. Mutzel in Wood’s Nat. Hist (a favorite book from the author’s Grandmother Long (J. G. Wood, 1865). My son Alan made the muskrat years ago (1985). Virginia Peterson and the Houghton Mifflin Co. gave permission to photocopy two drawings by Roger Tory Peterson. Elizabeth Schwartz and the University of Missouri Press gave permission to use two drawings by Charles Schwartz. Other artists are credited in the legends herein. While living, my former teacher E. Raymond Hall gave permission to use several drawings. The styles include stylized scratchboard-sketches, steel cuts, woodcuts, and zinc engravings. Color prints were provided by Virgil Beck and Clark Bronson. This book could not have been published without Harold (“Hal”) Roberts. I told him more than once that he was “one of the nicest men that my wife and I ever knew”. Unassuming, kind, a true naturalist, he was and is always helpful. Military service interrupted several years of his graduate work at UWMadison, where he took every possible course he could from Aldo Leopold and had obtained a masters degree. All together we hope to express tribute to nature, and wildlife poetry and art!

INTRODUCTION THE WILD MAMMAL FAUNA “Wild” mammals try to survive in nature without human care, not as provided for “domestic” mammals. They are seldom seen, for most are secretive and nocturnal. Many spend the day, some the entire winter in burrows. Mammals have attractive ellipsoid bodies, with graceful legs and movements providing swift locomotion. Their warm-blooded bodies are generally covered with hair (i.e., fur) often richly colored. It may be coarse, felt-like, or soft, and often is marked in tasteful patterns. The eyes are large, bright, and expressive, except in the bats, shrews, and moles. Mammals are endeared to us because of their interesting ways and intelligence, to some extent having behavior almost human. Technically, a mammal is a vertebrate animal noted for its fur (technically called pelage) and for the maternal behavior of nursing (i.e., suckling) its young. Mammals evolved long ago from mammal-like reptiles, in the Triassic geological period. Although mammary glands and hair were never fossilized, the fossil record of skeletal transition from reptile to mammal, especially in South Africa, can be traced out stage by succeeding stage. Searching in stratified rocks down into the earth, back into the stony records of many millions of years ago, transitional specimens have been found showing a regular trend of replacing the archaic, reptilian jaw connection with a brand new jaw joint on each side. Replacement began (of course, on either side) by doubling the jaw hinges, i.e., adding an articulation between a newly evolved squamosal bone of the cranium with the adjacent dentary bone of the lower jaw. By subsequently reducing the older (quadrate-articular hinge) of each newly doubled jaw joint, while gradually enlarging the newer squamosal-dentary joint, the “new” and “old” joints, paired together on each side, define those fossils (having “two articulations”) as “mammal-like.” The

derived “ true mammals” almost lost the older, reptilian quadrate-articular hinge, but not quite. A consequential attachment of the old, non-functional hinge (both bones already connected together) to the nearby reptilian hearing bone called the stapes formed a new “chain of ossicles.” That is how the derived “true mammals” came to possess three ossicles in each ear instead of one. Gould (1990) cogently called this story “an earful of jaw”. All three bones, “malleus” (descended from the articular), “incus” (from the quadrate) and even the “stapes” (a transformed hyomandibular jaw bone of fishes) were originally jaw bones in ancient fishes. Archaic mammals from the late Triassic Period were probably warm-blooded. Tactile bristles, such as those on the scaly tail of the recent-day opossum, spread over the body conserving internal heat (Long, 1972b). There are two, perhaps more, comprehensive accounts on mammalian hair (Ryder, 1973; Noback, 1951). Long (1972) proposed that Darwin’s speculation on the origin of lactation in primitive mammals was correct. Darwin had believed the mammae first appeared in the pouch. Long believed glandular moistening of the egg and young in a pouch provided an ever-improving nutrition that became “milk”. This sequence of associated microevolutionary preadaptations fits well with neo-Darwinism. Long (1969c) reviewed the evolution of mammary glands. Other characters seen only in mammals include a diaphragm to enhance breathing, a large cerebrum related to intelligence, and the loss of the nucleus from every red blood cell leaving only a membrane and net-like cytoskeleton of biconcave form containing endoplasma and hemoglobin. It has a great surface area for water and gas exchange. This deformable erythrocyte is driven in blood plasma into tiny capillaries, and easily unloads oxygen to the tissues (Long,2006). There are 69 to 75 kinds of mammals that are considered wild Wisconsin species. A species is a population of organisms that INTRODUCTION

11

breed among themselves, but seldom interbreed with other species. If hybrids occasionally are found, especially those resulting from pairing in captivity, the two stocks are usually regarded as separate species, not necessarily as “good” species. The short-tailed prairie deer mouse (Peromyscus maniculatus bairdii) possibly in one or two places far away, in western states, shows evidence of intergradation with long-tailed deer mice. That is actually little evidence to prove that this little mouse hybridizes freely with any race of maniculatus (which is a long-tailed climbing species). In any case, bairdii acts as a “good” species in the Wisconsin fauna, not hybridizing naturally with long-tailed deer mice, and, therefore, is added to the Wisconsin species count. Jackson (1961) did the same; and Baker (1983) described them separately. Some workers consider the prairie vole race Microtus ochrogaster minor to be a valid species, and it may be (see account of M. ochrogaster). The introduced European stone marten Martes foina is now established in southeast Wisconsin (Long, 1995). The introduced Norway rat and house mouse were established long ago. Removed from this Wisconsin faunal list are the native elk Cervus elaphus [C. e. canadensis Erxleben], bison Bison bison, wolverine Gulo gulo [= G. g. luscus (Linnaeus)], mountain lion Felis concolor [F. c. schorgeri Jackson], and caribou Rangifer tarandus [R. t. caribou (Gmelin)] because they were eradicated at the turn of the 20th century. The elk was reintroduced (see Reintroductions) more than once, and now is protected on a preserve in northwest Wisconsin, as well as many hunting preserves. The bison is now raised as a domestic beef animal on many game farms in Wisconsin. The mountain lion, also called cougar (Felis concolor), probably has been released by unauthorized individuals leading to some of the numerous reports of cougars in Wisconsin; however, there is no verified population, or even a recent specimen or photo of the cougar. I learned of a likely re-

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lease (female or pair) in the Blue River area of two pets brought here from Florida about 25 years ago. At least three of our mapped Wisconsin species may have recently been extirpated. Therefore, our recognized fauna (6869 species) may have declined. Many Wisconsin species have two or even three geographic races, called subspecies, so that the number of named kinds is about 79 (a few less than recognized by Jackson, 1961). If the problematical elk, bison, wolverine, mountain lion, and caribou, and the minor prairie vole, were all added to the total, the number of species rises to 75. The feral house cat, and escaped fallow and Sika deer add species, but are not included; without human support they would likely disappear, and the two released deer probably have. The house cat is usually a domestic pet. The domestic horse (Equus caballus) is not wild in Wisconsin. Humans and domestic dogs have long been on the scene in Wisconsin, but are not a wild resource. The 69 species treated herein, including the probable prairie deer mouse species, provisional stone marten, and three possibly extirpated species (not found in recent years), are classified into distinct accounts. Some of these species have no close relatives; others are grouped in “taxa” of two or more species of similar form. These groups are called genera (the singular is genus). There are about 49 genera; some recognize Microsorex as distinct from Sorex, Eutamias as distinct from Tamias, and Pitymys as distinct from Microtus. There is controversy whether or not to call the Canada lynx and bobcat Felis instead of Lynx, either use does not change the number of genera. Neovison for mink adds one. The genera are classed in 17 families belonging to 7 orders. These orders are the primitive Marsupialia and Insectivora, aerial bats Chiroptera, rabbit and hares Lagomorpha, abundant rodents Rodentia, famous meat-eaters Carnivora, and hoofed Artiodactyla.

IMPORTANCE

OF

MAMMALS

Mammals are important to the people in Wisconsin. On the positive side, they help fulfill human needs for nature. They provide aesthetic experiences, i.e., life-long memories fondly recalled. They have provided substance for literary anecdotes, legends and tales inspiring intellectual communication among people. They furnish highly valued recreation for hunters, and flesh to eat. The deer hunting alone adds millions of dollars to the state economy. Furbearers provide fur for warmth and decoration. Many small mammals serve as foods for carnivores and raptors, and their burrows may be taken over for shelter by other mammals. The burrows of some mammals (e.g., North American badgers, ground squirrels, pocket gophers, moles, and innumerable mice) turn up soil, aerate it, provide nutrients, and facilitate natural soil formation. The beaver turns riparian forestland into vast meadowlands. There are many mammals considered beneficial because they eat insects (as do shrews, moles, especially bats, and to lesser extent numerous other species that occasionally eat them). Some mammals are beneficial because they prey on the injurious mice and rabbits. Much carrion is consumed by opossums, carnivores, and many other mammals. On the negative side, rodents and rabbits steal our crops and girdle small trees and bushes. The white-tailed deer, lovely and graceful as it is, causes over a million dollars damage to Wisconsin crops annually, hundreds of thousands of dollars damage to cars, and in recent years unknown but immense costs for damage in urban landscaping. In recent years outbreaks of urban deer have devastated gardens and shrubbery. The scriptures call for a tithe of our land to nature, but deer, rabbits and rodents often eat more than a tithe, sometimes everything we grow. Although generally beneficial, weasels, raccoons, skunks, opossums, and foxes occasionally may eat the farmer’s chickens. Some large canids have preyed on domestic animals.

Some mammals carry deadly diseases (Table Intro-1; Davis et al., 1987), which they transmit directly or indirectly by parasitic ticks and fleas (such as plague, Rocky Mountain spotted fever, and Lyme disease). Rabies in Wisconsin is caused by a virus known in dogs, cats, cattle, foxes, bats and especially striped skunks (Table Intro-2). Rabies, also discussed below under bats (Chiroptera), foxes, raccoon, and striped skunk, is a terrible disease and always fatal in humans. Usually transmitted by mammal bites, rabies can be prevented by vaccinations. Hantavirus killed one student in Kansas, that collected mice. In the years 1996-1997, recent cases include one person killed in northern Illinois, and another person almost killed (April-May, 1997) from Chippewa Falls, who cleaned a mouse nest out of an old car. Additionally, about 20 kinds of mammals carry hemorrhagic and arbovirus diseases (Davis et al., 1987), and others are involved with plague, tularemia, typhus, spotted fever and other diseases (Childs et al., 1995; Mills et al., 1995; Gage et al., 1995; Schmid, 1985). Even wild animals sold as pets may harbor deadly diseases, such as “monkey pox” in African rodents and American prairie dogs. Lyme disease is caused by a bacterium Borrelia carried by the ticks Ixodes dammini and I. scapularis, and perhaps in other Ixodes. Untreated, the disease is dangerous. Borrelia is reported in Wisconsin in foxes and coyotes (Kazmierczak and Burgess, 1989), bears (Kazmierczak et al. 1998), and small mammals (Godsey et al. 1987; Walker et al., 1996). See status in Caporale et al. (2005). Arboviruses, those transmitted by arthropods, include in Wisconsin the La Crosse encephalitis virus, and probably the St. Louis virus, transmitted by mosquitoes. The La Crosse virus is reported in red and gray foxes, raccoons, and opossums (Amundson and Yuill, 1981 b). Tamias striatus also carries this virus (Gauld et al., 1975), as do Sciurus and Glaucomys (Seymour and Yuill, 1981). Herpes was reported in cottontails (Schmidt INTRODUCTION

13

Table Intro-1 Intro-1. Important infectious diseases of Wisconsin’s wild mammals. Most can afflict humankind. Additional diseases include tuberculosis, herpes, W. Nile virus, and possibly terrorist dangers such as hoof and mouth and anthrax particularly in our artiodactyls. Rodents are susceptible to plague. Davis et al., 1987, and sources cited in text.

Mammals

Rabies Distem- Hemorrhagic Several Tulare- Rocky Brucello- HistoOther Diseases =X per Diseases Arbomia Mtn. sis plasmosis PseudoX, Hanta viruses Spotted TB Virus Fever

Opossum Some bats X E. cottontail P-TB Lepus P-TB Marmota Tamias Eutamias Sciurus Tamiasciurus Harvest mouse Peromyscus Clethrionomys P-TB Microtus P-TB Ondatra P-TB Porcupine Beaver P-TB Wolf X Coyote, Foxes XX, P-TB Raccoon X, P-TB Mink P-TB Weasels Mephitis X Lontra P-TB Taxidea Martes Martes Bobcat X Cervus elaphus P-TB Odocoileus P-TB Alces Bison Rattus Mus musculis Felis catus X

X

X

X X

X X X X X X

X X X X, Hanta virus

X XX X X X

X

X X

X X

X X X X

?X?X X X

X

X

Lyme Disease X Errington’s enc.

XX X

? ? ?

Mange, Parvo-virus Mange,Parv. Blastomycosis Parvo, St. Louis enc. Lyme dis. tick

X X

X X

St. Louis enc.

X

?X

X X

X

X

X

X X

X

X X X(rare) X X

Canine hep. Plague

X X X X X X X X

X X X

et al., 1992) and considered in relation to flea parasitism by Spieker and Yuill (1976). Arboviruses in deer populations were surveyed by Murphy (1989). The recent invasion into the United States, and into Wisconsin, of the West Nile virus, carried by mosquitoes, mostly affects birds such as crows. However, it is transmitted to mammals (e.g, horses, humans) and can cause and already has caused some human mortality.

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X


X

X

Salmonella, Lyme Disease

X X X

Plague Mange, Parv.

Tularemia is an important zoonotic disease found in cottontails, hares, beavers, muskrats, voles, red fox, gray fox, Mustela, and North American badger (Addison et al., 1987). The carnivores often get the disease by scavenging carcasses. Distemper was found in wild and domestic dogs, the raccoon, mink, striped skunk, badger, least weasel, and Microtus pennsylvanicus. Ringworm was found in juvenile muskrats.

Table Intro-2 Intro-2. Rabies in Wisconsin mammals (19521974). Vaccinations have practically eliminated dog rabies. Bats are low. Year/bats

Skunks

Dogs

Total

Skunk, Bat/Total

1974/ 2 1973/ 9 1972/ 8 1971/10* 1970/ 4 1969/ 4 1968/ 6 1967/ 1 Totals 51 1966/ 1 1965/ 1 1964/ 6 1963/ 5 1962/ 5 1961/ 2 1960/ 0 1959/ 1 1958/ 3 1957/ 6 1956/ 0 1955/ 0 1954/ 0 1953/ 0 1952/ 0 Totals 30

68 76 96* 46 33 21 21 28 389 22 21 12 17 12 5 5 64 184* 37 13 19 36 25 27 499

17 35* 24 15 11 6 13 11 132 — — — — — — — — — — — — — — — —

107 154 163 91 60 46 54 61 736 68 64 95 62 42 30 24 92 227* 74 41 39 90 49 56 1,053

.64//.02 .49//.06 .59//.05 .51//.11 .55//.07 .46//.09 .39//.11 .46//.02 .53//.07 .32//.01 .33//.02 .13//.06 .27//.08 .29//.12 .17//.07 .21//.00 .70*//.01 .81*//.01 .50//.08 .32//.00 .49//.00 .40//.00 .51//.00 .48//.00 .47//.03

Anthrax outbreaks, usually arising from soil, are dangerous to many grazing mammals, and especially those that wallow in mud, such as bison. Unknown in Wisconsin, it is, nevertheless, an imminent threat to man and beast, harbored by terrorists and other beasts, and is often disseminated by carrion eaters, ranging from gulls to coyotes. Much the same can be said for bovine TB (= brucellosus) (see Davis et al., 1981). Parvoviruses are often lethal to carnivores, especially to dogs; this dog virus may have mutated from the feline parvovirus. The canine strain of virus went around the world in the brief interval 1976-1980, providing an example of the incredible cosmopolitan danger of mutated viruses dispersing in short times, and the importance of mammals in transmitting viruses. Today it is found in coyotes, red foxes, raccoons, and probably the

Cases of rabies in the United States in wild mammals, 1955-1991. Krebs et al., 1992. Raccoon incidence is highest in eastern states.

Rabies in domestic and wild mammals in Wisconsin 1953-1992. Rare since then in domestic animals.

wolf, at least in some states. The incidence was reviewed for several species by Short (1989). Vaccination helps control parvovirus, protecting our domestic dogs, and has practically rid the country of rabies in dogs. Rapid action by government and the Department of Natural Resources hopefully can prevent a great calamity following discovery (winter 2001-2002) of Chronic Wasting Disease in deer near Mt. Horeb. This disease, caused by virus-like “prions” that attack the central nervous system, is lethal, and, transmitted by unknown means, threatens to decimate the entire Wisconsin deer population. That would create an economic disaster, because of the economic importance of deer INTRODUCTION

15

hunting. See account below of the white-tailed deer and see Manwell (2001). The introduced Rattus and Mus defile our homes and belongings, as well as bringing us diseases. The house cat, either feral or domestic, eats millions of mammals and our wonderful songbirds (Coleman, 1993). Any time a mammal reproduces to excess, a problem develops, whether the mammal is as small as house mice or as large as the whitetailed deer. Usually mammal populations are kept in line, especially by predation, diseases, and starvation. Raptors certainly do their work limiting population outbreaks of small rodents. Therefore, biodiversity in nature, a desired goal of modern conservation, actually benefits the entire ecosystem and most of its members because of the so-called “balances” in nature. Mortality in wild mammals is generally equal to natality (birth rate). In time they balance, so long as populations are stable. Both subjects (mortality and reproduction) are treated herein. In nature, potential longevity (see Appendix A) is usually shortened by natural mortality or hunting and trapping harvests. Most mammals should not be judged as bad or good, but managed for a useful function in the community. “Useful” includes econ-

16


omy and aesthetics, i.e., harmony and beauty. If a creature lives in association with humankind, it should be studied carefully by people with training so that by scientific management the negatives can be minimized and positives can be emphasized. The status and conservation of wild mammals must be continually studied. Then the problems of co-existence of human and animal may be recognized and solved. Modern-day land use has cost us some irreplaceable species. Wise management has saved some valuable species and replaced others. Today there are famous societies and agencies that set aside habitats, regulate some populations, and conduct research on mammals that need support. There are other agencies, landowners, and users that care little about preservation. They must be opposed. We should let no mammal, no matter how little or secretive it is, escape our notice and protection. Those who undertake the study of mammals, or any wild creatures for that matter, will find them far more interesting and valuable than they ever might have imagined. Hopefully this work will bring the subject of Wisconsin mammalogy, especially biology and known status of the wild mammals, up to date, at least to 2007.

PLAN OF THIS BOOK “In pursuing our researches we are often compelled to differ from the views of previous writers. . . . we will endeavor to be swayed simply by a love of truth, treating all with respect, and adopting such language as can be offensive to none.” – John James Audubon and John Bachman, The quadrupeds of North America 1842-1846.

SCOPE

AND

PLAN

In this book, the 20th century mammals of Wisconsin are emphasized, but some information is included on prehistoric mammals and those mammals extirpated during the 19th century. The Prehistoric Mammals are discussed in a separate section. The Wisconsin mammals documented in historic and scientific literature but extirpated before 1900, and some species that may be found in Wisconsin but are unverified so far (Hypothetical Species, Reintroduced and Extirpated Mammals beyond) are briefly discussed. The treatment of the mammals is taxonomic; the classification is based on evolutionary relationships including even the integral concepts from ecology and physiology. Unlike humans, fettered but diversified by customs, fads and television, the wild mammal lives an odyssey more genetically programmed, common to its kind. Success for a wild mammal is survival and successful reproduction. Naturalists say the mammal “prefers” a particular habitat. It occurs in this habitat partly by preference. Usually it was born there, of parents and ancestors adapted to it, as beavers are born near water, prairie mammals in grasslands, or forest mammals amid trees. Since “habitat” means home in a general way, the den site and nest for most mammals is its important home within a home. The beginning of the odyssey, called “dispersal” by scientists, is departure from the natal den. Actually it is weaning, the departure from mother. This rejection may happen in the natal den or near-

by, or at some outlier used as a den. The young beaver walks or swims away, the bat flies off, the mole burrows, and the leveret hare jumps across the prairie. They search for food sources and den sites, adventures shape their destinies, the winds carry the bats to strange places, and eventually each mammal has sexual yearnings. The dispersing young mammal must find a home or resting place, for security, sleeping, and for its offspring. Perhaps it selects a tree cavity, or digs or appropriates a burrow. Eventually the mammal may breed and bring forth young hopefully with the same adaptations that served the parents. The genetic program for form and function passes from parents to offspring. Thus, it is important for us to determine what kind a mammal is (description and names are provided herein) and where it can be found (geographic range or distribution and status). The habitat and home are described. Foods, mortality, and reproduction are reviewed. Population parameters are discussed, such as the extent of a species home range and how abundant it is within an area (density). Under Remarks various subjects are discussed. Speciation is ascertained for Geographic Variation. The specimens, mostly in museum collections, are ascribed to county. Some general and characteristic adaptations, and their phylogeny, are usually discussed for the higher taxonomic categories, such as wings in bats, bunodont molars in bears, or slenderness in weasels. All of this is modern taxonomy, and all is based on paleontology, physiology, morphology, and ecology, important and inseparable concepts. The mammals of Upper Michigan cannot be separated from the Wisconsin fauna except by the political boundary drawn between the states. There is no apology necessary for confining an investigation to an unnaturally bounded region, such as a state, but in my opinion the Upper Peninsula is so continuous with Wisconsin ecologically that this entire natural region should be appraised as one. There is continuity of southern WisconPLAN OF THIS BOOK

17

sin and northern Illinois, and on occasion (e.g., for Cryptotis, Nycticeius, Pitymys) I also ignore that political boundary. Nevertheless, the specimens studied herein, in the main, are from Wisconsin, and the book is essentially about Wisconsin mammals. The east (Lake Michigan) and west (Mississippi River) boundaries of Wisconsin are barriers sharply limiting geographic range of some mammals. Modern comprehensive references for the surrounding states are Baker (1983) for Michigan, Hoffmeister (1989) for Illinois, Bowles (1975) for Iowa, and Hazard (1982) for Minnesota. Wisconsin mammals have been wonderfully studied in the past by Cory (1912), and the late Hartley H.T. Jackson (1961), a Wisconsinite formerly of the U.S. Biological Survey. The reader is urged to consult these fine books. No comprehensive work in Wisconsin has appeared since Jackson’s book, written over 40 years ago. The taxonomic sequence of species used follows that of Hall (1981), with exceptions explained in the accounts. Comments describe variation on geographic variation, because it is such a nebulous concept, and is usually referred to subspecies, i.e.races. They appear alphabetically, unless otherwise noted. However, the nominate race is mentioned first if present in the state. A controversy today in mammalogy is what to do with geographic races, formally called subspecies. These kinds are named and described with trinomens, and too many were based on trivial characters. However, some are quite distinctive, and others were discovered by carefully appraised comparisons made on specimens collected over a wide region. Once considered as incipient species the subspecies at best is a recognizable population more or less adapted to a geographic region. Changes in habitats and other ecological factors may have affected the gene frequencies and phenotypes (appearance) of this struggling population, but a distinctive geographic race has genetic properties passed on for generations, usually for thousands of years. An isolated

18


fragment of a population may undergo speciation leading to the evolution of a new kind. It follows that some races are differentiated as quite distinct, as are the Florida and Wisconsin fox squirrels. The prairie and forest deer mice in Wisconsin are distinct. Other races seem less distinctive and may be recognized only by careful comparisons of average and significant differences from place to place. If I perceive the described geographical differences, the formal names seem appropriate to me. If a former student of geographic variation drew a line arbitrarily between two different kinds, I may follow his lead. This book attempts to provide rationales for using current scientific (Latinized, postLinnaean) names. It broadens the statewide study enough to ascertain geographic variation extending into some other states. There is no aim toward revising the taxonomy of mammal species and subspecies in adjacent states. I searched for resemblance in characters in neighboring states to assign some Wisconsin mammals to their taxa. The foregoing rationales for formal classification of geographic variation would not be necessary to convince the scholars Hoffmeister (1989) and Jackson (1961), who studiously attempted to make careful taxonomic assignments in this region. This raised a peculiar problem for Wisconsin and Illinois. The political boundary between Illinois and Wisconsin unrealistically separates some geographic races. This dilemma arose in part from inadequacies of earlier studies and in part from numerous taxonomists assigning specimens on geographic grounds to either the nominate subspecies or the nearest geographic race. Respect for colleagues and their use of names often resulted in illogical acceptance of a name based on trivial or invalid characters. The divergent views of the aforementioned two men often obtained different results. Fourteen pairs of subspecies are divided by the Wisconsin-Illinois border, called herein the Hoffmeister-Jackson Phenomena (Table Plan-1). They defy the tenets of specia-

tion (e.g., geographic barriers, or former climates (Long, 1965) that separate evolving populations). Some reasons for this pattern include (1) natural hiatuses barring population movements, i.e., valid taxonomy, (2) provisional names, and (3) utter speculations. Wisconsin taxa are listed first. Synonymies are used to head up the species and subspecies accounts. These list the original use of name for a described kind of mammal (the scientific name is immediately followed by the Author’s name, which is not printed in italics). The synonymy also includes changed names, the most modern or recent name combination with the name of the taxonomist who first published that combination. Obviously all published usages of popular mammal names today need not to be cited. Between the name of the author of a new name combination (not for the original name itself) and that combination is a colon, because the International Code on Zoological Nomenclature recommends that kind of punctuation be used. To follow that recommendation defies some precedence in mammalogy. Other names listed in the synonymy include invalid

synonyms and homonyms with their authors’ names. The citations are sufficient enough, so they need not be duplicated in the Literature Cited (unless they need to be cited elsewhere in text). The use of parentheses around an author’s name in the synonymy means that the author named the mammal with a different generic name in the binomen or trinomen combination than is presently used. A scholar, then, would never look for the scientific name Cryptotis parva (Say) in old literature. In fact, the original combination was Sorex parvus Say. Most geographic distributions are discussed with reference to state maps. The entire North American geographic range of each species (after Hall, 1981). is presented in an accompanying map of North America. Where there is information available, such as for some Wisconsin carnivores, maps based on Department of Natural Resources work showing primary range, or denoting rare, less common and common occurrence are often included. The dots on the state maps are black for specimens I have examined, and bull’s-eyes or open circles for other records from Jackson

Table Plan-1. The Wisconsin-Illinois border separates 14 pairs of subspecies.

Disjunct pairs caused by a natural hiatus, due probably to former climate Synaptomys cooperi Geomys bursarius Lontra canadensis

cooperi Baird wisconsinensis Jackson canadensis (Schreber)

gossii (Coues) illinoensis Komarke & Spencer* lataxina Cuvier

Races not carefully identified, or given hypothetical names Mus musculus Castor canadensis Canis lupus Felis concolor

M. m. rutty michiganensis Bailey lycaon schorgeri

? carolinensis Rhoades ? ?

hypophaeus Merriam minnesota Allen noveboracensis (Fisher) ocythous Bangs hirtus Nelson & Goldman hudsonica Richardson superiorensis Peterson & Downing

pennsylvanicus Ord loquax (Bangs) leucopus (Rafinesque) cinereoargenteus (Schreber) lotor Linnaeus avia Bangs rufus Schreber

Problematic taxonomy Sciurus carolinensis Tamiasciurus hudsonicus Peromyscus leucopus Urocyon cinereoargenteus Procyon lotor Mephitis mephitis Lynx rufus

PLAN OF THIS BOOK

19

(1961) for Wisconsin and from Burt (1948) for Upper Michigan. Other symbols are occasionally used for personal observations, examination of road kills, and other valid records. Most “other records” in this study are designated with open dots. Therefore, for most of the state maps the black dots may be compared with the bull’seyes or open circles to roughly appraise and compare the present and earlier distributions. Some changes in distribution are delineated with bold dashed lines. (Smaller dashed lines already were on the outline maps; they delineate drainage divides.) When localities are dubious or near one another, I arbitrarily chose one good locality for mapping and the others unplotted are italicized in the records of specimens. The comparison of ranges past and present show real changes (in which I follow the ornithologists in calling shifts “dispersal”). In some cases, such as many in Wisconsin, the change observed is in known range (where the specimens were recently obtained, unseen by Jackson). Usually it is possible to distinguish one change in geographic range from the other. The descriptions include cranial and anatomical characters, color of pelage, dental formula, size and other known traits. Terms for color are from common lay use unless quoted verbatim from studies of other workers. Terms such as narrow, or narrower zygomata, or elongate, and such qualitative generalities are most useful when actual specimens are examined. The drawings and photographs of skulls should be consulted. The finest set of mammal skull drawings I have seen are in Hall (1981) or Hall and Kelson (1959). Dental formulas used herein are the sequence of incisors, canines, premolars, and molars, written for humans (as an example) as DF= I 2/2, C 1/1, P 2/2, M 3/3 = 32. The premolars 1-2 are not the first and second ones; they are the posterior third and fourth premolars because in evolution the anterior premolars are first lost. The total 32 is a product of the summed teeth on either

20


side times two. The dental formula was developed after Baron Georges Cuvier had tabulated comparative formulas for numerous mammals to express serial analogy. Unless there is solid evidence to identify a tooth as one kind or another, and especially in the problematic insectivores, I prefer to avoid use of implied homologies, and prefer to use descriptive symbols such as B for bicusp or bicuspid, U for unicusp (above) and unicuspid (below), and so on. In the section Insectivora further problems with the nomenclature of these so-called unicusps are discussed. I have been advised to at least refer to the first tooth above in shrews as an incisor, but am not convinced it is the first incisor. An upper fourth premolar is given as P 4/, and P /4 is the lower analog. External and cranial measurements and many other terms used herein are defined in the Glossary. Measurements usually are in millimeters. Dial calipers were used to measure the skulls. For weights and some linear measurements either English or metric may be quoted, and in instances where the writing is difficult and jerky from switching back and forth, both values may be given together. I am persuaded to provide both values, because of both general and scientific readers. Appendix B at the end of this book provides a conversion table for English and Metric Measurements. Statistics given, unless cited from another worker, will provide individual measurements, or if the number (N) is practical the mean usually will be calculated. The observed ranges and standard deviation are often listed in the tables. After each account there is Additional Natural History, including one or more works cited and otherwise deemed appropriate. There is no intent to be judgmental or comprehensive in so doing, some fine works may be left out. Finally, geographic variation is described and discussed. In Specimens Examined, counties are listed alphabetically for easy reference. The county names and their locations are shown in the

aforementioned map of counties and type localities. In addition to the specimens I have examined from the UW-SP collection, I have examined hundreds of University of Wisconsin—Madison museum specimens (UW) documented by Jackson (1961). To preserve the aforementioned rough comparison between the distributional ranges of his day and mine seldom did I blacken up the circles on the maps used to represent his old records, even after I had seen them, or list those specimens with my specimens examined. They are listed in his book. With Frank Iwen’s (Univ. Wisconsin Madison, Museum of Zoology) help, I tried to examine important UW specimens accumulated since 1961. Some specimens examined by me in the University of Minnesota Bell Museum are listed as UMinn., in the Illinois Museum of Natural History collection as UI, and in the U.S. National Museum as USNM. Dr. Scott Craven permitted me to examine a useful collection in the Wildlife Ecology Laboratories in Madison (UW-Wild. Ecol.). Although some state accounts today omit precise localities taken from specimen labels, there are important reasons to list them. Other taxonomists then learn about the specimens, which they may borrow for their research. If the specimens become lost or destroyed, too often the case in museum collections, the known occurrence is documented. Re-examination by future taxonomists may uncover errors in identification and lead to geographic range corrections. Against these positives stand two negatives: the work of listing and the expense of publishing. Here, the listing was accomplished, but the cost of publication was hard to defend. I followed a middle road; specific localities were uncommon and marginal records. The Literature Cited and Bibliography include some references used by Jackson (1961), some overlooked therein, many papers cited herein, and some worthy but not fully discussed due to the length and expense. To great extent it is bibliographic since Jackson’s publication.

FREE EXPRESSION

IN

TAXONOMY

Some mammalogists may find some of my divergences from established taxonomy disconcerting, I would like to make clear that the taxonomy one uses may express a view based upon a biological rationale. Darwin (1859) once said, “Naturalists differ most widely in determining what characters are of generic value.” Every species is distinct, and it often becomes subjective to recognize long phylogenetic separation (i.e., generic divergence) from closely resembling (i.e., evolutionarily related) species. In Wisconsin six mammals present dilemmas: (Microsorex and Sorex, Eutamias and Tamias, Pitymys and Microtus, Mustela and Neovison, Lontra and Lutra, Lynx and Felis). Some add Puma and Felis and Bison and Bos. Nomenclature is a system based on rules and regulations compiled and published in the International Code of Zoological Nomenclature, revised and amended by an International Commission. The Code provides for the free expression of diverse classification. Alternative expression is welcome. Opinions may be consigned to synonymy by other workers hopefully by presenting new evidence.*

PRESERVATION OF SPECIMEN COLLECTIONS AND HABITATS When wild mammals are studied and carcasses obtained or salvaged, voucher specimens should be made and preserved. Students making a study should do it themselves as a nec* The interested reader is referred to an excellent and recent synopsis on the subject of mammalian taxonomy edited by Wilson and Reeder (1993, 2005). For higher categories, Simpson (1945) and McKenna and Bell (1997) are recommended. Highly recommended is the new The Smithsonian Book of Mammals, by the same Wilson with Sue Ruff (1999) and a host of contributors. A revised Wild mammals of North America updating Chapman and Feldhamer (1982) has appeared. PLAN OF THIS BOOK

21

essary part of that study. Although difficult, time consuming, and requiring skill, invaluable vouchers should be deposited in a permanent repository, i.e., a museum collection. Specimens should be well made, including at the least a skin and skull with labels (Appendix C). Today frozen tissues and soft tissues preserved in alcohol often are preserved. Permanent field notes should be kept with the specimens, and all information obtained should be accurate, complete as possible, and meant for permanent record. If there is no way to preserve a specimen, even by putting it in a jar of alcohol, or saving the skull or teeth of a decomposed carcass, the carcass may be turned over to a mammalogist. That lays a burden on someone else to make up the specimen. Most of the work herein is based on collections of mammals gathered in the last quarter century. Such collections are priceless. Wisconsin specimens are found in several state collections and in several public museums outside Wisconsin, but I have not attempted to document every specimen. The Mammal Collection at the University of WisconsinStevens Point Museum of Natural History is one of several large vertebrate and invertebrate museum collections. The Museum, a division of the University of Wisconsin— Stevens Point, is supposed a responsibility of the University of Wisconsin System. The Museum has been the foremost university museum in the state in research collections, exhibits, and museum activities. The Museum of Zoology at the Madison campus has about as many or more mammal specimens, mostly representing earlier collections. The two collections taken together provide a respectable repository of Wisconsin mammals (Tables Plan 2-3). Field notes of many students are preserved, and the Department of Natural Resources has provided some voucher specimens. Some specimens of endangered species have accumulated in the collections throughout the years. On the basis of the museum specimens, significant taxonomic changes, since l961,

22


Table Plan-2 Plan-2. The UW-SP Mammal Collection, the Wisconsin specimens. The Museum contains specimens preserved from nearby states of the several species not in this collection. It contains specimens of Myotis sodalis, Nycticeius humeralis, Gulo gulo, Spilogale putorius, Cervus elaphus, Bison bison, and Rangifer tarandus. Order Marsupialia Insectivora Chiroptera Lagomorpha Rodentia Carnivora Artiodactyla

Families

Genera

Species

1 2 1 1 6 5 1

1 5 6 2 21 11 2

1 8 7 3 27 17 2

Table Plan-3. Wisconsin specimens at the UW-Madison Museum. Archaeological bison and the introduced stone marten are included. Order Marsupialia Insectivora Chiroptera Lagomorpha Rodentia Carnivora Artiodactyla

Families

Genera

Species

1 2 1 1 6 5 2

1 5 5 2 21 11 3

1 7 7 3 27 19 3

have been made or will be for the following species: Sorex (Microsorex) hoyi, Tamias striatus, Sciurus carolinensis, Castor canadensis, Microtus (= Pitymys) ochrogaster, Microtus (= Pitymys) pinetorum), Peromyscus maniculatus, Urocyon cinereoargenteus, and lesser changes for others.

COUNTIES

AND

TYPE LOCALITIES

The counties with their names are shown on the accompanying map. The records of occurrence of mammals studied in this book are mapped for the counties, which are listed alphabetically. Because a boreal-southern division of mammals is important, it is good to know northern counties from southern. The northern ones are often toward the beginning of the alphabet (such as Ashland, Burnett,

Bayfield). Exceptions such as Washburn, Sawyer, Iron and Vilas are quickly learned. The Door Peninsula, important for the geography of Wisconsin mammals, is primarily Door County. The populous southeastern counties are known by big cities of the same name (Racine, Waukesha, and Milwaukee). In central Wisconsin is a square of three counties (Marathon, Wood and Portage) where much of the University of Wisconsin-Stevens Point mammal collection was collected. Similarly, the Madison collection is mostly from Dane, Columbia and Sauk counties. For convenience, the 17 type localities of mammals named from Wisconsin are plotted on the county map. A type locality is the loca-

tion where a mammal specimen was collected and subsequently chosen to represent a subspecies or species of mammal named formally in a scientific published work. Other specimens from that same locality are called topotypes, and they, with or without the type (= holotype), are important for taxonomic comparisons of one named kind with another, to associate specimens from other places in the same kinds. Most but not all named kinds from Wisconsin are valid names in use today. All the names based on types collected at our type localities are available for future taxonomic opinions. All are cited in the Synonymies that head up the species and subspecies accounts beyond. The type localities are as follows:

Map showing counties and type localities. PLAN OF THIS BOOK

23

Ashland County — Basswood Island, Apostle Islands: Canis latrans thamnos Jackson 1949. Clark County — Withee: Sorex palustris hydrobadistes Jackson 1926. Worden Township: Pitymys pinetorum schmidti Jackson 1941. Columbia County — West Point Township: Reithrodontomys megalotis pectoralis Hanson 1944. Door County — Peninsula State Park: Tamias striatus doorsiensis Long 1971. Jessen’s meadow on Swenson Road, Washington Island: Synaptomys cooperi jesseni Long 1987. [Honoring Tom Jessen, type taken nearby on his brother’s meadow.] Douglas County — Lake Superior, probably Valley of the Brule River near Solon Springs, Bruleand Iron rivers. Not Minnesota as reported, because Geomys does not occur on the Minnesota shore or near it. Mus saccatus Mitchill 1821. New York Med. Repository 6:249 (=Geomys bursarius). Grant County — Platteville: Urocyon cinereoargenteus ocythous Bangs 1899. Iowa County — Blue Mounds: Cervus whitneyi Allen 1876. Blue Mounds listed by

Jackson (1961) was omitted from his synonymy, and also by Hall and Kelson (1959) and others. The “lead region” of the Mississippi River is not much like Dane County; in any case, the subfossil elk was considered an extinct fossil species. Nevertheless, it is an available synonym for the American elk. Oconto County — Lakewood: Microsorex hoyi intervectus Jackson 1925. Oneida County — Crescent Lake: Eutamias minimus jacksoni Howell 1925. Outagamie County — Near Appleton: Felis concolor schorgeri Jackson 1955. Racine County — Racine: Sorex hoyi Baird 1858 (= Sorex (Microsorex) hoyi). Probably collected somewhere northward of Racine (Long, 1972a). Racine: Arvicola austerus Le Conte 1853. Richland County — Lone Rock: Geomys bursarius wisconsinensis Jackson 1957. Rock County — Milton, 4 mi. E: Taxidea taxus jacksoni Schantz 1946. No exact locality known except Wisconsin. — Cariacus wisconsinensis Belitz 1919 (= Odocoileus virginianus, see Jackson, 1961).

Rhyme to Louis Agassiz: And he wandered away and away, with Nature the dear old Nurse, Who sang to him night and day the songs of the universe, And when his way seemed long and his heart began to fail, She sang a more wonderful song, Or told a more wonderful tale. — Henry Wadsworth Longfellow

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EARLY MAMMALOGY AND NOW What is mammalogy? It is the study of fourlimbed furry animals secretive and mostly nocturnal. They climb trees or rocks, dig in the ground a little, and are adapted to our grasslands, forests or forest edge. Some species run or hop, and others can even fly. They feed on seeds and nuts, sometimes on fruit or grasses, or instead may specialize on insects or flesh. They may breed in the spring or fall, sometimes throughout summer, and a few may breed in winter. Usually the young are born blind, naked and helpless, but some are more precocial. They nurse, grow, disperse, and try to carry out their life activities faced with mortality from predators and diseases. People observed mammals in what is now Wisconsin over 600 years ago, probably as early as 9,000-11,000 years ago, the time the great Pleistocene mammoths died out. Fishing and hunting were pragmatic activities of native Americans. There were myths and superstitions about mammals. Their lore cannot be regarded as science, even though our science is a changing and imperfect perception of nature (no matter how elegant we believe that it is), we who practice and see our results in retrospect. Retrospection is possible because of publications, books, journals and other written records. Publication and testable science began in Wisconsin with the Caucasians (French, English, Americans). The French established schools, trading posts, and churches in this region about as early as the Pilgrims landed at Plymouth Rock. After the early 1500’s, the active and curious French explored central Canada and our land via the mighty Ottawa River, leading westward from Quebec. Jean Nicolet arrived at Green Bay in 1643, and he was not the first. Some coureurs de bois arrived as early as 1662 (Gilman, 1974). Most of the fur trapping and in early years even the transport to Quebec of the furs were carried out by Native Americans. The various tribes were often at war with one another, displaced from region

to region, and therefore the economics of fur not only affected the history of the American West, but it affected the very early history of Canada and the United States. Fur also profoundly affected the destinies of several Indian nations especially along the Mississippi River, and in Wisconsin and Upper Michigan (see Gilman, 1974). Eventually the city of Sault Ste.-Marie was settled at St. Mary’s Narrows, at the east end of Lake Superior. Explorers such as Etienne Brule, Pierre Radisson, M. Chouart Sieur des Groseilleiers, Perrot, Jean Nicolet, Father Jaques Marquette, Louis Joliet, and Daniel G. Dulhut explored what is now Wisconsin, establishing schools, churches and fur trading posts throughout the region, from Madeleine Island in the Apostles to Green Bay eastward and Prairie du Chien and La Crosse southwestward. The French eventually established settlements along the entire length of the Mississippi River. These activities of developing a fur trade, and eventually of copper mining, fishing and farming all began in the early 1600’s. After the French were defeated at Quebec in 1759, giving up their American possessions in the treaty of 1763, the British ruled as best they could over the wilderness posts and the lucrative fur trade, until 1783. Then, the Treaty of Paris ceded American lands to the United States. Nevertheless, French, British, and Indians, with the help of some Americans, continued shipping furs to European markets. The Americans were kept out by the British troops until about 1815. Eventually the fur trade and other activities were assumed by the Americans, meaning by this term the people from the United States. By 1836, Wisconsin was a territory. Its southern lands were settled by farmers who early on moved along the Lake Michigan shore to French-established Green Bay and the Door Peninsula (named after the strait called Porte des mortsor Door of Death). Lumber was harvested in the center of the region, shipped down the Wisconsin River, and eventually lumbering yielded great quantities of lumber from the EARLY MAMMALOGY AND NOW

25

tall white pines and spruce of the North Woods. Lead and copper were mined in the southwest of Wisconsin. Forest fires were commonplace. The infertile, sandy savannas of the center were eventually settled by farmers. Swamps and marshes were drained, forests cleared, and towns and roads established. Thus, there were, in what is now Wisconsin, several Indian nations, the French, British, Canadian, and American governments. Even Spanish soldiers visited in the southwest parts of this land, after moving up the Mississippi River. For a while the region was known as the Michigan territory. Wisconsin’s borders with Michigan were established by a series of political negotiations. Today there are several Indian nations with more or less authority over the northlands. The earliest French civilization was more accurately a French-Indian civilization, with mixed culture and free intermarriage. Although these races were amicable, there was always trouble between Sioux and Chippewa, Chippewa and Huron, etc. Basically the entire region had developed in one way or another primarily by the economics of fur, until after statehood, after which time the region was settled by farmers, lumbermen, miners, businessmen, immigrants, and descendants. Although scientists in those early years faced formidable challenges, and spent much effort in survival, the French scientists and some others, too, named and described animals from many of the furs obtained in the fur trade at St. Louis and Hudson Bay. None of them is known to have come from Wisconsin. The badger type may have (see Long, 1972) because it was a St. Louis pelt supposedly taken in “les pays des Esquimaux” which generally was French-Canadian fur territory. French explorers such as Joliet and Nicolet made general observations on wild mammals in their accounts of the regions explored. Joliet [“Louis Jolliet”] described a mountain lion in what is now Grant County in 1673 (Jackson, 1961). With the fur trade flourishing in the early 1800’s, H. R. Schoolcraft made several Amer-

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ican government-sponsored expeditions to explore the Michigan Territory. His explorations circled from Sault Ste.-Marie to Grand Marais, to Pictured Rocks, and westward along Lake Superior to the Apostle Islands (in what is now Wisconsin), down the St. Croix and Mississippi rivers as far as Galena, Illinois, and in Wisconsin, Prairie du Chien, then traveling up the Wisconsin River to Portage, northeastward to Green Bay, and back north to Sault Ste.-Marie. He made casual observations (1834) of bears and deer killed, sightings of wolf, porcupine, and in Wisconsin a red fox, beaver and “jerboa” (probably a jumping mouse). This mouse was from Madeleine Island (Mossman, 1992, 1994). On his expeditions Schoolcraft was accompanied by a bona fide scientist named S. L. Mitchill. Mitchill wrote, “Description of two mammiferous animals of North America”, Medical Repository 21: 248-250, 1821, and “Detection of a mistake into which naturalists have been led, in relation to Mus bursarius, or pouched rat of Canada”, Amer. J. Science, 4: 183-185, 1821. In these early years Wisconsin was visited by two of the world’s greatest intellectuals. Both were greatly interested in nature, and only their brief tenure in Wisconsin keeps them from being recognized as Wisconsin’s greatest naturalists. Both were primarily writers and realist philosophers, but they were amateur naturalists besides, with strong interests in making plant specimens. John Muir (1913) arrived from Scotland in the 1840’s and was raised with hard work on a farm at Montello. He left Wisconsin and became an eloquent preservationist of nature, so elegant in prose to be almost biblical, so outraged and stately he resembled a biblical prophet. Never has there been another like him, and nobody from Wisconsin is really educated if he knows nothing of the lyrical and sacred environmental scriptures that he wrote. Muir described the nest and a hibernating specimen of the thirteenlined ground squirrel Spermophilus tridecemlineatus. Quite interesting was the observed

attack (about 1846) of a shrike, even following a ground squirrel into its burrow. The other intellectual giant was Henry David Thoreau, who briefly visited Wisconsin, and paid more attention to mammals than did Muir. Accompanied by Horace Mann, Jr., the transcendental realist Thoreau came by steamboat up the Mississippi River hoping eventually to write up an account of the Great River and the Volga-like towns here and there along the river’s steamboat route. These included Prairie du Chien, La Crosse, Red Wing, Minnesota, and others. Some little towns are still isolated along that river today, although a highway and railroad now extend along the river shore. Thoreau unfortunately died before he wrote the book, although publishing a few articles. His notes are preserved at Harvard University. His favorite mammals were the thirteen-lined ground squirrel Spermophilus tridecemlineatus and the pocket gopher Geomys bursarius (Sweetland, 1962), which is indeed a more interesting mammal than most people realize. The woodcut of Thoreau was made after he returned to New England from Wisconsin, shortly before he died. Several works on the Wisconsin mammal fauna appeared in the late 1800’s. I. A. Lapham (1852-1853) and Moses Strong (1883) wrote lists of the mammals. As early as 1853, Dr. P. R. Hoy wrote a paper on the thirteen-lined ground squirrel. Hoy sent numerous specimens to Spencer Fullerton Baird at the Smithsonian Institution. He actually named with Kennicott a kind of deer mouse found in Wisconsin, named bairdii, and had a shrew Microsorex hoyi (=Sorex (Microsorex) hoyi) named after him by Baird. In 1882, Hoy wrote a brief account of the mammalia of Wisconsin. H. Gillman (1873) wrote an early work on the caribou near Lake Superior. Other naturalists at this time were Charles F. Carr, John Clark, Henry Nehrling, and the two Kumleins (Thure, died 1888; Ludwig, 1880’s). One of the earliest mammalogists living in Wisconsin, and, indeed, the first woman mammalogist in America, was Martha Maxwell. Fa-

John Muir. Great naturalist-philosopher. Raised near Montello. Photo by W. Dasselville, about 1909. Courtesy of the Sierra Club.

Henry David Thoreau. Naturalist and transcendental philosopher. after returning home from Wisconsin Mississippi River trip. Woodcut. EARLY MAMMALOGY AND NOW

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mous for her Colorado exhibition at the 1876 Centennial celebration in Philadelphia, Maxwell was mainly a self-taught collector and taxidermist of birds and mammals. When living in Baraboo she married, had a daughter, and got work at the Baraboo Collegiate Institute. Her work was to assist in the preparation of mounted birds and mammals for the Zoology Department, a practice prevalent at state schools at least until 1906. When she left Wisconsin for Colorado she had learned to observe, study, collect, and prepare specimens mounted in natural positions, including large mammals. She corresponded with Joseph Henry, Secretary at the Smithosonian, and also with Robert Ridgway and Elliot Coues. A screech owl that she collected was named after her by Ridgway. She also confirmed the existence of th black-footed ferret described earlier by Audubon. She attended college in Wisconsin (Lawrence University) at a time when women were generally not welcome in college. Like Muir she subsequently made her fame in a western state. Her collections of specimens apparently are all lost (Stein, 1996), unless a few are in the United States National Museum (Natural History). About 1900, workers from the United States Biological Survey, under the direction of Dr. C. Hart Merriam in the Smithsonian Institution, began to collect specimens in Wisconsin. Two young Wisconsin naturalists, Ned Hollister and Hartley H. T. Jackson, learned about the Smithsonian and actually got jobs with the Biological Survey. Classmates at Milton College, and fellow workers in the Survey, it is not surprising that early works on Wisconsin were produced by both of them. Hollister (1910) wrote an early check-list, and in his youth Jackson (1908) wrote a preliminary listing of Wisconsin mammals. Two scholars who wrote several early papers on Wisconsin mammals at the turn of the 20th century were W. E. Snyder (1902) and H. L. Ward (1907, 1908, 1911). In 1912, C. B. Cory wrote the “Mammals of Wisconsin and Illinois”, which is a comprehensive and well-written book on mammals from southern

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Illinois to boreal Wisconsin. As comprehensive as Jackson’s work on Wisconsin was in 1961, no one should overlook Cory’s practical discussion on any Wisconsin mammal. Dr. Hartley H. T. Jackson (1881-1976) was born in Milton and studied at Milton College. He worked for his masters degree at U.W.-Madison and obtained a doctorate from George Washington University in 1914. His undergraduate teacher was Ludwig Kumlein (see Robbins, 1991). His first paper on Wisconsin mammals was published in 1903. In 1910, he joined the U.S. Biological Survey, and although he spent most of his life outside Wisconsin he may be the greatest naturalist the state has produced. He was instrumental in founding the American Society of Mammalogists, and was a longtime editor for the Journal of Mammalogy. He was a meticulous scholar, and wrote a classic taxonomic monograph on the shrews of North America. He also collaborated with Stanley Young on books such as The Clever Coyote and finally wrote the Mammals of Wisconsin (1961). Aldo Leopold (1899-1948), born a century ago, was a forester acknowledged as a great naturalist-philosopher. His books (e.g., Sand County Almanac, Round River) expound a “land ethic” philosophy. He provided classical foundations for game management, recognition of the ecosystem, and an appreciation of the role of predation in regulating prey populations. For Wisconsin he published on wolves, cottontails, and the “killing technique” of the [long-tailed] weasel. In the 1940’s, bat banding was popular in the caves of Wisconsin. Pioneer bat banding carried out by professors and students at Madison was done at Eagle, John Gray, and nearby caves by John Emlen and William Elder. James Beer, Frederick Greeley, and Arnold Jackson banded bats in southwest Wisconsin, at Lac du Flambeau and sites near Hurley. Wayne Davis, who reviewed the bat accounts herein, and W. Z. Lidicker, graduate students at the University of Illinois, studied bats from southwest Wisconsin.

L. B. Keith, Department of Wildlife Ecology at Madison, and his associates made numerous contributions on the cycles of hares and lynx. A. W. Schorger, Wildlife Ecology, studied the newspapers and county histories to compile histories of several mammals and birds of Wisconsin, and he made a list of the mammals of Dane County. Since then we have seen quite a lot of ecological work by the Department of Natural Resources (formerly the Wisconsin Department of Conservation) including that of Jim Hale, W. E. Scott, G. J. Knudsen, N. R. Barger, and others. Today there are at least three departments of the DNR directly related to mammalogy, the Bureau of Research, the Bureau of Wildlife Management, and in recent years an important new Bureau of Endangered Resources. One person who may never have visited Wisconsin at all, but who mapped and classified its mammals often, with authority and in a broad scheme of classification was E. Raymond Hall, University of Kansas, my former teacher. In his The Mammals of North America (1959, with K. R. Kelson, and 1981) he summarized the literature including some of his own papers treating Wisconsin specimens, e.g., microtines, weasels, lagomorphs and others, and mapped every species in the state not only for Wisconsin but providing maps of their geographic ranges throughout North America. [I relied on them heavily for the North American maps herein.] Today, in spite of great population growth and intensive land use, Wisconsin still maintains a rich diversity of natural communities under federal and state protection. Since 1971, the state DNR has provided increasing attention to endangered species. Many studies on wild mammals are done cooperatively with state agencies in nearby Upper Michigan, Minnesota, and with the Federal Government. Two national forests (Chequamegon and Nicolet) were established between 1928 and 1933. The DNR established great reserves for wildlife at Horicon, Crex Meadows in Burnett County, the Mead Wildlife Area in central Wisconsin, and in other places. Some

counties have set aside county parks not entirely developed for recreation. Since 1960, The Nature Conservancy has preserved or encouraged the preservation of about 40,000 acres of Wisconsin wilderness. Robbins (1991:32) has mapped the national wildlife refuges, state wildlife areas, and major research stations of the state. There are about 194 scientific areas preserved by legislative action by 1951. Much of this conservation stems from the teaching, eloquent philosophy and sincere efforts of Aldo Leopold and his students. Other important naturalists of the past included John Muir, William T. Hornaday, Ernest Thompson Seton, and even President Theodore Roosevelt, who instilled by eloquent writings in those days a widespread caring for nature. They sparked necessary action to preserve our natural heritage. Some Basic Procedures. In the earliest years American mammals were examined in hand after collecting them with gun or steel trap, or when carried in by native Americans. They were mounted usually in a fierce demeanor, in some sort of natural position, or prepared as a pelt. The skull was often discarded, or the skull might have been left in the stuffed head. Invention of the snap trap, effective for catching small mammals and cheap to manufacture in quantity, led to huge collections of the mice and rats in our museums, with an occasional shrew or ground squirrel. The specially designed museum special trap, which is an expensive trap, strikes the small mammal on the neck or back and seldom crushes the skull. This development, following the technique discovered of using dermestid beetle larvae to thoroughly clean small mammal skulls, led to better skull collections—useful in taxonomic work. “Skin and skull” became the specimen of modern mammalogy, with practices instilled in scientifically trained professionals by the likes of Joseph Grinnell and Spencer Fullerton Baird, and eventually E. Raymond Hall. They all stressed keeping permanent well-written field notes on the ecology of the mammals. Mole traps, pocket gopher traps, and EARLY MAMMALOGY AND NOW

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the Japanese mist net made of fine threads (invisible to flying bats) led to better collections of some heretofore obscure mammals. The use of empty cans sunk into the ground flush with the surface of it, often called a pit trap or can trap, has led to easy collection of shrews (Handley and Kalko, 1993). Drift fences designed to funnel mammals into the traps increase the catch. Once dug in, the cans are easy to check over a period of days or weeks. Today mammal characters also are obtained from blood sera, DNA, isozymes, the post-cranial skeleton and other body parts. Live traps permit marked mammals to be released and re-captured. Small radio transmitters allow some mammals to be followed wherever they wander. Keen observation of animal and habitat always was important, and a fine camera and pair of binoculars are often useful in research. Field collecting has its difficulties because for nocturnal mammals the traps must be set on one day and checked on the morning of the next. Preparation of the specimens, and securing both skins and skulls from loss or damage, take much time and effort. Traps must be set so that mammals will find them, which requires some knowledge (“lore”) about the secretive behavior of the mammal, and of the mammal’s “sign” (e.g., tracks, hairs, runways, burrows and scats). Hall, in Hall and Kelson (1959), and other references describe the steps for making study skins. This procedure is given in Appendix C. Proper state permits must be obtained from state natural resources agencies to collect mammals. These rarely are available for amateurs, and are reserved for professional mammalogists to further scientific investigations. Skins and skulls in personal collections are often illegal. Rare and endangered species are seldom permitted to be collected, and seldom are game animals allowed to be killed out of season unless a rationale is approved. Some natural history museums should be selected for final deposition of specimens, even of carcasses found. Most mammalogical studies would benefit by the preparation of voucher specimens espe-

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cially of rare carcasses obtained for deposition in a museum. Unfortunately, too often the salvaging of specimens does not happen in Wisconsin. Common sense and tact are important for mammalogists, who should not jeopardize their opportunities to study animals by alienating people who object to cruelty and killing of animals. After all, it is in the best interests of the wild animal for workers to know its biology for proper management and its preservation. A policy statement (Acceptable Field Methods in Mammalogy. . . . 1987) of the American Society of Mammalogists has been issued on this subject to all members. The American Society of Mammalogists’ publications Journal of Mammalogy, Mammalian Species, and Special Publications, is an important resource. The annual meetings and constant appraisal of the role in society by mammalogists lead to a respectable and scientific enterprise. The Journal of Wildlife Management, published since 1937, also contains many articles on mammals.

Hartley H. T. Jackson. U. S. Biological Survey, Washington, D. C. Born in Wisconsin, wrote on mammals more than 60 years. 1938.

ENVIRONMENTS AND ECOLOGY OF MAMMALS GENERAL ECOLOGY OF WISCONSIN MAMMALS Prairie, Forest Edge, and Forest From The prairies — ”... My heart swells while the dilated sight takes in the encircling vastness... The clouds sweep over with their shadows and beneath, the surface rolls and fluctuates to the eye... Breezes from the South who toss the golden and the flamelike flowers and pass the prairie hawk that, poised on high, flaps his wings, yet moves not. From Entrance to a Wood — “Enter this wild wood and view the haunts of nature. The calm shade shall bring a kindred calm, and the sweet breeze that makes the green leaves dance... of green and stirring branches alive and musical with birds... The squirrel, with raised paws and form erect, chirps merrily. Throngs of insects in the shade dance in the warm beam that waked them into life... Even the green trees partake as they bend to the soft winds, the sun from the blue sky... From Forest Hymn — “All these fair ranks of trees. They, in thy sun, budded and shook their green leaves in thy breeze, and shot toward heaven... When I think of the great miracle that still goes on, in silence around me — the perpetual work of thy creation, finished, yet renewed forever.” — William Cullen Bryant.

The southern prairie soils, rich in organic matter, support dense grass and forbs; the friable and well-drained soils shelter numerous burrowing mammals, especially seed, grass and insect eaters. The extensive and often continuous northern and eastern forests of Wisconsin provide mast crops, tree canopies useful to arboreal mammals, nest cavities and loose bark for their homes, and correlated ecological factors such as less snow cover, more leaf litter and less wind chill. The southern hardwoods provide mast and cover, and in the clearings the forest edge mammals thrive. Rivers and lakes are homes for many semi-aquatic mammals, as are the vast swamps and countless marshes of Wisconsin.

These wetlands provide homes, feeding and breeding areas to many kinds, such as jumping mice, shrews, bog lemmings, beavers, muskrats, mink, and otters. Great rivers (see section on zoogeography) restrict some mammals mostly from dispersing eastward, but the sandy floodplains were routes of dispersal for the pocket gopher. Rocky bluffs with caves and mines provide shelter for millions of bats. Basically, the chief contingents of mammals are boreal, i.e., northern (e.g., northern flying squirrel, Canada lynx, moose) and southern (e.g., prairie (= eastern) mole, least shrew, opossum). Boreal species have occupied the North Woods for centuries, and have dispersed southward even somewhat beyond the limits of present day boreal forests. Southern invaders from the deciduous woodlands, forest edge, and prairies in the south have moved northward into the northern forests. By way of sand dunes and beaches, wetlands, wet prairies, and savannas the dense, shady forests were penetrated by many sun-loving prairie and forest-edge mammals. This invasion occurred even before Europeans and Americans arrived. After human settlement, the clearing of forests by farmers and lumbermen and tree removal for road rights-ofway encouraged the northward dispersion of southern species. But at the same time numerous boreal species, and some grassland kinds such as the least shrew (Cryptotis parva), were disappearing probably because of agricultural practices. Chemicals used in the environment may have decimated and eradicated local populations of some mammals. Until there was sensible management of game animals and furbearers, some mammals were eradicated by unregulated hunting and trapping. A few such species have been reintroduced. Habitat destruction and agricultural practices in Wisconsin are the greatest threats to Wisconsin mammals today, although the latter is often beneficial to animals that need openings and forest edge. There are many positive things that should be emphasized regarding wild mammal conENVIRONMENTS AND ECOLOGY OF MAMMALS

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servation in Wisconsin, and the preservation of mammal environments (many by hunters and for hunting). Reintroductions of some lost species, protection of wilderness areas, acquisition of new refuges, scientific management of harvested mammals, and protection by the rare and endangered species programs have been remarkably successful, to name only a few programs. These are primarily the responsibilities of the Wisconsin Department of Natural Resources. But recent losses from our fauna of some species without notice, the dramatic decline of others, and the relentless assault on natural habitats by urban sprawl, highway development, and many farmers and builders (in both city and country) should not be allowed to cause further losses of any mammals from our fauna. Even counties and individuals must get into the conservation effort. No resting on the laurels of past successes is sensible. Much proposed land use today is detrimental to nature, and many political maneuvers nationally and at local levels seem to be intensifying environmental change as so-called “progress”. In the popular rationale of profit and jobs, even a protected nature preserve seems for some people merely a reserve. I am advised that at our state level, large area land use planning, comprehensive land management, and ecosystem management present a sound approach and method for accomplishing the goals of genuine conservation. They are all based upon the science of ecology. Updating ecological information from Jackson’s treatise (1961) on mammals is necessary particularly in comparing the concepts of his day to those of modern ecology. The fundamental concept in Jackson’s work is the singular effect of temperature roughly dividing Wisconsin into three faunal subdivisions, namely three of C. Hart Merriam’s life-zones. Jackson’s perception of temperature was inadequate and in some places inaccurate. Furthermore, the life-zone concept does not work well except in mountainous regions of western America. Neither latitude nor elevation relates

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much to temperature in central Wisconsin. I suppose Rib Mountain may be even warmer in summer on its high crest than downhill by the Rib River. Central Wisconsin shows more effects of wind chill and deep frost than do northern habitats near Lake Superior. Much greater ecological importance than temperature effects should be attributed to the geomorphology of this state, the major plant communities that developed after the recession of glaciation, the effects of ecological succession and land use, and the zoogeographical interactions of invading and retreating mammals.

FORMER GLACIATIONS The Pleistocene Epoch, popularly called the Ice Ages, consisted of four continental glaciations extending as far southward on the North American continent as central Iowa and northeastern Kansas. The epoch lasted about 2 million years, and the climate created most of our landforms and soils over vast regions (Dorr and Eschman 1971). The glacial stages were not simple advances followed by melting and recession, but were often complex, consisting of two or more advances with various side lobes from the glaciers. Low hills comprised of glacial sediments (called drift) were deposited by the ice fronts and are identified as lateral or terminal moraines. They mark the extent of the advances of ice. The moraines can be dated (i.e., aged). Interspersed with the four cold glacial periods were three interglacial periods comparable to our present day climate. Although the southwestern hills of Wisconsin were bypassed by glaciers repeatedly (giving basis for the name “Driftless Area”), the climate was doubtless frigid during the glaciations. Where forests subsisted at all, they were mostly spruce, and the mammals in them were boreal. On the snowfields and ice, the mammals were like those in the Arctic. Glaciation scoured much of the Wisconsin terrain during the Pleistocene Epoch end-

ing about l0,000 years ago. Just preceding the end of Pleistocene glaciation, late in the Wisconsin glaciation, a huge glacier sprawled across the northland, lay in the Lake Michigan basin, and extended westward across the valley of the present day Fox River (Long 1974). Earlier glaciations had already planed much of what is now southern Wisconsin. Except for the non-glaciated Driftless Area in southwest Wisconsin and scattered exposed outcrops of rock, the terrain today features post-glacial phenomena of either the Wisconsinan or earlier glaciations. Glacial processes affected geomorphology almost everywhere. Two subsequent processes, of course, have been at work: (1) stream erosion, and (2) soil formation. The vast glacial outwash sands and sands eroded from a sandstone bedrock in central Wisconsin may lead to deep frosts there in winter and relate to extreme summer heat and drought. Large elongate and interconnected glacial moraines extend across the state. These hills are usually covered with woods. Sands, boulders and clays, with acid soils, are prevalent. Lying southward of the Wisconsin glaciers, in what is now Illinois and southern Wisconsin, the flat country scoured by earlier glaciation was left to nature. The prairies that developed there had deep, black topsoil, rich in organic material. This has been largely put to the plow in historic times, but here and there prairie remnants and old field habitats have allowed most of the prairie species of our Wisconsin mammals to survive in spite of farming. A huge lake called Glacial Lake Wisconsin drained from the terminal moraine near Stevens Point southwestward. It exists even today as marshes, flowages and drained marshes from the Buena Vista in Portage County to the enormous Pettenwell Flowage, extending southwest toward the Driftless Area of the hilly and rugged Coulee Country in southwestern Wisconsin. Over most of the state is a thin wind blown glacial loess intermixed with forest humus and soils derived from the underlying bedrock.

CLIMATE The climate is relatively uniform today in Wisconsin, in average temperature, winter and summer temperature, and precipitation (Table Env-1). The warm air of summer pushes northward from the south, and it is warmer in the southern and central counties with more hot days. Winter or summer, the cold air masses originate in the Canadian Arctic regions and usually swing eastward from Minnesota or flow across Upper Michigan and southward along Lake Michigan. Prevailing westerlies bring moisture eastward, usually from Minnesota. There is a mingling of cool Arctic air and southern warm air. As a consequence from temperature and atmospheric pressure changes, precipitation increases eastward, and the eastern forests have higher humidity. The temperature gradients change regularly and gradually north to south, as does photoperiod (= day length) and snow cover (with exceptions). The great freshwater lakes Superior and Michigan moderate climates near the shores causing the seasons there to lag. The growing season (100 days in the north, 170 days in the south), based on frostfree days, is variable in Wisconsin. Though roughly related to latitude, the season varies from one city to another (Moran and Morgan, 1976), and the extreme numbers are variable and not always as expected. Frost

Table Env-1. Climatic Factors of Southern and Northern Wisconsin (After Curtis, 1959), generally prairie and forest. Prairie // Deciduous Forest January mean temp* July mean temp Annual mean Growing season* Annual precipitation Annual total snowfall* Number days 0 precip* Ave. evaporation (July)* Warm, days above 68 0F*

15.1 degrees F // 11.40 F 71.1 // 68.0 44.6 // 41.5 148 days // 126 days 31.5 // 30.1 in. 41 in. // 5l in. 90 days // .05 days 5-6 in //3-5 in 60-90 days // 0-60 days

*Apparently significant to mammalian distribution. ENVIRONMENTS AND ECOLOGY OF MAMMALS

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penetration of the ground is a variable phenomenon from place to place in Wisconsin, as is the effect in some places of summer drought. Both of these seem most severe to the small mammals on the sandy soils, especially of central Wisconsin. Greater snowfall in Upper Michigan and northern Wisconsin limits frost penetration there, thereby diminishing frost-caused mortality of small mammals. Snow cover affects distribution, favoring mammals such as deer that move into the deep coniferous woods, and hares and lynx, which run easily over the snow. Some temperature data are mapped herein (see accompanying Fig.). Slight differences in mean temperature throughout Wisconsin do not sharply influence mammal distributions. Rocky outcrops, humuscovered forest soils, sun dappled prairie sod and bare sands, shaded barren woodland soils, riparian vegetation and wet soils, and other innumerable local factors provide a diversity of mean temperatures. These allow an intermingling of boreal and southern species across the middle of Wisconsin, a grouping that helps define the “Tension-Zone.”

Winter Severity (includes temperature). Mild to 50, Moderate, over 50 is Severe. 1961-90. Bartelt et al. Compare Vernon and Marinette.

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At dawn of a new millennium there is great concern that the climate is steadily warming, due to so-called “greenhouse effects” of atmospheric pollution, El Nino ocean effects, and other causes. So far it seems difficult to confirm such a trend, but one notes the past eight or ten winters have been mild, especially 19992006 (but 2000-2001 was colder). Record high winter temperatures for three years relate to the waters of Lake Michigan that receded significantly (although U.S. Army engineers dredged out its outlet eastward). Nationally there are severe droughts and shortages of water; and there seem probable effects on wildlife (e.g., increasing deer densities).

PHYSIOGRAPHY To better understand the ecological role of physiography, often called geomorphology, will reveal interesting and paradoxical effects in Wisconsin. In this author’s experience, in the rugged mountain-basin topography of the Rockies, and even in the flat cuestas of Kansas, there is a correlation of natural effects of temperature, climate, vegetation, and animal distribution, all relating to the basic land forms. In Wisconsin, the provinces mapped by Martin (1932) in his classic works derive almost entirely from the single source of underlying bedrock. Indeed, both non-glaciation (in the rugged Driftless area of southwest Wisconsin and as well in the vast swampy marshlands southwest of Wisconsin Rapids) and Pleistocene glaciation have subtly affected the Wisconsin landscape. They have drastically modified the land of granitic rocks of northern Wisconsin showing an almost recent effect (youthful stream development, marshes, lakes). On the Central Plain vast deposits of sand and subsequent sandy soils (drained out of glaciers) are found. The igneous bedrock in the north and the underlying sandstone in the center primarily create the different physiography. Perhaps the mammals that range through several provinces only follow certain plant communities,

and since the land is not tremendously varied in elevation the pervasisive factor of physiography seems less important than in other states. In 1932, Martin described the physiography, or geomorphology, of Wisconsin as five provinces. 1. Lake Superior Lowland: The good soils there are underlain with ancient pre-Cambrian rocks of igneous and metamorphic structure, and lie approximately in the basin of Lake Superior. 2. Northern Highland: This province consists of most of boreal Wisconsin, and contains swamps, lakes, marshes, and shallow streams of youthful drainages since the retreat of the Wisconsinan glaciation. Here are found boreal forests, probably held over from the climate of the late Wisconsin. This land was not planed off by glaciers as is often thought, but is an old peneplain of a great, worn-down mountain range, with its hard bedrock foundation submerged in seas, but re-emerged from them about 200,000,000 years ago. Nevertheless, the peneplane was often scoured and planed by Pleistocene glaciers from several sources. 3. Central Plain: This consists of sands and savannas with extremes of heat, drought and frost, but also includes the unglaciated swampy, marshy areas southwest of the edge of the Wisconsin ice sheet. This entire region of some 13,000 mi2 of generally infertile soils (but blessed by irrigation and now becoming useful for peat and cranberries) is entirely underlain by Cambrian sandstones that border the northern igneous bedrock northward and several sandstones and limestone bedrocks eastward, and southward. 4. Western Uplands: These are largely prairies or savanna regions, including important river terraces and lakes of the Mississippi River, and the presence of other deep rivers (Black, Chippewa, St. Croix, and the lower reaches of the Wisconsin). Rugged bluffs of sandstone and limestone are found in this region important to cave-dwelling bats, but the elevation of these hills is not high.

5. Eastern Ridges and Lowlands: This region is associated with good soils, flat terrain and cuestas with limestone and shale bedrock including a higher, more rugged outcropping of the Niagara Formation lying eastward along Lake Michigan. All of these physiographical provinces relate somewhat to the distribution of mammals, except that the mammals range freely through one to another depending on the prevailing vegetation and their mobility. For example, moose and lynx enter Wisconsin in the Lake Superior Lowland, but both species range southward and eastward in the boreal forests of the Northern Highland, and some boreal mammals range even into the swamps near Necedah, the hills of the Baraboo Range, or the forests along Lake Michigan. There are Western Upland prairies more or less connected ranging from the low Mississippi Valley and grassy western “goat prairies” on the unforested ridges, through the openings in the savannas of the Central Plain. These rolling grasslands become intermixed with hardwood forest, creating much forest edge and savanna, extending along the Wisconsin River’s southern boundary. There the proximity to the Grand Prairies Province of Illinois and rich soils dating from the early glaciations allow the free dispersion and deep penetration of prairie flora and fauna into Wisconsin. To the five physiographic provinces I add two important geological features: Wetlands and Islands. Islands. There are numerous islands today clustered in Lake Michigan (e.g., Big Summer, St. Martin, Rock and Washington) and Lake Superior (e.g., the Apostle Islands: Madeleine, Outer, and others). Both areas were glaciated perhaps even 10,000 years ago, so that only in protected places could mammals have survived there. Probably these mammals were boreal (see Pre-historic Mammals). Today the waters are cold and rough, so that rafting on floating logs and branches is uncommon, and hibernators, inactive in winter, cannot cross the winter ice. Therefore, many mammals cannot invade these ENVIRONMENTS AND ECOLOGY OF MAMMALS

35

isles, but if somehow established there those species were isolated on the isles. This has led to some interesting evolution, even in a brief 10,000 years (geologically speaking). Two races have been named from the Door Peninsula, a chipmunk Tamias striatus doorsiensis and a bog lemming Synaptomys cooperi jesseni. No significant speciation has been observed on the more recently uncovered Apostle Islands. Deer mice show microgeographic variation on both island groups. Bats and aquatic mammals easily traverse the water barriers, and carnivores readily cross either water or ice. Humans have introduced some species to some isles (Long 1978c; Long and Long, 1993). Islands are discussed more fully in the section on Zoogeography. Wetlands. Neither forest nor prairie can establish itself well when conditions are too wet. The “wetlands ecosystem”, if extensive enough, consists of a mosaic of variable microhabitats in association with semi-aquatic and somewhat aquatic mammals. Recently and suddenly, Wisconsin wetlands have come to the fore, and have been popularly protected. Mammalogists must study them. Bats, raccoons, voles, and the semi-aquatic muskrat are found in most of them, and Blarina, deer mice, jumping mice, red-backed voles, tree squirrels and chipmunks inhabit copses of trees and shrubby areas at many wet localities. The wetlands differ in their vegetation, water quality, and wildlife. Generally, the greater the amount of vegetation, the more mammals are found. Some wetlands, such as Shorelines and Sand beaches rarely provide habitat for mammals, but even sand dunes, with scattered vegetation of peculiar and regular beach-dune flora, shelter an occasional white-footed mouse and local populations of the prairie deer mouse Peromyscus maniculatus bairdii. Beaches of lake-pebbles and gravel are visited by mammals from shrews to bears, but have no known permanent residents, occasionally housing a lodge of beavers. Tamarack, cedar, spruce, and alder swamps and bogs contain Arctic and masked

36


shrews, snowshoe hares, red-backed voles, meadow voles, bog lemmings, weasels, whitetailed deer, and even an occasional bobcat, Canada lynx, or moose. Open marshland with wet soils near standing water containing plants such as swamp loosestrife, royal fern, blue vervain, sedges, rushes, grasses, and such shrubs as red-osier, dogwoods, willows, Spiraea, and aspens have mammals including red foxes, coyotes, weasels, meadow voles, jumping mice, occasional bog lemmings, Franklin’s ground squirrels, mink, and otters. Cattail marsh is an important habitat for masked shrews (Sorex cinereus), muskrats, jumping mice (Zapus hudsonius), Franklin’s ground squirrels, mink, and otters. Southern fens, as described for Wisconsin by John Curtis, with alkaline water, generally contain a few mammals, such as the Southern bog lemming, and, nearby on the brushy shores, white-footed mice. Red squirrels (Tamiasciurus hudsonicus), gray squirrels (Sciurus carolinensis) or flying squirrels (Glaucomys volans) may inhabit the nearby trees. Riparian streamsides provide important habitat and streamside corridors for many kinds of mammals. Wet meadows, with sweet flag, milkweed, golden rod, sedges, bulrushes, marsh marigold, and transitional plants stand between forest and aquatic habitats, so that the mammal fauna is rich, varied, and usually seral.

SOILS The topography, about 1,000 feet (= 305 m) elevation overall, may lack dramatic relief, but there are several outstanding features of the terrain apart from the vegetation on it. The non-glaciated hilly southwestern part (the coulee country, meaning valley country) is a rugged region with high wooded slopes and numerous crevices, ravines and caves. The sand plain in the center of Wisconsin, although heavily wooded and penetrated by streams and rivers, is an important geological feature due to such vast deposits of sand. The lakes

and marshes that dot the North Woods constitute a vast wetland-boreal wilderness still not much cleared by human hands. The pale soils and outcrops of the Niagara Rock Formation on the Door Peninsula and isles offshore, as well as the isolation and semi-isolation of mammal populations there, comprise a highly interesting laboratory of recent evolutionary processes. Outcrops of bedrock, such as granite or limestone, the post-glacial soils and till, sandy outwash deposits, river bottoms, peatlands and sandy loam prairies are diverse habitats necessary for particular mammals in Wisconsin. Most of the soils are acidic, often infertile, and range from very dry to very wet. They are classified as follows: 1. Coarse, bouldery acid soils derived of igneous and metamorphic rocks of the Northern Highland (see above). 2. Acidic and infertile sands from sandstones and glacial outwash. 3. Fine-grained alkaline soils derived mostly from dolomite (limestone). The former glaciers produced clay, sand, gravels, silt and indirectly (with accumulated mossy vegetation) deposits of peat. Reddish lake clays and sandy loams were produced, mostly in eastern Wisconsin along Lake Michigan and Lake Winnebago, but also along the Lake Superior shore. Sands were deposited up to 60 feet (18.3 m) depth on the Central Plain, and are widespread across six or seven counties (a broad band often exceeding 100 miles (= 161 km) width). Another band of sand extends along the St. Croix River northeast to nearly as far north as Bayfield. A deep (up to 16 feet), so-called silty loess lies along the Mississippi River in southwest Wisconsin. Loess is also found in Dane and several adjoining counties (Zimmerman, 1991). A quick overview (Hole et al., 1966) of Wisconsin soils, named generally from geographic names, mentions some clayey soils concentrated along the shores of the Great Lakes (Hibbing, Ontonagan soils near Lake Superior; Manawa and Kewaunee soils near

Lake Michigan). Most of northern Wisconsin is overlain with poor acid soils on the uplands (Iron River, Kennan soils) and reddish brown sandy soils on flat and rolling terrain (Omega and Vilas soils). These may cover the granitic and basaltic Cambrian rocks. In the south are rich sandy loams (Fayette, Dubuque, Wea, Warsaw, Dodge, McHenry, and Casco soils). These prairie soils merge northward into poorer sandy soils based on sandstones and siltstones in the west (Hixton, Norden, Sparta soils) and on glacial outwash sands in the center (Plainfield, Oshtemo soils). The Fox and Wolf river valleys are limey and sandy soils overlying drift and limestone strata, which often are conspicuous outcrops and bluffs in Door County. A surprisingly large total area in Wisconsin consists of low, flooded soils (Elba, Poygan, Newton, and Arenzille) comprised of peat and muck (e.g., Houghton soil). The prairie mammals, such as Spermophilus tridecemlineatus and Peromyscus m. bairdii, both of grassland and scattered brushy copses, inhabit the southern loams and range onto many accessible open sandy soils northward. The boreal mammals, such as Clethrionomys gapperi, Glaucomys sabrinus, and Myotis lucifugus occupy mainly the forested gravels and coarse, sandy acidic soils derived of igneous and metamorphic rocks. They make up much of the terrain of the northern counties. Aquatic and marsh-dwelling mammals thrive on the low, flooded soils in peat bogs and other wetland communities. Outcrops of limestone (dolomite), granite, and rough country generally, are habitats of mammals such as chipmunks and long-tailed deer mice. Both large and small caves in the sandstone or limestone outcrops and river bluffs in southwestern and western Wisconsin are homes to thousands of bats. There may be remarkable differences between the humus and topsoil of deciduous forest and coniferous forest stands. Pine needles cause soils to be remarkably acidic. Deciduous leaves produce a deep leaf litter with less acidity. Grasslands have more alkaline soils that ENVIRONMENTS AND ECOLOGY OF MAMMALS

37

Table Env-2. Env-2 Some mammals and their soils, listed generally from north to south, and important beach dunes from Door County.

1. Valders’ Clay and Loams including coarse northern soils and some extending along Lake Michigan: Boreal species, such as snowshoe hare Lepus americanus, red-backed vole Clethrionomys, and star-nosed mole Condylura cristata dwell there. 2. Northwest sands: pocket gopher Geomys, white-footed mouse Peromyscus leucopus 3. Peaty soils: Shrews, Condylura,Woodland jumping mouse Napaeozapus, southern bog lemming Synaptomys, muskrat Ondatra, and ermine Mustela erminea. 4. Central Sands: P. leucopus, eastern cottontail Sylvilagus, prairie vole P. ochrogaster minor. 5. Prairies, light loess about four feet deep more or less: Scalopus aquaticus, Cryptotis parva, Reithrodontomys megalotis, Spermophilus, P. m.bairdii, Taxidea taxus. 6. Beach Dunes: P. maniculatus bairdii 7. Thin loess or forest topsoil of only a few inches depth where the other soils are not exposed: Includes many mammals of prairie and forest lands.

Including Three Wisconsin Biomes (grand communities) of North America. V. Shelford (U.Illinois Press).

38


encourage dense root development even when dry; the result is called sod. In winter the entire prairie generally freezes and loses all green leaves and grasses, which must be renewed in the coming growing season. Herbivores and, indirectly, insectivores or carnivores are affected by this seasonal effect.

COMMUNITIES Three Grand Floral Communities. In the simple binary subdivision of the Wisconsin environments, the so-called “North Woods”, consisting of a boreal woodlands biome (deciduous, coniferous, and mixed forests) is northward, and the prairies intermixed with deciduous woods on the one hand, and on the other, many open agricultural fields and old fields, bottomlands, boreal remnants, local fens, bogs, and large marshes lie in the south. Open prairies are extensive grasslands; they not only look like great rippling seas, but are as adverse as seas to some mammals, while to others are essential. Woodland forms include eastern chipmunk, southern flying squirrel, and others. Prairie mammals include grazers, formerly including Bison, and numerous burrowers such as the prairie mole Scalopus, ground squirrels Spermophilus, and the prairie deer mouse, P. m. bairdii. Therefore, southern mammals seem divided as prairie and deciduous woodland species. Zimmermann (1991) in “Wisconsin Birdlife” discusses how three important floral areas meet in central Wisconsin: the boreal North Woods (mixed and conifer forest); in the southwest and south-central, the extensive dry prairies (intermixed with maple, basswood, prickly ash, and oak on the rugged highlands in the coulee country); and in the southeast part of the state extensive broadleafed forests (beech, hardwoods). In Jones and Birney (1988) these same regions are termed: “hemlock-white pine-northern hardwoods” which in Wisconsin studies also have been called conifers and mixed woodlands; in

the southwest, known in Wisconsin more often as the Driftless Area or the Prairie-woodlands, are many interconnected prairies and extensive stands of “maple-basswood”; in southeast Wisconsin are deciduous “Oak-hickory forest” and “Beech-Maple” forest. Curtis (1959) has written a classic study of plant communities of Wisconsin. Stearns and Kobriger (1975) extended this descriptive study for the watershed of Lake Michigan. The analysis of the occurrence of mammals in these plant communities facilitates understanding of certain ecological relationships (Table Env-2). Some extirpated and abundant mammals are not included in this survey. Lying along the Wisconsin moraine is an ecotone separating communities generally into northern (N) and southern (S) groupings. N1. Cat-tail or Reed Marsh // S1. Cattail or Reed Marsh N2. Northern Sedge Meadow // S2. Southern Sedge Meadow N3. Alder Swamp // S3. Shrub Carr (willow, dogwood) N4. Northern Lowland Forest (tamarack and black spruce) and Relic Bogs // S4. Southern Lowland Forest (maples) N5. Northern Wet Mesic Forest (white cedar) // S5. Southern Wet-Mesic Forest (American elm) N6. Northern Mesic Forest (sugar maple) // S6. Southern Mesic Forest (maples) N7. Northern Dry Mesic Forest (white pine) // S7. Southern Dry Mesic Forest (red oak) N8. Northern Dry Forest (jack and red pines) // S8. Southern Dry Forest (black oak) N9. Jack Pine Barrens // S9. Xeric Dry Prairie (sunflowers, bluestems) N10. Birch-Aspen Forest // S10. Mesic Prairie (legumes, luxuriant grassland) N 11. Boreal Forest (spruce-fir) // S 11. Oak Opening [savanna] (white and pin oak). Nearly twice as many uncommon mammal species occur in the northern communities as in southern ones. These include the

boreal kinds and recent southern invaders. There is much ecological diversity in forest lands. Most northern communities are well represented by mammals, except Dry Mesic Forest and Dry Forest. The most depauperate is the Jack Pine Barrens. These have poor soils. Birch-Aspen Forest is not quite so well represented with species as are the remaining northern communities. The southern communities are not strongly represented by mammals, except Oak Savanna, followed by Mesic and Dry Mesic Forest. There is much intermingling of habitats, even merging communities of the three major biomes. For example, in central Wisconsin, where I have lived 40 years, there is a great deal of local plant diversity (spruce, hemlock, white pine, sugar maple, red maple, butternut, pin and bur oak, hickory, cottonwoods, aspens, bluestem as tall or taller than 2 m, basswood, paper birch, cat-tails, marsh grasses, and jack pine in abundance). Likewise, in central Wisconsin there is an amazing, large mixture of mammal species (Long, 1970). By use of average resemblance coefficients to indicate faunal resemblance (of mammals), Long (1970) showed that in central Wisconsin the prairie assemblage of mammals resembles the Dry Forest edge (Oak Savanna) most and the Jack Pine Barrens next. These dry communities are not greatly dissimilar in terms of temperature, precipitation, floras and faunas. They are often combined. The community faunas seem to reflect generally the faunas related to the aforementioned physiographic provinces. Tension Zone. In addition to describing carefully and generally mapping the plant communities of Wisconsin, many of which are essential for the distribution of certain mammals, Curtis (1959) described an ecotone, which he called a “tension zone” extending across Wisconsin like a climatic belt. It is roughly 50-60, as much as 100 miles (= 161 km) wide. There is no clear explanation for this ecotone, except that boreal organisms extend southward to their limits and southENVIRONMENTS AND ECOLOGY OF MAMMALS

39

ern organisms disperse northward into boreal habitats of the north. Temperature plays a subtle role, and in earlier ages it may have played a stricter determining role. The vegetation types are correlated with the presence or absence of animals, northern mammals

with northern vegetation and southern ones with southern vegetation. The vegetation is related to precipitation and soil patterns. Apparently there is some competition between northern mammals and southern invaders coming face-to-face.

Table Env-3. Select animals related to plant communities. Revised Long 1974.

Species

Plant community

Comments

Cryptotis parva Peromyscus maniculatus bairdii Pitymys ochrogaster Taxidea taxus Condylura cristata Sorex palustris Napaeozapus insignis Sorex cinereus Sorex hoyi Sorex arcticus Blarina brevicauda Vulpes vulpes Myotis keenii, M. lucifugus, Eptesicus fuscus Lasionycteris Nycticeius trichopterans Peromyscus leucopus Clethrionomys Microtus pennsylvanicus Pitymys pinetorum Ondatra zibethicus Castor canadensis Sylvilagus Lepus americanus Canis latrans Canis lupus Ursus americanus Tamias s. doorsiensis Eutamias minimus Marmota monax Spermophilus franklinii Lontra canadensis Lynx canadensis Tamiasciurus Glaucomys sabrinus Synaptomys cooperi Erethizon Urocyon Neovison vison Odocoileus Mustela frenata M. erminea M. nivalis

S9-S11 ditto ditto ditto + S2, N2, N9 N1-N6, N10-N11 ditto ditto ditto+S1-S5, S10 N1-N11, S1-S8, S11 N1-N4 ditto ditto Wide-spread ditto ditto wide-spread SE Wisconsin ditto N1-N6 ditto 6, S6,S7 ditto ditto ditto N1-N5, N11, ?N6 ditto + S1-S11 N1-N11, formerly S1-S8, S11 remote ditto Open woodlands N1-N6, N8-10 N6-N8, S6,S9, S11 N1,N2,S1,S2, S10 N1-N6, N10, N11 N1-N11 N4-N11 N5-N10 N6-N8, N11, S10, S1-S6 N1-N11, S1-S8,S11 N4-N9, S4-S8,Sll ditto ditto Usually N5-N8, S5-S8,S11 N1-N5,?N11, S1,S3,S10 N1-N2, S10,S11

Sandy loam, rare ditto ditto ditto Wet, mesic ditto, brooks, marsh ditto ditto wet, dry, disturbed, water. Marsh, alders, Canary grass Most habitats ditto Needs hibernacula ditto ditto Forests, needs trichopterans, beetles, etc. Ash, silver maple, oak Woods, brush Woodlands Wet, mesic grasses Leaf humus, clay soils usually Wet, mesic ditto Brush Wet, mesic, winter snow cover Ubiquitous

40


Mast, remote Open woodlands, rock outcrops, range retreating Open woods, forest edge Wet, mesic Wet, protection Forest, mesic, hares, winter snow cover Forest, savanna Mast, tree cavities Grasses, sedges, black soils, boulders Northwoods, tree canopies Brush, rock outcrops Wet, mesic Most habitats Mesic Wet, mesic, snow cover Rare

MICROHABITATS “Microhabitat” refers to one subdivision “preferred” by a species above others within a larger habitat. The word focuses on an organism’s specific and localized environment, particularly the physical parameters. Microhabitat differs from “niche”, which is an organism’s function in an ecosystem. Not only have few microhabitats and their microclimates been studied in Wisconsin, even the nests of some obscure mammals have never been found or described. Heat and water availability play an unknown role for mammals in Wisconsin’s local habitats; but water metabolism is important in lactation, kidney function and heat loss. Summer drought and heat, inseparable problems, may become lethal and profound in the general effect, but probably it is especially so, spottily and sporadically important in variable microhabitats. I have observed chipmunks basking in the morning sun on rocks that heat up to 50o C on a summer day. As important as heat and water are, they are not so dangerous to mammals in Wisconsin as is the bitter winter. Starvation, disease, and hypothermia lead to drastic mortality in exposed species during winter, and even for those sheltered below ground if the frost is deep. However, many mammals are well adapted to winter and do not seem to suffer stress or high mortality. Some that do, seem to recover. The white-footed mouse (Peromyscus leucopus) suffers terrible mortality in some winters in central Wisconsin, but it is the commonest mouse. Some mammals hibernate such as ground squirrels (Spermophilus), woodchucks (Marmota), and jumping mice (Zapus and Napaeozapus); some cache food to last through the winter such as the short-tailed shrews (Blarina brevicauda), both chipmunks, tree squirrels, the pocket gopher, beaver, and some mice (Peromyscus); and some mammals forage below ground to eat roots and insects. Some mammals den up and slow their metabolic rates, whereas others forage actively

above or below the surface of snow. One can well imagine a diversity of microhabitats for all these kinds, which have one common protection, a den or nest with a moderate microclimate below ground and out of the wind. To conserve body energy, mammals may use burrows (badger, moles, and pocket gopher), lodges (beaver and muskrat), tunnels under the snow (shrews, mice, and weasels), or caves (bats and occasionally other mammals) to provide more moderate environments. Even wolves and deer seek dense woods and shrubs, out of the wind, and lie partially buried with snow (Ozoga, 1968; Mech, 1970). Many mammals drag insulating materials into the den (bears, weasels, voles) or plug the openings to provide additional insulation (badger, pocket gopher, ground squirrel), or dig down below the frost line (moles). Some huddle together to conserve heat locally (e.g., pine voles, southern flying squirrel, the rare Indiana bat, and occasionally striped skunks, raccoons, even porcupines). Some mammals allow their gonads to regress and cease breeding (deer mice Peromyscus, pocket gopher, some squirrels). At least three species of bats migrate southward in winter (Lasiurus and Lasionycteris), while thousands of cave bats move into the moderate microclimates of caves or opportunistically into human buildings. Few studies have addressed microclimate in homes of mammals. In a model study of the western ground squirrel (Spermophilus beldingi), Mohrhardt and Gates (1974) provide an example. Getz (1968) showed that microclimatic differences do not separate the redbacked vole and the white-footed mouse, but water use by the former causes it to prefer swamps compared to the drier uplands used by the white-footed mouse. The microclimate has been studied in the winter lodges of beaver (Novak, 1987) and muskrats (Huenecke, Erickson and Marshall, 1958), and in the dens of some large carnivores (Long and Killingley, 1983). Some studies of microclimates have been made in bat caves (Ainsley, 1983; Beer, 1955; Barbour and Davis, 1969). Promising ENVIRONMENTS AND ECOLOGY OF MAMMALS

41

detailed, systematic and technological methodology is suggested by Bakken and Kunz (1988). Whereas caves have been studied, the climate in the hollow trees or rock crevices used by bats has been seldom studied. The effect of the bat, itself, warming its immediate surroundings, and the warmth of the sun have been seldom measured. The nature of the substrate in the hibernaculum or maternity site of bats, differing temperatures at various elevations, the effects of wind currents and humidity, the warmth possible from solar heat, heat from the bats themselves, depth of the cave and distance from the entrance, and other factors all divorce the interplay of variable microclimates from general weather. The temporal and spatial microhabitats theoretically provide opportunities for some “lucky” or opportunistic mammals and disadvantages for others: available foods of insects, shoots, buds, seeds, fruits or mast; or home security of burrows, tree cavities, lodges, dead falls, and dense shrubbery. Relationships also include distance to standing water; relative humidity and snow fall; and open space space to see and escape by running away or scurrying up a tree for safety. All of these vary over the landscape, and from season to season. One opportunistic example is provided by the raccoon, known to use tree cavities and fallen logs for nests (Steuwer, 1943), but which adapts to prairies, savannas and marshes by building ground nests. Another example, the white-tailed deer feeds opportunistically on plant droppings of a porcupine in winter (Shapiro, 1949) or on plants thrown out of a muskrat’s opening on river ice (personal observations). The river current and condition of the stream banks may influence beavers to build lodges or to dig bank burrows; the same dilemma affects nest building for the marshdwelling muskrat, which cannot tunnel where the water table is high. In the American West a mammal may be limited to a mountain, or even a northern slope of a mountain, or to a basin or desert by macroclimate, in a word temperature

42


(Long, 1965, and others). In Wisconsin, the microclimates are influential, especially in open forests. Owing to the layering of plant species, forests provide many more microhabitats and possible niches to specific mammals. This is one of the reasons species richness tends to be high in Wisconsin forestlands. Even the weather cycles of the ages, perhaps from the long ago glaciations to this day, may have evolutionarily fixed some responses and other behavior, of hibernation and migration, to mention but two. We do not yet know the role of long-term microclimatic fluctuations on the Wisconsin mammals. We do not know the long-term interrelationships of organisms within microhabitats, the role of the millipede in the forest, of the sod worms and beetle grubs in the prairies, the role of shrews in the marshes. Lately some conservationists, even the game managers of big game, are beginning to assess the small animals in the managed units. To understand the total environment, the scheme of life, the importance of all members of our communities, and their relationship to humankind, it is essential to study the cryptic and subtle ways of all the mammals and other life forms dwelling in and relating to their microenvironments. Knowledge of microhabitats can be summed up as a paucity.

Table Env-4. Ecological successional seres and selected small mammals in them. Baker, 1983. Mammal

Crop Annual Perennial Shrubs Mature Land Grasses Grasses Saplings HardForbs Forbs wood

Sorex cinereus Blarina

+

+

+

+

+

+

+

+

+

+

+

+

White-footed Mouse +

+

Meadow Vole

+

+

+

Meadow Jumping Mouse Zapus

+

+

+

Prairie Deer mouse

+

+

ECOLOGICAL SUCCESSION

ÀND

Species simply occupy favorable sites as they become available (Table Env-4-5). The dynamic process of succession following ecological disturbance has permitted mammal populations to disperse into developing habitats here or there, while their own habitats changed adversely whence they came. Fire. Aridity and fire helped prairies develop on many post-glacial soils, reducing competition of grassland with developing forests. Although prairie fires are formidable, and I never forget the sight of rabbits and opossums struggling to escape from one, fire probably does not destroy many of the mammals. Mobile kinds may escape the flames and return. Some mammals hide in burrows, but the prairie vole (Pitymys ochrogaster) may be adversely affected (although observed effects resulted from both fire and plowing). Pure prairie stands of grasses and forbs are cleansed of encroaching thickets and trees, and the prairie plants quickly return. In the northern forests, when the weather is dry, fire adversely affects many small mammals. In a three-year study following a

LAND USE

Succession. Habitats change in sequential stages called “seres”. These may take many years to elapse. Some mammals prefer Early stages, relatively brief, whereas others prefer the late (Climax) stages, which may last indefinitely (Table Env-4). Therefore, in good wildlife management the seral stages must be maintained as well as the climax vegetation (i.e., dominant vegetation that lasts). Early successional plants such as the transient blackberries, shrubs, aspens and seemingly insignificant understory and ground vegetation may be more essential to many mammals than the mature trees. Succession and its impact on mammal habitats are illustrated (Table Env-4) for six common small mammals. In Baker’s example, the shrew Blarina was found in all five successional stages. Excluding this shrew, only one mammal (Peromyscus maniculatus bairdii) occurred in the earliest stage, and only three occur in the climax. If succession is staggered the fauna may include six mammals.

Table Env-5. Env-5 Choice of seral and climax communities in north (left) and south Wisconsin. Shade eradicates some mammals.

Mammal

Sorex palustris Lepus americanus Sylvilagus fl. Marmota monax Tamias striatus Tamiasciurus Sciurus niger S. carolinensis Glaucomys volans R. megalotis Peromyscus m. bairdii Peromyscus leucopus Clethrionomys Pitymys ochrogaster Meadow Vole Mustela erminea American Marten White-tail Deer

Shrub carr

Cattail

Sedge Meadow

X X

X X

X X Rare

X X

Dry Pines

X X X X X X

X X

X

X X

X X

X X

Rare

X

X

X

X

Climax Forest

Sand Barrens

Oak Barrens

S. Dry Prairie

X

X X X

X X

X X X

X X

X Rare

X X X

X X X X X X

X X Rare

X Rare

Rare

X X

X

X

Rare

Climax Forest

Rare X X X X X

X

X X

ENVIRONMENTS AND ECOLOGY OF MAMMALS

43

huge forest fire (in the summer of 1976, of 60 square km) in the Seney National Wildlife Refuge of Upper Michigan, Anderson (1982) showed an immediate adverse impact on numerous small mammals. After the fire the most abundant small mammal was the masked shrew (Sorex cinereus) and it was the only species taken in the sedge marshes. By October 1977, the number of small mammals was significantly higher in the burned habitats. Meadow and red-backed voles were abundant, as were chipmunks and other species. By 1980, an abundance of jumping mice (Zapus hudsonius) raised the diversity even higher. Through the succession, deer and black bear seemed unaffected. The fire increased plant diversity, leading to an increase in small mammals. “Edge”, Patchy habitats, Savannas. In ecology, the term “edge” has often been used to describe organisms that dwell at the interface of two distinct habitats. Usually the organism does not survive as well in either of the pure adjoining habitats. There are, of course, many kinds of edge interfaces. In Wisconsin the most common is that between grassland and forest. The woodchuck Marmota is considered an edge species, because it digs a den on an open slope providing visibility, easy digging, and access to plants for succulent foods. Forests may lack all three. Flat fields have poor drainage and less visibility if the vegetation is dense. The woodchuck is often observed on grassy road embankments today, or on open hillsides with nearby woods. Game managers recognize that openings in the forest and old fields increase “edge habitats” which are favorable to deer and some other game animals. Presently there is used in scientific circles the trendy phase, which may last, “habitat fragmentation” or “landscape fragmentation”, suggesting or inferring that as “edge” increases, by whatever means, the pure habitat species are isolated and often lost. This isolation needs much study, for “clear cutting” and worn out fields are becoming commonplace. However, many

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mammals in Wisconsin certainly benefit by the appearance of grassy openings. The whitetailed deer, eastern cottontail (Sylvilagus floridanus) and fisher (Martes pennanti) adapt to them especially well, and cottontails, fox squirrels and woodchucks thrive. White-footed mice and southern flying squirrels may be favored over their northern counterparts. Where fragmentation has created a mosaic of local habitats, the landscape is said to be “patchy” and in scaling and complex patterns of food sources, cover, and distribution of animals, these may exhibit fractal geography. Fractal analysis, a new approach to appraising any complexity that scales down and elaborates as it scales, may increase understanding of such elaborate patterns. The savanna community is open grassy habitat with little continuous tree canopy. The scattered, mature trees are usually oak, in some places jack pines, or various kinds of thickets. If the shrubby thickets are not continuous, interfaces in the savannas may be “edge” for numerous species of animals. The openings made by humans (such as railroad or roadside rights-of-way, fields, lumber camps) in forests may qualify as savannas, and are often grown to weedy vegetation. Good examples of savanna mammals are eastern cottontails Sylvilagus, ground squirrels Spermophilus, white-footed mice P. leucopus, the prairie vole Pitymys ochrogaster, and probably in western Wisconsin even the western populations of P. pinetorum. Forest Openings. Our northern forests are closing their grassy openings by ecological succession, especially on loamy soils. Thus, succession causes deterioration of summer range for many mammals. Usually 3-5 percent of forest land maintained as open grassy range would be of benefit to deer and other wildlife (McCaffery and Creed, 1969). Openings can be preserved easier than created. Since the Wisconsinan glaciation, forest openings created by frequent natural forest fires have been extensive. Most of northern Wisconsin was forested by mature timber with lit-

tle undergrowth, but vast areas of barrens and burns were commonplace. Savanna-like shrub lands and pine barrens were widespread in the northern forests. However, wet forests may show little effect of fire. On the Upper Peninsula a popular description is “asbestos forest.” Today most forest openings are less than 10 acres in size and result from land use. Invading weedy species may thrive in such openings. Bracken grasslands and treeless exposures on sandy soil result from timber cutting and fires. Many meadows on the heavier soils resulted from logging camps, pastures, and failed farms. Plants present on loams include Agropyron, Poa, Cirsium, Rubus, and Achillea. On medium soils today plants such as Poa, Hieracium, Agropyron, and Fragaria occur. On sand soils Hiracium, Myrica, Vaccinium, and Poa are found. Other studies show Pteridium, Myrica, Carex and Gaultheria on bracken grasslands. These openings improve summer range for white-tailed deer and provide habitat for a variety of small mammals such as voles and shrews, and carnivores preying on them. In the southern grasslands, and in the pine barrens on thin soils are conspicuous assemblages of prairie plants. Notable are Andropogon, Liatris, Amorpha, Artemisia, Aster, and Carex. Such plant communities allow free dispersion of prairie mammals into the northern forests, and cause the strong affinities of prairie assemblages of mammals with those of the pine barrens and forest edge. Land Use. Land use such as clearing dense forests, plowing fields and leaving some fields fallow, mowing rights-of-way along railroads and roads, and lawns in urban areas, has allowed the recent invasion of many southern species into the North Woods and up the Door Peninsula. By the middle of the 20th century, some southern species (e.g., Spermophilus tridecemlineatus, Glaucomys volans, Peromyscus leucopus, Peromyscus maniculatus bairdii, and Sylvilagus floridanus) had found their way through open woodlands, wetlands and along Lake Michigan dunes and beaches

northward in Wisconsin as far as Marinette County, Michigan (Burt, 1948). Today that movement northward is accelerated, and some boreal forms such as the northern flying squirrel (Glaucomys sabrinus), the least chipmunk (Eutamias minimus), and the forest deermouse (P. m. maniculatus) may suffer because of competition. Water shrews and some jumping mice, and perhaps other mammals, may also be losing habitats due to land practices and water pollution. Forest and wetland preservation, if it continues in Wisconsin, may help save many of these mammals. Excellent maps of former vegetation and the present day pattern of agricultural and urban regions are given in a recent Wisconsin report (Anon. 1995, see maps). Roadsides and railroad rights-of-way not only are grassy openings in forest, but they provide linear (traversed faster) routes of dispersion. Many mammals (e.g., voles, deer mice, probably others) expand their range following these routes, and some (e.g., Marmota monax) build up their highest densities in such habitats (Woodward, 1990). The slaughter of mammals from mice to deer, including opossums, raccoons, skunks and thirteen-lined ground squirrels, by automobiles is excessive mortality. To manage rare mammals such as wolves along paved roads such as Highway 53, in northwest Wisconsin, is a primary cause of concern. The Dairy Farm in Wisconsin, one of America’s most unappreciated treasures, was an almost biblical provision of wildlife habitat. Dairy farms are found throughout Wisconsin. A typical dairy farm may have woodland, open fields and edge communities. The edge and woodland provide wildlife over many years. Many farms failed, and their worn out soils lie fallow. Prairie-like grasslands, thickets, and forest may develop from the old-field habitats. Lumbering nearly devastated Wisconsin’s northern forests early in the past century, and removed many of our finest trees throughout the state. Clear cutting in strips today is a controversial practice that hurts some organENVIRONMENTS AND ECOLOGY OF MAMMALS

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isms and benefits others; the harvest of old timber does the same thing. Replanting of the forests and conservation by both private, state, and even county agencies have led to forest renewal and continuous use of some trees for paper and lumber. Forestry was decidedly beneficial to most Wisconsin forest and forest-edge mammals. Urban mammals. In cities and suburban areas, besides the introduced Norway rats and house mice, and unwanted or free-ranging domestic cats, there are today numerous deer, raccoons, cottontails, big brown bats, chipmunks, cottontails, gray squirrels, voles, opossums and occasionally other species that thrive in our midst. Besides the parks and boulevards, even our finest estates tend to preserve some natural habitats and native mammals to look at, even in the largest cities. This coexistence of humans and wild mammals does not include a great many kinds of mammals. Neither does it extend much to the mammals of the north, the wetlands, vast prairies, or dense forests. Mammals that fit well into the urban surroundings, are those usually active and seldom seen at night that climb to safety into tree canopies or burrow in lawns, that have generalized diets, perhaps including mast from desirable lawn trees, and den in areas of ecological disturbance. Some perceived as cute and beautiful may become great nuisances. Insecticides and other contaminants. In this century natural history students must study the laboratory science of biochemistry, because many problems of pollution and chemical contamination of ecosystems will develop. Insecticides and other poisons such as DDT caused great problems to wildlife, since their use after World War II, but their effects on mortality of animal populations are not well known. Fortunately, the use of such poisons has been restricted greatly. After Rachel Carson, in her famous book Silent Spring, alerted the world about the eminent danger of insecticides, Wisconsin became the first state to ban DDT. Joseph J. Hickey and his student D. W. Anderson studied at the UW-Madison the reproduc-

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tive problems of raptors and DDT accumulation in their egg shells, which seemed to galvanize opposition to pesticides (1968-1969). Frederick Baumgartner, George C. Becker, Hickey, Hugh Iltis, Lorre Otto, Fred Ott, Leoni Vrtilk, William Reeder, and other supporters of the Citizens Natural Resources Association won this political battle. Other toxic substances that have been studied in our ecosystems include PCB’s, mercury, and numerous organophosphates. These have both direct and indirect dangers to wild mammals. For example, PCB’s poison fishes, which are eaten by mink, raccoons, and other mammals that feed extensively on aquatic animals. Bounty systems and other politics. Bounties have hurt some rather harmless species. Today this waste of taxpayer’s money is curtailed. A valuable role of predators in any ecosystem is now recognized. However, government often takes the side of businesses and urban development at a relentless expense of nature, and there are more and more, wider and wider roadways. Some people are satisfied if we save the big trees along the roads. But these old trees eventually will die. If most wild mammals could choose saving the great old elm or maple on the right-of-way or to save a patch of hazelnut, bluestem and cattail, they would not vote for the big tree. Why not save some of the native shrubby, grassy habitat along roads, and focus wildlife toward roadside culverts? Agencies involved with preservation of habitat include the Wisconsin Department of Natural Resources, state and private colleges and universities, some enlightened county governments, and several conservation societies such as The Nature Conservancy. Environmental education is stressed by several natural history museums and nature centers. In addition, the Wisconsin Academy of Science, Arts and Letters Transactions was an influential voice through Wisconsin history, publishing many studies on Wisconsin’s natural history.

ZOOGEOGRAPHY “So greatly has the climate of Europe changed that in Northern Italy, gigantic moraines left by old glaciers are now clothed by the vine and maize... a large part of the United States reveals a former cold period... As the cold came on, the temperate inhabitants would be supplanted by Arctic productions. The inhabitants of the more temperate regions would at the same time travel southward... the present circumpolar inhabitants, which we suppose everywhere travelled southward are remarkably uniform around the world... As the warmth returned, the arctic forms would retreat northward, closely followed up in their retreat by the productions of more temperate regions.” — Charles Darwin, On the origin of Species, 1859.

Nowhere does Darwin’s profound and pioneer thoughts on glaciation and animal distribution apply better than Wisconsin zoogeography. The distribution maps compiled herein may be compared with those made by Jackson (1961). The difference between the patterns is mainly due to current effects of land use. That is the chief factor now encouraging some southern mammals to disperse northward, and causing some kinds to vanish altogether. Zoogeography is a study of how the history and dynamics of climate and soils, both past and present, affect the vegetation patterns, which in turn influence animal distributions. Since the history of mammal geography in Wisconsin begins in the late Pleistocene following the Wisconsin glaciation, there are no records here of the early evolution of our marsupial, shrews, rodents and so forth, which took place long ago and far away. Three dramatic phenomena subsequently have affected our mammals. First, amelioration of the frigid Wisconsin glaciation, with subsequent warming of temperature, outwash of glacial meltwater, deposition of sands and loess, soil formation southward of sandy loams and many infertile soils, and the establishment of boreal forests chiefly spruce and fir. Some boreal mammals remained in the region and

some vanished from the warming lands. Later, invasions of southern prairie and deciduous woodland floras alternated (Thomson, 1940). Frye et al. (1965) discussed glaciation in Wisconsin and Illinois. With the new vegetation came the invasion of new mammals from the south, a few from the west, and a few that moved around Lake Superior into the boreal mixed and coniferous forests. Thus, a Holocene (i.e., Recent) fauna rich in diversity was established. Quite a number of interesting mammals became extinct (Lundelius et al., 1983; Graham, 1976; Semken, 1983; see Prehistoric Mammals below). The next upheaval of the mammalian fauna came when Caucasians settled Wisconsin. Native Americans had perhaps helped to eradicate some of the Pleistocene mammals, but insofar as is known, no habitats were destroyed by them. White settlers, however, left hardly an acre of good soil unplowed, seldom a square mile of heavy timber, or rarely a large game animal or valuable furbearer remaining anywhere. Only in remote regions did these mammals linger, until people with conservation ideals influenced society. That impact was preservation of forest reserves, reforestation, even re-establishing prairies, and scientifically managing game animals. Another dramatic change in mammal geography came in the past century from land use of modern society. Cities grow enormously, roadways multiply exponentially as does the population. Urban sprawl occurs when people try to escape from the cities, and many villages become towns, towns become cities, and everywhere people cut brush, plant lawns, and remove trees. DeVos (1964) discussed some changes in the known ranges of mammals in this region. Probably a general rule around the world, eradication of the largest meat mammals took place early. Eventually some mammals were eradicated for fur, or fear of their depredations. Reintroduction follows that rule in reverse, the reintroduction favors the largest mammals (Table Zoog-1, bats excluded). However, land use ENVIRONMENTS AND ECOLOGY OF MAMMALS

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and climatic change have recently and adversely affected mammals of all sizes. Most state collecting of Wisconsin mammal specimens prior to the 1970’s was done around the UW-Madison campus. The U.S. Biological Survey spent time and effort circling the state to pick up all possible species that peripherally entered it. Although noting some northward dispersion of mammals through the Central Sands area, my students and I (1970, 1974) collected numerous boreal mammals and some southern kinds endemic there. This gives the impression that boreal mammals unknown in the Central Sands, on Islands of Green Bay, and elsewhere were moving south. They were extensions of known range, not dispersions of actual range. For this reason, in my comparison with older zoogeography (prior to 1961, back to the turn of the 20th century) I include my records showing the occurrence of mammals (1965-1970), some of which now seem to be vanishing. Semken (1988), even without knowledge of my records in the Museum Reports and elsewhere, concluded that species richness in this region is greatest near Curtis’ tension zone. The mixture of northern and southern, i.e., boreal versus prairie and deciduous woodland species, is fantastic in west-central and central Wisconsin. Such a rich fauna should become famous and prideworthy for Wisconsin. Jones and Birney (1988) wrote a chapter on zoogeography for mammals of the Northcentral states. They mapped the range limits (boundaries of known ranges) for over 90 species in a so-called “spaghetti” map of the region. They found the aggregation of boundary lines notably intense in three areas, including one in southwest and south-central Wisconsin. They too concluded that the mammal pattern was largely congruent with vegetation patterns, and the vegetation developed on interesting soils and features of the PostWisconsin glaciation. I mapped my own “spaghetti” diagrams, one for Jackson’s (1961) maps with my early records included, especially based upon surveys

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of central Wisconsin (Table Zoog-2). This map showed two belts of grouped lines, one along the tension zone, the other a little southwestward. The more southern belt is basically a prairie boundary, for species (e.g., Bison) that did not range as far north as the Tension Zone. In the second map, based on more recent distributions discussed in this work, some populations seem, unfortunately, to have vanished recently (Cryptotis parva, P. maniculatus gracilis in the south, also Lepus townsendii, and Spilogale putorius). The major change primarily from land use in recent years is a loss of species in the center— of boreal (Sorex palustris, Eutamia minimus, western glacial-sands dwelling Pitymys ochrogaster minor), and southern affinity (Reithrodontdomys megalotis, Pitymys pinetorum, and perhaps others). Furthermore, numerous mammals recently (in historic times) have extended their actual ranges northward (Didelphis virginiana, Sylvilagus floridanus, Spermophilus tridecemlineatus, Sciurus niger, Glaucomys volans, Peromyscus leucopus, and others) and northeastward up to

Spaghetti diagram showing range limits of Wisconsin mammals approximately 1900. The packing of species near the tension zone is extraordinary for eastern North America. See text.

the tip of the Door Peninsula and into Upper Michigan (Didelphis virginiana, Spermophilus tridecemlineatus). Bats are not credited much as records, because of their mobility and extensive wandering, but the southern forms Perimyotis subflavus, Nycticeius humeralis, Myotis sodalis, and even Lasiurus borealis are not common in the northern counties. Tree removal in towns and along boulevards may have somewhat restricted the numbers and range of the red bat, even in the south, for Jackson (1961) reported it was the most abundant bat in [southern] Wisconsin. Jones and Birney (1988) used faunal “units” for assemblages relating regions to their mammals. A region is considered the origin for the mammal in our state if the mapped geographic range extends (peripherally) into this state from that direction. Widespread species have a more dubious origin. Ecological requirements, such as strict preference for grasslands, were used to help form these assemblages (i.e., “faunal units”). In their study of seven states ranging from the Canadian border to southern Illinois and Indiana, some of their

Spaghetti diagram for species from approximately 1960, showing range changes.

faunal areas extend well beyond Wisconsin’s borders. Excluding the out-of-state species used in their analysis, and many wide-ranging species such as bats and mobile carnivores, I also omit wide-ranging aquatic species such as muskrats (Ondatra zibethicus) and beavers (Castor canadensis) (in its former range).

Table Zoog-1. Zoog-1 Body size and extinction or eradication of known animals. Pleistocene to Recent. Game management saved some species. Only game animals and furbearers have been reintroduced. Mammals, weights, times. Wooly mammoth 5,000kg, Late Pleistocene Mastodon 5,000 kg, Late Pleistocene ?Ground sloth 3,000-5,000kg, Late Pleistocene Pleistocene bison 908 kg Pleistocene Plains bison 386 kg Late Pleistocene-historic American elk 363 kg Late Pleistocene,Historic Black bear 272 kg Late Pleistocene-Present Pleistocene caribou 227 kg Late Pleistocene Woodland caribou 182 kg ?Historic White-tailed deer 113 kg Late Pleist.-Present Cougar (Mountain lion) 91 kg Historic Giant beaver 91 kg Late Pleistocene Timber wolf 55 kg Historic, reintroduced American beaver Historic, vanished in south Canada lynx 20 kg Historic-Present rare Wolverine 18 kg Late Pleist. –?Historic Coyote 18 kg Historic-Present Bobcat 18 kg Historic-Present Raccoon 18 kg Historic-Present American badger 11 kg Late Pleist.-Present Fisher 6.8 kg Historic, Reintroduced Red Fox 6.8 kg Historic -Present River otter 11.3 kg Historic – Present Striped skunk 4.5 kg Historic-Present White-tailed jack rabbit 5.4 kg Historic-Present American marten 1.4 kg Historic, reintroduced Mink 1.5 kg Historic – Present Muskrat 1.5 kg Historic-Present Large weasels 100, 200 g Historic-Present Eastern chipmunk 100 g Historic-Present Meadow vole 50 g Historic-Present Vole P. pinetorum 40 g Historic-Present Vole P. ochrogaster 40 g Historic-Present Phenacomys 40 g Pleistocene Peromyscus 24 g Historic-Present Blarina shrew 18-24 g Historic-Present Water shrew 12-18 g Rare Historic-Present Harvest mouse 12-16 g Historic-Present Masked shrew 4-6 g Late Pleist.-Present Pygmy shrew 4-5 g Historic-Present rare Cryptotis shrew 5 g Historic ?eradicated ENVIRONMENTS AND ECOLOGY OF MAMMALS

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1. Widespread mammals — most of North America and having obscure direction of origin. 2. Eastern widespread — deciduous forests of the southeastern United States. 3. Eastern Austral — extreme southeastern United States. Perhaps Nycticeius humeralis. 4. Eastern New England — Northeast United States and southeastern Canada. 5. Plains/Grasslands — prairie forms from the south and west. 6. Boreo-montane — Forests of the Rockies or Canada. Widespread Mammals. In Wisconsin, the widespread mammals of obscure origin include bats Myotis lucifugus, Lasionycteris noctivagans, Eptesicus fuscus, Lasiurus borealis, and L. cinereus (which seems a southern species to me), wide ranging semiaquatics Ondatra zibethicus and Castor canadensis, deer mouse Peromyscus maniculatus (which acts as a species pair, i.e., both a boreal and a southern species in Wisconsin), porcupine Erethizon dorsatum, and carnivores Canis latrans (which seems southern in Wisconsin in relation to the wolf), C. lupus, Vulpes vulpes, Urocyon cinereoargenteus, Ursus americanus, Procyon lotor, Mustela frenata, N. vison, and Taxidea taxus (which is southern, perhaps Neo-tropical in origin except it was ages ago adapted to this frigid land even in the Pleistocene Epoch). Mephitis mephitis, Lontra canadensis (which is a northern Wisconsin species today), Felis concolor (which was eradicated), Lynx rufus (which is more southern possibly because of the boreal Canada lynx, but today has moved northward), Cervus elaphus (eradicated), and Odocoileus virginianus. There probably would be no objection to consider Peromyscus maniculatus bairdii and Lasiurus borealis as southern species, the former as a Plains/Grassland form, the latter perhaps the same (but it is highly mobile, always associated with trees, and migrates far to the southward). Eastern widespread faunal unit. Eastern species include the insectivores Crypto-

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tis parva and Scalopus aquaticus; bats Perimyotis subflavus; Nycticeius humeralis; cottontail Sylvilagus floridanus; and rodents Tamias striatus; Marmota monax; Sciurus carolinensis (but perhaps it invaded from New England?); Sciurus niger; Glaucomys volans; Peromyscus leucopus; and Pitymys pinetorum. Some of the above species now have occupied the entire state of Wisconsin and much of the Upper Peninsula. Most of them were, because of Lake Michigan intervening, from southern invasions, and are approaching or invading the boreal forests of the North Woods. Cryptotis and both Pitymys, however, seem eradicated or at least in peril. For the most part, land use favors these eastern species. This faunal unit thrives on roadways, park lands, and forest edge in modern Wisconsin. Eastern New England faunal unit. Apparently this assemblage had origin in the vicinity of the Gaspe Peninsula, and perhaps they even came from the north. Those species occurring in Wisconsin or approaching from northeast Minnesota have circled around the north shore of Lake Superior and invaded from the west. Therefore, to say they are eastern is like saying black is white; but their origin is east. These include Blarina brevicauda; Condylura cristata; Myotis keenii; Synaptomys cooperi; and Napaeozapus insignis. With the possible exception of the shrew Blarina, all these mammals are adapted to the northern conifers and mixed forests. They resemble in habitat the Boreo-montane element. Plains/Grassland faunal unit. These include: Lepus townsendii (probably eradicated recently); Spermophilus franklinii (southern grassland); Spermophilus tridecemlineatus (southern grassland); Geomys bursarius (western); Reithrodontomys megalotis (southern or western); Pitymys ochrogaster (one race is western, the other southern); Spilogale putorius (probably eradicated,

western); Bison bison (eradicated, western) (see section on Eradicated Mammals). Jones and Birney (1988) listed Reithrodontomys megalotis from the Southwestern Faunal Element, because the harvest mouse ranges into Mexico. It is a grasslands species that invaded Wisconsin arriving from southern or western states. Not discovered in Illinois until the 1950’s, the harvest mouse has moved eastward and northward. From southern and southwest Wisconsin it dispersed into central Wisconsin. It is restricted to prairies, meadows, old fields, hayfields, and marshes. The mouse seems to have a western-southwestern affinity with Geomys, Spilogale and the western race of Pitymys pinetorum, all from the Great Plains. Boreo-montane faunal unit. Even without including the somewhat boreal Eastern New England assemblage, this boreal and montane assemblage is the majority of Wisconsin mammals: Sorex arcticus; Sorex cinereus; Sorex palustris; Sorex (Microsorex) hoyi; Lepus americanus; Eutamias minimus; Tamiasciurus hudsonicus; Glaucomys sabrinus; Clethrionomys gapperi; Microtis pennsylvanicus; Zapus hudsonius; Martes americana; Martes pennanti; Mustela erminea; Mustela nivalis; Lynx canadensis; Alces alces. The two Martes are now reintroduced. The woodland caribou Rangifer tarandus and wolverine Gulo gulo have possibly historic records in Wisconsin; they also fit in the boreal faunal assemblange. Boreal Phenacomys intermedius might range into northwest Wisconsin from adjacent Minnesota. Although Sorex cinereus is obviously of boreal origin, and restricted from some southern habitats in Wisconsin, the evidence from mitochondrial DNA (Stewart and Baker, 1997) suggests Michigan shrews, and presumably Wisconsin shrews, show intermediacy between western populations (including Sorex haydeni ) and those from eastern Canada (and New England). The masked shrew probably invaded Canada after the Wisconsinan ice receded,

from refugia in southern and eastern (what is now) United States. Paleontological evidence proves the species has been here in early Wisconsin boreal habitats. That occurrence supports Stewart and Baker’s statement, based on the DNA “clock”, that the differentiation of these Sorex populations was probably before early Wisconsin time. Origin from the Deep South. The adaptable opossum (Didelphis virginiana) arrived centuries ago from a South American origin. It has invaded the northern counties, and finally reached Lake Superior, in upper Michigan. Zoogeography of Wisconsin Islands. The zoogeography of the islands at the mouth of Green Bay was discussed by Long (1978). New species of mammals (endemic Synaptomys cooperi jesseni, introduced Urocyon cinereoargenteus, and Peromyscus leucopus) are recognized from Washington Island. Unlike the Beaver Islands, more central in Lake Michigan, this group called the Grand Traverse Isles had a few endemic kinds in the early Holocene (i.e., Recent). They arrived by Fox River rafting, swimming, and crossing of the Lake ice in winter. Bats fly freely from isle to isle. Most hibernators are absent. Some kinds were introduced by humans (Long, 1978). Long (1978) reported that: 1. Only a few species were present on most islands, except the large Washington Island. 2. Often a species was exceptionally abundant. Never were two species abundant at the same time, except very different kinds such as red-backed voles and little brown bats on Poverty Island or deer and raccoons on Chambers Island. 3. The abundant species often had a widened ecological niche. For example, red-backed voles on Big Summer Island, Michigan, tunneled extensively. 4. Some species occurrences were unexpected, probably from chance rafting. Condylura on Big Summer Island is a good example. 5. Introductions by man was often a factor (e.g, Mephitis mephitis). 6. Animals that crossed lake-ice occur on most ENVIRONMENTS AND ECOLOGY OF MAMMALS

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if not all islands. 7. Large islands with diverse habitats have the most species present. 8. Islands in Green Bay resemble the Beaver Islands, eastward in Lake Michigan, only in the boreal mammals present. 9. Boreal mammals probably colonized these islands by crossing ice and by rafting, not by land bridges connecting isles together. However, Rock and Washington islands were once connected, and show faunal resemblance. On Washington Island are 15 species (including new P. leucopus, Urocyon cinereoargenteus, and Synaptomys cooperi), on Rock 8 species (new S. cooperi), and nearby in Michigan waters St. Martens Island (5), Poverty Island (4), Big Summer Island (8), and Little Summer Island (3). Chambers Island, in Green Bay, had six. The Garden Peninsula of Michigan had 23 species, and the north end of the Door Peninsula had 29, and they had a strong faunal resemblance. Resemblances were determined by a formula (Long, 1963) allowing comparison of large and small assemblages fairly, without so much influence from the large-value denominator due to the larger faunal assemblage. The first percentage is that of the Peninsula assemblage, the second is of the Wisconsin assemblage as listed by Jones and Birney (bats excluded). The percent resemblances are in Table Zoog-3. High values were found for Rock, Washington, and St. Martin’s islands. Big Summer and St. Martin’s islands had strong faunal resemblance. Across Green Bay, the boreal Garden and Delta peninsulas compare closely with the boreal north end of the Door Peninsula (containing Erethizon, Clethrionomys, Glaucomys sabrinus, and others). Three island species are unknown on the north end of the Door Peninsula, surprisingly, because it is so close to nearby Detroit, Washington, and Chambers islands. These are Condylura cristata, Synaptomys cooperi

jesseni, and Peromyscus maniculatus maniculatus (= gracilis). The forest deer mouse, driven off the Door Peninsula by P. leucopus (Long, 1996), persists on most of the isles (Long, 1974a; 1978 c; 1978a; 1990; 1996; Long and Long, 1993). Condylura cristata probably arrived at nearby Big Summer Island from Upper Michigan. Numerous mammals swim or cross the ice to these isles from the north shores of Green Bay, mostly Upper Michigan (Ursus, Lynx rufus, Urocyon, Vulpes, Canis latrans, Lepus americanus, and others). The bog lemming, Synapatomys cooperi, probably was endemic for thousands of years because it shows some speciation. The greatest faunal resemblance to the Peninsula fauna, using the simple ratio of number in common to total compared, is that of Washington Island (50 percent) and the least is that of tiny Poverty Isle (only 4 percent). Again we find that Rock shows a high affinity to Washington Island. All its kinds occur also on Washington Island. Comparing the fauna of the island group to that of the Faunal Units of Jones and Birney’s definition, all bats excluded, the results are given below. Boreo-montane 18%/ 36%; New England 7*/75*; Eastern 6**/22***; Plains/ grasslands 0/0;Wide-ranging 25/30. These percentage values are influenced by low numbers of Southeast, Grasslands and Neo-tropical units. The denominator is small, so the percentage is high. The north end of Door, decidedly less prairie-like than at the base of the Peninsula, has these affinities with Wisconsin units (bats excluded): Eastern 21% ; Eastern New England 25 % (only a single kind, Blarina); Plains/grasslands 4 %; Boreo-montane 25% . Much like mammals, not mobile and inactive in winter, the “herps” (reptiles and am-

* The bat Myotis keenii would swell this resemblance if bats were included. ** 7 percent if the recent white-footed mouse was counted. *** Includes the gray squirrel, which seems to me a New England kind.

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phibians) of this region faced similar difficulties in colonizing islands. Long and Long (1976) and Long (1994) studied the zoogeography of herps of the islands in Lake Michigan, finding little affinity with western Wisconsin herps, quite a strong resemblance to those from the south, and some to those from the east. The fauna of the land of Door, both peninsula and isles, is a mixture of boreo-montane and deciduous woodland mammals or herps. Surveys in the Apostle Islands have proved less interesting. Little speciation is apparent and the small mammals and most bats are boreal. The red bat may not be long established. Only a few species of mammals are present. Zoogeography Of The Central Sands. Comparing the rich tension zone fauna of the Central Sands area, within the square area of Marathon, Wood and Portage counties, with the list in table Zoog-2, the faunal resemblance (bats excluded and extirpations not considered) is 91 percent (N 33). That is extremely high, a rich mixture of all kinds of mammals, as mentioned above. Central Wisconsin mammals of aforementioned Faunal Units [percent of central species/percent of faunal unit] are: Neotropical 1, 3%/50%; Plains/grasslands 4, 12/66; Eastern widespread 9, 27/90; Eastern New England 4, 12/100; Boreo-montane 17 50/100. This species-rich savanna area with boreal forest northward and hickory-maple, oakjack pine, wet and dry grasslands, and other habitats, has a fauna involved with all the aforementioned units. It is primarily eastern (deciduous woodlands) and boreo-montane. Some grasslands forms are present, and the opossum from the southern United States is now well established. Future Changes And Grounds For Optimism. The future biogeography of Wisconsin will probably show a proportion of the mammal fauna invading farther north, some reintroduced carnivores (and also the moose) dispersing farther south, and other mammals driven northwards by the advancing southern mammals. Some boreo-montane mam-

mals receding northwards will vanish in numerous counties within their former range. The forests in the north are now favorable to these species. The interesting and diminutive glacialsands race of the prairie vole, Pitymys ochrogaster minor, has been greatly decimated. Its status is confused, probably extant, but the whereabouts at present are unknown. A few other species have vanished or become rare. Most of the Eastern Widespread species are doing well and will likely continue to do so. The introduced mammals may continue to flourish, except Lepus townsendii. Mar-

Table Zoog-2. Some species used for spaghetti diagrams and faunal estimates. Wide-ranging species excluded. Origin (N, S, W) and species.

Opossum N Star-nosed mole N or NE Prairie mole S, SE Arctic shrew N Water shrew N local, rare Pygmy shrew N Uncommon Least shrew S, SE extirpated White-tailed jack rabbit W eradicated Snowshoe hare N 13-lined ground squirrel S Franklin’s ground squirrel S, scarce Least chipmunk N Red squirrel N Fox squirrel S Southrn flying squirrel S, SE Northern flying squirrel N Plains pocket gopher W Harvest mouse W, SW uncommon Prairie deer mouse S Forest deer mouse N, NE White-f ooted mouse S, SE Pine vole S, W also. Rare Prairie vole S, W also. One race rare. Red-backed vole N Woodland Jumping mouse NE Porcupine ?N Ermine N Least weasel N Scarce Spotted skunk W River otter N Canada lynx rare NW Bobcat S Moose N, NW ENVIRONMENTS AND ECOLOGY OF MAMMALS

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tes foina may expand its range and numbers. There need be no protection provided for Mus, Rattus, or feral cats, all of which should be humanely disposed. Along the southern border of Wisconsin, we may expect rare bats to retreat southward, even if the temperature continues warming. They are incompatible with intense urbanization and sprawl. Some western species may extend their ranges eastward across Wisconsin, crossing and working northeast along the rivers, if they can cope with land use. One or two of the “New England” kinds may enter Wisconsin in the northwest, from Minnesota. In the forested north most kinds should sur-

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vive. In Door County, southern invaders will move up the peninsula, and some may cross to nearby isles. Some species there may not survive (Erethizon dorsatum, Glaucomys sabrinus, several carnivores) because of land use and growing population there. The rich species diversity in central Wisconsin may lose some species. Who cares what happens in the center? With future efforts of our modern Wisconsin natural resources agency, I expect that few species will disappear from Wisconsin. Probably some eradicated mammals may be transplanted and reintroduced. There are so many lovers of nature in this wonderful state that one can guarantee a happy future.

Wooly Mammoth. Woodcut G. Cuvier. Regne animale. THE WILD MAMMALS OF WISCONSIN

PREHISTORIC MAMMALS All of the prehistoric mammal kinds of what is now called Wisconsin invaded from outside this region. Their Wisconsin history does not extend far back in geological time, their fossils are unknown in our long-buried sedimentary rocks. In many places the heavy glacial ice of ages past scoured away these rocks, and the resulting outwash sands buried other rocky strata. The early history of Wisconsin mammals must be traced back through time in far away places. The Pleistocene glaciations, mentioned earlier in the Environment section, were, in chronological order, the Nebraskan, Kansan, Illinoian, and finally, and least extensive of the four, the Wisconsinan. Many Kansan and Nebraskan deposits are confused and often identified as “Pre-Illinoian.” The last stage, the Wisconsinan glaciation, probably ameliorated (melted, retreated) in southern Wisconsin some 15,000 years ago, and the complete withdrawal of ice from northern Wisconsin and the Great Lakes occurred about 10,000 years ago. This marked the end of the Pleistocene, and commenced what is called Recent time (also called the Holocene Epoch). There were several advances of Wisconsin ice. Pollen analysis and carbon dating have helped us understand Holocene events by the occurrence of certain trees and grasses. Near Green Bay (Two Rivers, Peter’s Quarry, Duck Creek) and westward near Iola (the Iola Bog) bogs provide a record of former plants and pollen. It shows that black spruce, tamarack, and some grasses (Cyperaceae) were replaced 11,640-11,850 years BP [BP= before the present], after the Cary ice advance and during the warmer Two Rivers Interval by a shift to more composites and dry prairie grasses. After the last advance of ice, called the Valders Re-advance, the great invasion of the region by white pine and oak (Schweger, 1969) commenced. Boreal forests and probably boreal mammals gave way to, or were mixed with, the arrivals of southern mammals associated

with the pine and oak forests, especially throughout the southern half of present Wisconsin. Open country became prairie lands and wet marshes. Forests on Valders moraines joined those of Cary moraines. The Door Peninsula and the surrounding waters were uncovered of ice. Evidently early humans arrived about this time. Since then the climate has fluctuated, becoming even warmer than we enjoy at present. Giant beavers (Castoroides), which did not build dams or lodges, lived in glacial meltwater lakes (Dallman, 1969). Two huge members of the elephant family, the plant-foraging mastodon (Mammut) and the woolly mammoth (Elephas), ranged through the woodlands and dense spruce forests near the ice fronts. The mammoth probably ate grasses, leaves, and twigs. Giant flat-headed peccaries (Platygonus ), huge bison (Bison occidentalis), a large boreal caribou (Rangifer tarandus), and even musk oxen (both Symbos and Ovibos) inhabited the boreal woodlands near the retreating ice fronts. The lemming Dicrostonyx, a small rodent, lived in this region, and was preserved at many Pleistocene sites outside Wisconsin. Now it is confined to the Arctic. One huge mammal not yet found or reported in Wisconsin is the giant ground sloth (Megalonyx). The elk-like long-legged moose (Cervalces scottii ) was recently found in Marathon County, buried where the Wisconsin ice front had melted away (Long and Yahnke, in press). Several species of whales and the walrus swam in Lake Michigan (Handley, 1953) and probably visited the western shore. [I examined a Pleistocene whale vertebra from a Wisconsin gravel pit, but the antiques dealer who owned it refused to divulge the locality of this “valuable dinosaur find.”] Both warming climate and activities of early human cultures seemed adverse to the large (and probably shaggy) ice age mammals, for many became extinct. They left only teeth and bones buried in bogs, swamps, and flood plain soils to document their presence. Many PREHISTORIC MAMMALS

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medium-sized and small species persisted, some retreating northward following the retreating cool conditions. Others from the southern hardwood forests (deciduous forest species) and steppe species (Hoffmann and Jones, 1970) from the vast interior grasslands (or Great Plains) invaded the “uncovered” and open habitats. Some deciduous trees and mammals may have overextended northward in the warmest seasons, as oaks, hickories and other southern plants established themselves into northern Wisconsin, some mammal populations persist today as relicts. Most boreal species in Wisconsin today inhabit northern spruce, pine, maple, and eastern beech-maple forests. There is a rich “amalgam” of these and warmth-adapted species especially in southwest and central Wisconsin. Along Wisconsinan ice fronts the Holocene and late Pleistocene fossil sites reveal diversity (Semken 1988; Thompson, 1940; Foley, 1984; Thieling, 1973; Rasmussen, 1971). Whether microhabitats were diverse, free intermingling of the post-Pleistocene mammals, or climatic fluctuation caused this species stacking is uncertain. Some small fossil assemblages were concentrated together (by means unknown, probably by snakes, in some cases by owls, possibly by ants) in rock fissures, sinks, and caves. Fragmentary parts of the skull and teeth are most abundant at such sites. Cave deposits on the Door Peninsula carbon-dated at one level at 600 BP, according to Robert Howe (personal comm.), contained numerous remains of some modern-day mammals, probably even Pitymys pinetorum. Mastodons excavated by Dallman (1968) near Deerfield, Wisconsin, in Dane County, were aged as 9,480 BP, and 10,095 (or a little older). Dallman aged a woolly mammoth, roughly contemporary in time and place with the mastodons, as 9,065 BP. This elephant was found at Lake Mills, in Jefferson County. Other large mammals (Bison occidentalis, Castoroides ohioensis, and Rangifer tarandus) are likely as old.

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The Moscow Fissure in the “Driftless Area” yielded fossils carbon-dated at roughly 17,000 BP, at the peak of Wisconsinan glaciation (Rassmussen, . The hilly area was practically encircled by massive ice fronts, both westward and eastward. Many boreal and Arctic species and genera were present, including Dicrostonyx, Synaptomys, and Phenacomys, including some species known today far to the westward (Table Pre-1). There are no records of Deciduous-Woodland species. The number of species of shrews and voles is high, suggesting boreal climate (Graham 1976). The Moscow Fissure fauna showed greatest affinity with mammal communities of present-day, southeast Manitoba and southwest Ontario (and perhaps northern Minnesota). From one site in western Wisconsin, now destroyed to make a park, Palmer (1954) discussed 300 Bison occidentalis that were associated with Native American remains. He (1974) also found the giant peccary Platygonus. The fauna of Lost River Sink (Table Pre-2) seems similar to the same fauna found there today. At Lost River Sink, at level 3, the age is 2,720 BP, and at level 4, it is 3,970 BP. The

Table Prehist.-1 Prehist.-1. Recent and former species’ facies from the Moscow Fissure, Wisconsin. This area not covered with glacial ice. However, the fauna changed drastically. All the older species either retreated out of Wisconsin, or live mostly in northern counties. Sorex hoyi ranges south. 17,000 BP

Recent species

Sorex arcticus Sorex palustris Sorex hoyi Thomomys talpoides* Clethrionomys gapperi Synaptomys borealis* Phenacomys intermedius Microtus xanthognathus* Dicrostonyx torquatus* Zapus princeps*

Didelphis virginiana Cryptotis parva Scalopus aquaticus Tamias striatus Glaucomys volans Geomys bursarius Reithrodontomys megalotis Peromyscus leucopus Pitymys pinetorum Zapus hudsonius

*No longer in Wisconsin

Table Prehist-2 Prehist-2. The Lost River (L) , Moscow Fissure (M), and other sites are represented by numerous species. The older species from M are shown here. L seems recent.

small mammal fauna, then, has been fairly stable for nearly 4,000 years in southern Wisconsin. The modern species are, of course, described in their species accounts beyond. Elk antlers from Portage County were buried after being shed along streams, and may not be of great age. A huge subfossil specimen from NE Columbia County is in the UW Wildlife Ecology collection. I saw a bison tooth from a field near the Wolf River east of Stevens Point, but there is no certain evidence of a natural burial. Archeological digs often yield some fossil remains, and many fossils are discovered by accident (in excavations). Attention to cave deposits and fissures provides many Recent fossils and subfossils. The small mammals are often obtained by washing and screening techniques. The huge bones of the large species are often found buried in lake beds, bogs, and

Sorex arcticus M, S. palustris M, S. hoyi M, S. cinereus M, L, Myotis sp. L, Perimyotis L, Lepus americanus ?M, Thomomys talpoides M, Sciurus sp., L, Tamias striatus L, Spermophilus tridecemlineatus L, Tamiasciurus hudsonicus M, Peromyscus maniculatus L, Synaptomys cooperi L, Clethrionomys gapperi M, Pitymy pinetorum L, P. ochrogaster (large race) L, Phenacomys intermedius M, P. ungava (M?), Castor canadensis, Castoroides ohioensis, Mammut americanun, Elephas primigenius, Tayassu, Platygonus compresses, Cervus elaphus, Rangifer tarandus, Bison occidentalis (= latifrons), B. bison, Ovibos, Symbos cavifrons, Ursus americanus L, Procyon lotor L, Mephitis mephitis L, Vulpes vulpes L, Canis cf. lupus, Gulo gulo, Jackson 1961.

Pleistocene Bison latifrons. After Hamilton, 1939. PREHISTORIC MAMMALS

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Bison bison. William T. Hornaday. His writings probably saved this species. It is now domesticated in Wisconsin.

flood plain sediments where the smaller forms are not preserved. When a fossil site is dis-

covered it should be immediately reported to professional geologists, and if possible left undisturbed. Fossils collected without accompanying data are worthless. Usually a plan can be worked out to accommodate all interested parties at a fossil site.

Pleistocene and post-Pleistocene records of large Ice Age mammals showing Mammut mastodon; Elephas mammoth; Bison; and Rangifer caribou. The Wisconsin drift and lobes are also shown. The Bevent site contained two caribou and the only Cervalces scotti elk-moose (above) known in Wisconsin. The fossil elephant sites lie south of the Laurentide Wisconsin ice sheet, or near it as it receded. The large caribou are from the glaciated southeast or central part of what is Wisconsin, found in wetlands near moraines. Bison, as in pioneer times, ranged along the west border of Wisconsin as this region was to become prairie and woodland. West and Dallman, 1980, Long, 1986, West, 1978. Map and photo by C. Yahnke.

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REINTRODUCED AND EXTIRPATED MAMMALS OF WISCONSIN WITH HYPOTHETICAL LIST OF SPECIES POSSIBLY IN WISCONSIN How does one know whether secretive species are unknown or eradicated? Some species are very difficult to detect. This listing supplements the list of earlier Pleistocene and early Post-Pleistocene mammals eradicated by warming climate, human activities, and unknown causes. Eradication of mammals from Pleistocene and Holocene Wisconsin generally was related directly to the mammal’s body mass (probably important both for cold weather subsistence and for the Native Americans for food—Table Zoog-1), climatic warming (which affected Ice-Age mammals regardless of their mass), fur use, intolerance to predators by farmers and hunters, and land use (i.e., habitat alteration, which is affecting the holdovers from earlier eradications). Natural and scientifically managed reintroduction generally follow the same rules (without any reintroductions of Arctic species, of course), generally in the same sequence, but eradication of the small mammals may be far from ending. Their geographic ranges are constantly changing, favoring in some cases the species scientifically managed, with some others indirectly benefiting from the management, many southern invading species, such as Glaucomys volans, and some that adapt well to modern land use (e.g., Didelphis, Eptesicus, Sylvilagus, Spermophilus, Sciurus niger).

Felis concolor. Woodcut. Joseph B. Holder. The Mus. Nat. Hist., by Sir John Richardson et al. 1877.

The reintroduction of small mammals has not yet begun (Long, 2001). Some mammals introduced or reintroduced in Wisconsin are surviving, and even thriving. They are mentioned here and treated in detail in the species accounts below. Some eradicated native kinds reintroduced are sometimes of a different geographic race (e.g, Cervus elaphus nelsoni). If eradicated before historic time, the species are discussed in Prehistoric Mammals. If eradicated in historic times, up to approximately 1900, they are included immediately below. Cryptotis parva. Least shrew. This shrew may have vanished about 1940. See account of the least shrew. Lepus townsendii. White-tailed jack rabbit. Possibly native in southwest and northwest Wisconsin, introduced in many places in the state, and possibly eradicated about 1970. See account of this species. Rattus norvegicus. Norway rat. An introduced and established pest. See account of this species. Mus musculus. House mouse. An introduced and established pest. See account of this species. Martes americana. Pine (or American) Marten. See account of this reintroduced species. Martes pennanti. Fisher. See account of this reintroduced species. Gulo gulo. Wolverine. Possibly eradicated. Jackson (1961) reviewed the history of this problematic, large mustelid, under the name Gulo luscus luscus, the only specimens of which are sub-fossils from cave deposits. There are dubious reports in early newspapers. See Prehistoric Mammals. Felis concolor (= Puma concolor) probably the race coryi. Mountain lion or cougar. The native lion Felis concolor schorgeri was eradicated in the last century. Unauthorized releases of cougars, likely the Florida cougar, have occurred. Department of Natural Resources biologist Adrian Wydeven records all reports annually, so far dubious, invalid, and possibly valid. Jackson (1961) reviewed early

REINTRODUCED AND EXTIRPATED MAMMALS OF WISCONSIN

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records. One record I investigated that may have led to several of the reports in the Richland Center and Blue River areas probably was a release of one or both of a pair brought from Florida and fed on road-killed deer. The owners left the state separately, and the cougars did not leave with them. Observations were frequent in the region; these were among the first reports of cougars thought to have returned to Wisconsin. Cervus elaphus nelsoni. A reintroduced species, in spring, 1995, into the Clam Lake Area, were 25 individuals, some that died, but some are producing calves under strict protection. This race might replace in remote areas our extirpated Cervus elaphus canadensis. The Yellowstone-Jackson Hole herd that provided so many reintroductions of elk in America (see Long, 1965) provided at least one in Wisconsin (at Trout Lake in 1913 and 1917). These elk were reportedly in poor condition, but the photos in Jackson (1961) are of healthy Montana stock. These introduced elk did not range out of Vilas and Oneida counties, and did not survive later than 1950. The Jerome Hunting and Fishing Club at Mercer, in Iron County, near Trade Lake, used elk from Montana, and failed to establish elk. In 1995, the governor T. Thompson and others persuaded the Department of Natural Resources to make another attempt. Cervus elaphus canadensis. American Elk, Wapiti. Jackson (1961) reviewed the historical records, and there are numerous antlers from prehistoric Wisconsin (see that Section). He believed this race of elk was eradicated by 1875. It formerly was wide-spread. Alces alces. Moose. American Moose. The moose was probably eradicated at the turn of the century, with the last record near the Minnesota border in 1921 (see Jackson, 1961). Some small groups may have survived in remote northern marshes. Today there are breeding records nearly every year for moose that apparently reintroduced themselves in northern Wisconsin. See account of that species.

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Rangifer tarandus sylvestris (Richardson, 1829). Caribou. There are no records of this species, which may have been present and eradicated about 1910 (Jackson, 1961). The species seems to have persisted in northern Minnesota. A possibly valid record for Wisconsin is given by Schoolcraft (1831). There are some records of a larger bodied strain of caribou, from Prehistoric Wisconsin (see that Section). Bison bison bison. North American Bison or American Buffalo. Eradicated. Bison ranged into southwest and southern Wisconsin on the prairies and savannas. Their status was reviewed by Jackson (1961), who reported that the last of them was killed by “Sioux Indians” in 1832. In the display at Kettle Moraine State Forest there is a buffalo robe donated by James Brom (“from Lower Hebron Road”, ostensibly shot by John Mall’s grandfather in the early 1840’s. It was shot on Mall’s farm near Rome Pond [Jefferson Co.]. If this record is valid (which seems likely) then the buffalo survived in some small numbers nearly ten years longer than Jackson thought, and this robe, preserved (“rolled up”) in Mall’s barn, is the only known bison specimen from Wisconsin from the pioneer stock. Bison have been reintroduced into several protected areas, such as the Sand Hills Demonstration Area near Babcock, and to numerous game farms. Today there is a growing number of people undertaking to raise bison as domestic beef animals. This is a great example of what can happen to an animal once nearly extinct, but through extensive efforts of William T. Hornaday and his supporters was saved from extinction (see Long, 1965). Now it is useful to humankind again. Hybrids called “cattalo” may be obtained by crossing Bison and domestic cattle. Some mammalogists refer Bison to the genus Bos. I note the hybridization is not successful in some crosses and the hybrid is obviously less viable than the bison. Therefore, I am not persuaded to consider the bison in Europe and North America, with their many fossil species, as conspecific with domestic cattle.

Felis catus. The house cat is not treated in this book as a wild species. It is more domestic than, say the house mouse (Mus musculus), although feral cats are important and in many situations (especially in the southern counties) as self-sufficient as the mice. If humans would cease partially feeding and renewing the numbers of feral cats (by releases and keeping too many), probably the feral cats would soon disappear. House mice require no care from humans except in laboratories. John Coleman (1995) and Coleman and Temple (1993) found that farm-dwelling house cats (Felis catus), more or less feral and especially in southeast Wisconsin, make a huge impact in ecosystems by predation on songbirds, and even more on small wild mammals. The feral and domestic cats together may be the major predator in the state, especially in the agricultural and urban habitats. Coleman estimated that over 14,000,000 Wisconsin songbirds were killed annually by free-ranging cats, and double that number must be added to the predation by city and rural pets. The incredible total should make every cat loving naturalist pause for thought, 14 million song birds in only one state. Many more small mammals than that are killed, although these may be less beneficial. The average number of farm cats was between 8-9 cats, and at non-farm rural homes about 4 to 5 cats. The presence of up to 35 cats at a single farmstead was not uncommon. Farmers seemed overwhelmed by their own cats, hoping someone would help with their disposal. Farmers limit the numbers of cats by how much they feed them, but usually provide only sufficient food for approximately five. Ten cats survive on the rations for five. Each hungry cat may kill as many as 100-600 birds locally per year, as well as many small mammals. Although unwanted cats on farms may be shot, few (only 13 percent) are neutered. Compared to a density of about 34 raccoons, five skunks, and 18 opossums per square mile, the density of cats, at 104 per square mile, seems incredible. Cars and diseases kill many

cats, which show rapid turnover, especially of males. Some diseases are transmitted to humankind by cats, and Toxoplasma is a real threat to the offspring of pregnant humans. Exotics. Some exotics and interesting records that I have learned about in Wisconsin include a prairie dog living at least 8 years

American elk (= Wapiti). Tho(?) Lundeen,1835, Cuvier’s Animal Kingdom, 1863.

Sika deer Japanese exotic. Flower and Lydekker, 1891. By Lord Powerscourt.


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in southwest Wisconsin (brought to my attention by Scott R. Craven), and one nutria near Stevens Point (1963) (see Long, 1970). Sika deer (Cervus nippon) escaped or were released from a game farm in southeast Wisconsin, and, reportedly, Fallow deer were released as well, where hunters have reported seeing adult deer with spots. Sika deer are smaller than either Fallow or white-tailed deer, and have slender antlers in the males. In addition to white spotting, there is a dark mane in winter and a conspicuous white rump patch. The fallow Deer (Dama dama) is probably eradicated. It can be identified by larger body size and flattened palmate antlers (in males only) having numerous points. Wydeven and Wiedenhoef (2002) record the odyssey of a wolverine that escaped from a game farm in Marquette County, apparently was observed several times in the wild, and likely was the wolverine killed on the road in Rock County in December 2001.

HYPOTHETICAL LIST OF MAMMALS POSSIBLY OCCURRING IN OR INVADING WISCONSIN Some mammals that may in the future be found in Wisconsin may have been here all the time, undetected, or they may invade the state if habitats become favorable for range dispersion. Most of the mammals listed here are nearby or mobile enough to invade Wisconsin. Sorex fumeus fumeus Miller, 1895. A dubious record is the U. S. National Museum specimen from southeastern Wisconsin, sent from Racine by Dr. P. R. Hoy, in 1853. There are no other Wisconsin records, nor do the habitats at Racine seem appropriate. The known geographic range of the species was hundreds of miles away (Kentucky and northern Ohio). Probably the Wisconsin locality was that of Hoy, not of his specimen. A mistaken Racine locality was likely also for Microtus xanthognathus (see below) and Sorex (Mi-

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crosorex) hoyi (holotype, see Long, 1972a). However, the species S. fumeus reportedly (but never verified) recently invaded northeast Minnesota, near the northwest Wisconsin border, circling around the north shore of Lake Superior. I have not seen the specimens (see Jannett and Oehlenschlager, 1994). The species is clearly recognizable by flattened skull, dark venter, and size intermediate between the masked and arctic shrews, which have high arched crania and mistakenly have been said to resemble fumeus closely. The tail exceeds 38 mm in length. Perognathus flavescens Plains Pocket Mouse. This heteromyid, having external cheek pouches and elongate hind limbs, has four upper cheek teeth on each side, the dorsum is cinnamon buff, the venter creamy white, and the upper incisors are grooved. It inhabits dry sandy prairies across the Mississippi River in Minnesota, but is rare there. Microtus chrotorrhinus Rock Vole. Known from one record in northeast Minnesota. The vole is boreal and might have lingered in Wisconsin in some boreal, rocky habitat. It has an orange patch on the nose, and tends to yellowish brown dorsally, whereas the venter is white. Microtus xanthognathus. Yellow-cheeked Vole. Recorded under the name Arvicola xanthognathus, yellow-cheeked vole, by Lapham (1853: 340). The locality Racine would indicate the record was based on Hoy’s notes. The species is unknown from Wisconsin. Phenacomys intermedius. The Heather Vole may occur in northwest Wisconsin on sandy grassland or dunes. It occurs in northeast Minnesota, and I have collected it in Ontario a short distance north of Lake Superior. The cheek teeth are dark blackish, and especially in the lower jaw show deep re-entrant angles that almost cut through the teeth. The nose and rump are tan, and the venter is white. Rattus rattus. Roof Rat or Climbing Rat. This long and scaly tailed rat, also called the black rat, regardless of its color, will likely be

found in Milwaukee, Green Bay, or at some port city on Lake Michigan, establishing itself briefly as an introduced rat. It was once taken in Chicago. The tail is longer than half the total length, but see account of one long-tailed rat under Rattus norvegicus. Antilocapra americana. Pronghorn. By the name Antilope americana, included with the Wisconsin mammals by Lapham (1852: 44; 1853: 340), who cites only “N. W. Territory, (Mr. Say)”. Hoy (1882: 255) concurred, believing the pronghorn ranged as far east as Lake Michigan”. There is no evidence the pronghorn ever occurred in Wisconsin, although ranging into Iowa.

VISITANT BATS Transported by winds, and often flying in long dispersals of young-of-the-year, various bats often are found far from their normal breeding ranges. Those taken near Wisconsin include the Mexican free-tailed bat, Tadarida brasiliensis, which has the tail extending well beyond the uropatagium; the small-footed Myotis, Myotis leibii, which is yellowish, has a dark mask on its face, and the calcar is keeled; the gray bat Myotis grisescens, which has gray color all the way from the tips of the hair to the bases, and the wing membrane attaches to the ankle above the foot.


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CHECK-LIST OF WISCONSIN’S WILD MAMMALS

Sylvilagus floridanus Eastern Cottontail ..................................... 150

With the names of orders and families

Order Rodentia Sciuridae Marmota monax Woodchuck or Groundhog ................................... 158 Spermophilus tridecemlineatus Thirteen-lined Ground Squirrel ...... 164 Spermophilus franklinii Franklin’s Ground Squirrel ........................... 171 Eutamias minimus Least Chipmunk ..... 175 Tamias striatus Eastern Chipmunk ...... 180 Tamiasciurus hudsonicus Red Squirrel ........................................ 187 Sciurus carolinensis Gray Squirrel ...... 193 Sciurus niger Fox Squirrel ................... 203 Glaucomys sabrinus Northern Flying Squirrel .............................. 210 Glaucomys volans Southern Flying Squirrel .............................. 214

Order Marsupialia Didelphidae Didelphis virginiana Virginia Opossum .... 69 Order Insectivora Talpidae Condylura cristata Star-nosed Mole ...... 76 Scalopus aquaticus Eastern or Prairie Mole ................................... 81 Soricidae Sorex cinereus Masked or Cinereous Shrew ............................................ 86 Sorex arcticus Arctic Shrew .................. 89 Sorex palustris Water Shrew ................ 93 Sorex (Microsorex) hoyi Pygmy Shrew ............................................ 97 Blarina brevicauda Northern Short-tailed Shrew ........................ 101 Cryptotis parva (eradicated?) Least Shrew .......................................... 106 Order Chiroptera Vespertilionidae Myotis keenii (= Myotis septentrionalis) Keen’s Myotis or Keen’s Bat ......... 114 Myotis lucifugus Little Brown Bat ....... 117 Myotis sodalis Indiana or Social Bat .... 121 Lasionycteris noctivagans Silver-haired Bat ........................... 124 Perimyotis subflavus Georgian Pipistrelle ..................................... 127 Nycticeius humeralis Evening Bat ....... 130 Eptesicus fuscus Big Brown Bat .......... 131 Lasiurus borealis Eastern Red Bat ....... 135 Lasiurus cinereus Hoary Bat ............... 138 Order Lagomorpha Leporidae Lepus townsendii (eradicated?) White-tailed Jack Rabbit ............... 144 Lepus americanus Snowshoe Hare ..... 146

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Castoridae Castor canadensis American Beaver ... 220 Geomyidae Geomys bursarius Plains Pocket Gopher ........................................ 229 Muridae Reithrodontomys megalotis Western Harvest Mouse ............................. 236 Peromyscus leucopus White-footed Mouse ..................... 241 Peromyscus maniculatus (maniculatus and bairdii) Forest and Prairie Deer Mice ................ 252, 257 Clethrionomys gapperi Red-backed Vole ............................................ 262 Pitymys ochrogaster (= Microtus ochrogaster) Prairie Vole .............. 267 Pitymys pinetorum (= Microtus pinetorum) Pine Vole ................... 274 Microtus pennsylvanicus Meadow Vole ............................... 280 Synaptomys cooperi Southern Bog Lemming ..................................... 286

Ondatra zibethicus Muskrat ................ 292 Rattus norvegicus (introduced) Norway Rat .................................. 299 Mus musculus (introduced) House Mouse ......................................... 301 Zapodidae Zapus hudsonius Meadow Jumping Mouse ......................................... 305 Napaeozapus insignis Woodland Jumping Mouse ............................ 311 Erethizontidae Erethizon dorsatum North American Porcupine .................................... 316 Order Carnivora Canidae Canis latrans Coyote .......................... 323 Canis lupus (reintroduced, from Minnesota?) Timber Wolf or Gray Wolf .... 330 Vulpes vulpes Red Fox ....................... 339 Urocyon cinereoargenteus Gray Fox .... 345 Ursidae Ursus americanus Black Bear ............. 351 Procyonidae Procyon lotor Raccoon ....................... 359 Mustelidae Martes pennanti (reintroduced) Fisher .......................................... 369 Martes americana (reintroduced) Pine Marten or American Marten ......... 375 Martes foina (introduced) Stone Marten ......................................... 378 Mustela nivalis Least Weasel .............. 382 Mustela erminea Ermine ..................... 387 Mustela frenata Long-tailed Weasel .... 392 Neovison vison Mink .......................... 398 Gulo gulo (Prehistoric or eradicated) Wolverine*

*

Mephitis mephitis Striped Skunk ........ 404 Spilogale putorius (eradicated?) Eastern Spotted Skunk ................. 410 Lontra canadensis (= Lutra canadensis) River Otter ................................... 414 Taxidea taxus North American Badger ......................................... 421 Felidae Felis concolor (= Panthera concolor or Puma cougar) (eradicated) Mountain Lion or Cougar Lynx canadensis (nearly eradicated) Canada Lynx ................................ 428 Lynx rufus Bobcat .............................. 433 Order Artiodactyla Cervidae Cervus elaphus (eradicated, now partially domesticated) Elk or Wapiti Odocoileus virginianus White-tailed Deer ............................................ 440 Alces alces (eradicated?, re-colonized from Minnesota) Moose ........................ 450 Rangifer tarandus (eradicated) Caribou Bovidae Bison bison (eradicated, now partially domesticated) Bison or American Buffalo

A “Trivia” question: What Wisconsin mammals are known by fewer than five reports or specimens today? Least Shrew, Indiana Bat, Evening Bat, White-tailed Jack Rabbit, Franklin’s Ground Squirrel, Stone Marten, Spotted Skunk, Canada Lynx, and several kinds eradicated long ago.

Gulo gulo. Jackson (1961) recognized the wolverine Gulo luscus (= Gulo gulo) as a Recent mammal; it is no longer in the state and perhaps eradicated. Possibly this mammal was prehistoric. CHECK-LIST OF WISCONSIN’S WILD MAMMALS

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KEY TO ORDERS AND FAMILIES OF WISCONSIN MAMMALS 1

Incisor teeth 1-5/1-4 (= 5/4) on each side; marsupium present in females, epipubic bones present, hallux opposable to hind toes ............ Order Marsupialia: Didelphidae Opossum 1' Incisor teeth not 5/4, marsupium and epipubic bones lacking, hallux never opposable to toes ................................. 2 2 Flight membrane comprised of finger webbing, fingers elongated but claws lost from disuse excepting that of thumb .... .............................. Order Chiroptera: Vespertilionidae Bats 2' Flight membrane lacking except lateral membrane between wrist and pes present in Glaucomys, claws or hooves present on digits ........................................... 3 3 Upper incisors absent, digits provided with hooves .......... Order Artiodactyla: Cervidae Deer 3' Upper incisors present, digits having claws ............................................... 4 4. Diastema present behind gnawing incisors ................................................. 5 4' Diastema lacking in tooth row ........... 6 5 Incisors 1-2/ 1 (=2/1) but the second is a minute peg, hind limbs elongated for saltatorial locomotion, pinnae of ears elongated ............. Order Lagomorpha: Leporidae Hares and rabbits 5' Incisors 1/1, hind limbs and ears usually short .......................... Order Rodentia: Sciuridae, Geomyidae, Castoridae, Muridae, Zapodidae (this group has long hind legs but short ears), and Erethizontidae 5A External cheek pouches present, front feet larger than hind feet .................... ................. Pocket gopher Geomyidae 5A' External cheek pouches lacking, front feet smaller than hind feet ............. 5B 5B Infraorbital canal wider than foramen magnum, quills prominent on dorsum and tail ........ Porcupine Erethizontidae

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5B' Infraorbital canal narrower than foramen magnum, quills lacking .................. 5C 5C Tail flattened dorsoventrally, hind feet webbed, cheek teeth each having 10-12 transverse ridges ..... Beaver Castoridae 5C' Tail not flattened dorsoventrally, hind feet not webbed, teeth lacking 10-12 transverse ridges ................................... 5D 5D Upper cheek teeth number more than three, or in Napaeozapus an elongate tail is tipped with white ................... 5E 5D' Upper cheek teeth number three, tail not tipped with white ................................ ....................... Rats and mice Muridae 5E Postorbital processes absent, tail long and scaly, hind feet elongate ..................... .................... Jumping mice Zapodidae 5E' Postorbital processes present, tail fairly long to elongate and always well-haired or bushy ................ Squirrels Sciuridae 6 Fur on dorsum short and felt-like, zygoma lacking or exceedingly slender, premaxillary-maxillary suture fused and indistinct or if present manus is much larger than hind foot ...... Order Insectivora 6A Manus larger than hind foot, zygoma slender ........................ Moles Talpidae 6A' Manus smaller than pes, zygoma lacking ............................... Shrews Soricidae 6' Fur long on dorsum, especially guard hairs, zygoma deep and functional as origin of masseter muscle, premaxillarymaxillary suture distinct, and canine tooth prominent and anteriormost in the maxillary bone ................. Order Carnivora 6'A Four toes on hind foot ................... 6B 6B Only one upper (vestigial) molar present on each side, retractible claws, five toes on front foot .................... Cats Felidae 6B' More than one upper molar present, claws never retractible, four functional toes on front foot .......... Dogs Canidae 6'A' Five toes on each hind foot ............ 6C 6C Cheek teeth bunodont, carnassials not adapted to shearing ....................... 6D 6D Tail long, annulated, only two lower molars, head of head and body less than 41

inches (= 1027 mm) ........................... ........................ Raccoon Procyonidae 6D' Tail short, never annulated, three lower molars present, length of head and body exceeds 42 inches ........... Bear Ursidae 6C' Cheek teeth not bunodont, carnassials adapted for shearing ........... Mustelidae

On mammalian biodiversity “There are several definitions of biodiversity. One is qualitative—the variety of life forms, the ecological roles they perform, and the genetic diversity . . . An-

other is quantitative—the number of species in a specified region, or species richness.” — Robert S. Hoffmann. . . . The Value of Abundance, Western Wildlands, 1991.

Wisconsin has been blessed with both a grand variety of mammals, from pygmy shrews to bears and moose, from the primitive opossum to the incredible star-nosed mole, and, of course, the courageous and fossorial badger. Especially along the “tension zone” between boreal and southern forms, there is a fantastic richness of species coexisting together so long as humans permit.

Photo of opossum Didelphis virginiana. By John E. Long

KEY TO ORDERS AND FAMILIES OF WISCONSIN MAMMALS

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TAXONOMIC ACCOUNTS OF MAMMALS OF WISCONSIN ARRANGED IN ORDERS, FAMILIES, GENERA, SPECIES AND RACES “One of the marvels of early Wisconsin was the Round River, a river that flowed into itself, and thus sped around and around in a never-ending circuit. Paul Bunyan discovered it.... Wisconsin not only had a Round River, Wisconsin is one. The current is the stream of energy which flows out of the soil [and sun] into plants, thence into animals, thence back into the soil.... Ecology is destined to be the lore of Round River. Diversity [of plants and animals] means a food chain aimed to harmonize the wild and the tame in stability, productivity, and beauty.” — Aldo Leopold, Round River, 1953.

Order MARSUPIALIA The Marsupialia is one of the most ancient groups of extant mammals. In earlier ages it inhabited all the major continents, but today it is confined to the Americas and the Australian region. The marsupials are mammals known by their marsupium, a pouch in which the female carries and protects her young. However, other mammals have pouches, and some marsupials lack them. No other mammals in North America have “epipubic bones”, also called “marsupial bones”, one attached to each pubic bone. Marsupials are grouped because of common ancestry in an ancient lineage. They show much adaptive radiation, and taxonomists have split the group into subgroupings that are problematic and subjective. Many taxonomists today regard marsupials as a superorder, or even a cohort, comprised of several subgroupings formerly known as families considered to be orders themselves. One such is Didelphimorphia. Didelphidae, including the Wisconsin opossum, have been included with thylacines and other Australian marsupials. Such submarsupial categories (orders, or suborders)

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include the “order” Polyprotodontia Kirsch, or a quite different grouping, Marsupicarnivora Ride. American Didelphids do not properly belong to any grouping of Australian marsupials, nor even with the South American Microbotheriidae (tiny Dromiciops australis) from Chile (unless this little family is ancestral or nearly so to American marsupials on the one hand and to all Australian marsupials branching off the line separately). A possibility might be that Dromiciops is separate from both American and Australian assemblages. All the American opossums, Didelphidae, seem allied by foot morphology, biochemical resemblances, and sperm-pairs (except little Dromiciops). Marshall et al. (1990) placed this little marsupial in a separate “order” Microbiotheria. This arrangement is not much different from the classical classification (of George Gaylord Simpson), of a marsupial superfamily Didelphoidea containing Didelphidae and Microbiotheriidae.

Family DIDELPHIDAE Gray The fossil record reveals that marsupials were generally replaced on one continent after another by the advent of modern placental mammals (which all have villi rooting the chorioallantoic placenta into the flesh of the uterus). The Didelphidae has become an exception to this geographic replacement, having successfully invaded (or reinvaded) North America af-

Opossum woodcut. [J. G.] Wood’s Nat. Hist. 1880’s.

ter the Pliocene Epoch. This American family, existing since the Cretaceous Time Period in North America, shows little evolutionary change for some 70,000,000 years of evolution. Didelphis virginiana is the only marsupial species found in the temperate habitats of the United States and southern Canada. It is still expanding its range northward from its South American origin (Gardner, 1982).

the state of Virginia. R. H. Baker (1983), quoted the early settler John Smith’s note that “opossum” is derived, from the Algonquian “apasum.” The name Didelphis marsupialis, formerly applied to this species, is now restricted to the Central American opossum (Gardner, 1973), which differs significantly from our species in chromosomal pattern (fundamental number 20 instead of 32).

Genus Didelphis Linnaeus Opossums

Didelphis virginiana virginiana Kerr

“The brain ... indicated by the structure of the skull is remarkable for the proportionately large size of

1792. Didelphis virginiana.The animal kingdom... p. 193. Type locality Virginia. 1952. Didelphis marsupialis virginiana: Hall and

the olfactory lobes, and the small size of the cerebral hemispheres; these contracted in front and destitute of convolutions. As compared with the

Kelson. Univ. Kansas Publ., Mus. Nat. Hist.,5: 322. 1961. Didelphis marsupialis virginiana: Jackson,

brain of the Mammalia ... the opossum furnishes the most remarkable contrast in its small size in proportion to the bulk of the animal. [However] ... the young return to the pouch to suckle and when danger threatens. During this time the female ... will suffer any torture rather than permit the pouch to be opened.” — G. B. Waterhouse, 1848, Natural History of the Mammalia, Vol. 1.

The description for the genus in Wisconsin is written in the description for the subspecies Didelphis virginiana virginiana Kerr (see below).

Didelphis virginiana Kerr Virginia Opossum The name Didelphis was proposed by Linnaeus. The word, literally “double love”, possibly means two penises, for the penis is forked. There are also two uteri, which is what the Greek Dis + Delphus means according to Waterhouse (1848). The name doubtfully refers to the double womb in time, i.e., an internal one for the embryos and an external pouch in which undeveloped young are nourished following birth. The name virginiana refers to

Mammals of Wisconsin, p.17.

Both of the aforementioned species names have been used by numerous Wisconsin workers. Description. The opossum is about the size of a house cat, muzzle slender, eyes conspicuous and dark, fur shaggy and grayish, paler below where guard hairs are sparse, ears rounded and paper thin, tail scaly (with clusters of ancient tactile hairs called “Dreiartgruppen” projecting outward from among the scales), large toe (hallux) on hind foot thumblike, set apart from other toes (opposing them) and lacking a claw or nail. The plantar surfaces show friction ridges for climbing. Skull with prominent sagittal crest, small braincase, numerous incisors (5/4 = 18), prominent canines, and tribosphenic (trituberculate) molars. The nasal bones widen posteriorly. There are two pairs of palatine vacuities. No other Wisconsin species has marsupial (epipubic) bones on the pelvic girdle, nor a marsupium in the female. There are five toes on each foot. Males possess a pendulous prepenile scrotum, and a urogenital sinus connects to the rectum in either sex. There are anal scent glands in the rectum used for defense. The paired vaginae TAXONOMIC ACCOUNTS / ORDER MARSUPIALIA

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Opossum’s left hind foot. After Jackson.

Photo of mother and four young riding in the dorsal fur. F. M. Blake & J. Spero. Some deny that this happens.

combine as one that opens into the urogenital sinus distally and at the other end, near the time of birth, to a temporary birth canal for the young. In males and females the urogenital sinus and rectum although separate are surrounded by a common sphincter muscle. There are sweat glands on the feet and tail. Chromosomes number 2N = 22, the Y small, the fundamental number (i.e., containing elements of biarmed and acrocentric chromosomes) is 32 (Gardner, 1973). Fur in the opossum is grayish, but some specimens are white, dark brown, or even

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Skull of opossum.

blackish. A typical fur is mottled gray and whitish, the face whitish and feet blackish (with white toes). The eye-ring, eyes, and the inner surface of each ear flap are black. Yellowish stains on the chest (from skin glands) are seen in males. A winter-killed albino was found in Stevens Point. Hartman(1952) called this color phase “albinotic” because the eyes are black. Although Jackson (1961) mentioned that females are larger, Gardner (1973) found males are significantly larger, in 11 measurements. Hamilton (1958) found males about 32 percent heavier. Some standard measurements vary from a mean 24-35 in (609-900 mm) for total length, tail length 10-15 in (approximately 242-381 mm), hind foot 2-3 in (50-76 mm), and ear length about 2 in (4050 mm). The greatest length of the skull varies from 80-127 mm, and weights from 4 to 15 pounds (1.8-6.8 kg). Weights reported from nearby states are given in the table Mar1. A 14-pound old male would be exceptionally large. About a third and even more of the weight may be stored body fat, to endure the winter. Cleven (1988) gives the length as up to 36 inches (92 cm), with weights to 12 pounds (5.5 kg), and females up to seven pounds (3.2 kg). Dental formula. I 5/4, C 1/1, P 3/3, M 4/4 = 50. Young opossums may have unerupted teeth. The four molars above are primitive trigons, the lower trigonids each has a talonid heel.

Geographic Range. The opossum is to be expected now throughout most of the state. It is not found on offshore islands in Lake Michigan and Lake Superior. On the Door Peninsula it has been found only in recent years from north of the canal at Sturgeon Bay. See Map. Status. According to Jackson (1961) the opossum was known as early as the 1850’s in southern Wisconsin. It began rapidly expanding its range northward in the early 1920’s, possibly with the opening up of the North Woods (by the extensions of roadways, cutting of timber, etc.). Most records prior to 1961, and since then, are from southern

Maps showing geographic distribution of the Opossum in Wisconsin & North America.

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counties. Since 1965, specimens in the University of Wisconsin-Stevens Point museum, a few from northern counties where no opossums were reported, permitted a crude, singular estimate of the rateof dispersion (Long and Copes, 1968). Other range extensions for the Upper Peninsula have been reported (Baker, 1983), some that invite the question whether the estimated rate as calculated was correct. However, in the sample used by Long and Copes the dispersion was measured point by point, representing new arrivals (according to people that lived in those areas). The rates measured in two separate estimates were a little more than four miles per year, in a northward direction. Other records from the eastern counties and in Upper Michigan may be pioneers in a different advance. Along Lake Michigan, where frost is less severe, and opossums are spared some of the frostbite of tails and ears so common in central Wisconsin, the opossum invaded Upper Michigan even faster than at the rate measured in central Wisconsin. Smith (1988) recently reported three separate records a little northward in Delta County, Michigan (1986-1987). Almost directly north of Menominee County, penetrating wilderness all the way to Lake Superior, the opossum was reported in 1984, on Highway 41 at Marquette, only 1 km from

Table Mar-1. Some weights (kg) of opossums from nearby states, based on data in Brocke (1970), Hamilton (1958), Blumenthal and Kirkland (1976), Wiseman and Hendrickson (1950), Pippitt (1976), and Lindsay (1960). Compiled by Gardner (1982). Location

N & Sex

Michigan

40 M 12 F 83 M 60 F 10 M 18 F 5M 10 F 9M 7F 11 M

New York Pennsylvania Iowa Illinois Indiana

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Mean & Range 3.6 2.4 2.8 1.9 3.4 2.4 3.1 1.8-3.1 3.8 2.4


2.8-4.6 2.0-3.2

2.2-4.0 1.8-3.1

1.7-5.9 1.8-3.1 5.4

Lake Superior (Robinson and Heitman, 1986). By 1996, opossums had advanced in western Wisconsin northward as far as Luck, Wisconsin. Another advance is to 9 mi. E Fifield, in Price County (4 Nov. 1996). Recently (2005) it extended the known range to northwestern Douglas County (see Records, Ron Parmela). The opossum is more than a curiosity of nature, our only Wisconsin marsupial, because its food habaits involve numerous food webs in our ecosystems. For one thing, it eats many harmful insects. It also cleans up much carrion. It has some fur value. On rare occasions it has killed domestic chickens. But today domestic chickens are seldom kept outside or even in outside pens. In Wisconsin, the opossum is not legally protected. However, hunting and trapping for it and other furbearers are allowed only in late autumn or winter. Although the flesh is edible, and savored in some areas of the southern United States, and the fur is fairly luxurious, not many are harvested and the pelt price is low (compared to other furbearers). In 1935-1943, the highest harvests of this species in America exceeded 2,300,000 pelts, but peaks dropped off to about 150,000 in 1958-9 (Deems and Pursley 1978). The opossum builds a nest of leaves in a hollow snag, a crevice, in farm buildings, or even brushpiles. It may carry bundles of leaves to its nest in its prehensile tail. It usually spends the winter in a burrow, often one abandoned by a striped skunk. In its wanderings it may use many dens for day resting, often only a day. Foods. Opossums are omnivorous, and feed on a wide variety of insects, other invertebrates, mice, birds, worms, eggs, seeds, berries, soft fruits of plants, and even shoots or leaves. They have varied fare of carrion (especially rabbits, and including other dead road-killed opossums). Knudsen and Hale (1970) examined the stomachs of 151 Wisconsin opossums from all months of the year, and reported 65 different foods. See Table Mar-2 for seasonal use. Mammals comprised

Table Mar-2. Seasonal use of important opossum foods (values based on 5 percent of occurrences) studied in southern Wisconsin, 1953-1958.

Food Earthworms Insects Mice Songbirds Cottontail Frogs Garbage Snakes Apples Chicken

Winter

Spring

Summer

Fall

— 14 23 6 29 3 16 — 6 10

31 11 17 19 9 10 9 10 6 4

54 29 4 25 — 25 4 13 4 13

35 31 19 15 19 12 — 8 15 —

After Knudsen and Hale, 1970.

25% occurrence of the diet and 41% by weight. Most of the animals were decayed carrion. Earthworms, insects, songbirds, frogs, snakes and chickens were common summer foods. Other foods included cottontails, shrews, moles, squirrels, muskrat, Norway rat, dogs and cats, even swine, bobwhite, ducks, pheasant, pigeon, screech owl, crow, crayfish, snails, even fishes, apples, other fruits, grains, vegetables, mast, and garbage. The most amazing food is venomous pit viper snakes, which cause no harm to opossums even when snake bites are successful and fangs eject their poison (Gardner, 1982, Kilmon,1976, and Werner and Vick, 1977). Reproduction. Opossums reportedly mate lying side by side, by means of a bifid penis inserted into the female’s vagina. Copulation is brief. Mating begins as early as January in northern states, but usually peaks later in March. Gestation is no longer than 13 days. The litter of partially developed young may number as high as 22 or 25, but usually 18 or less. A late litter was observed on 18 July, 1993, in northern Door County. These naked young were only 35-37 mm in crownrump length. After birth, the reddish, naked, undeveloped young (length approximately 13 mm, weight 0.13 g) clamber quickly from the opening of the vagina anteriorly to the pouch, swinging their heads from side to side, eyes

unopened, crawling overhand like swimmers through the fur for a distance of approximately 3 inches (76 mm) (Hartman, 1920). Inside the pouch they each seize a nipple and hang on. Usually there are 13 nipples, as many as 17, in a horseshoe pattern. Not all the anterior nipples may produce milk, but approximately 11, and sometimes 12 or 13 young become attached. The number of young that survive is usually limited to only 7 or 8. For several days, if the young is detached from the nipple, it attempts again to seize a nipple. After three days the expansion of the distal nipple anchors the offspsring for some 50 to 60 days. The young weighs less than half a gram after several days. Thus, the mother’s nipple elongates during the period of lactation, and expands distally to help keep the young attached until they grow larger. When detached from older offspring, the elongated nipple facilitates nursing outside the pouch. After 60 to 70 days, when the young weigh about 25 g each, they leave the pouch occasionally, returning for milk and shelter until weaning. The young stay with the mother as long as 3-4 months. Weaning is completed at approximately 90-100 days. The mother calls her offspring by a clicking noise, similar to that of the male as he pursues a female. Often the opossum leaves her young in the den to forage for food. It is often said emphatically little opossums do not cling to the mother’s fur, but see Fig., also Hamilton, 1939: fig. 59). Females may breed at six months of age. Young males also might breed the first year. Most opossums breed first as yearlings. They seldom live beyond 2 years; some apparently live four. Opossums show a progressive irruption of the dentition. Behind the canines the premolars and molars erupt roughly in this sequence: At 3 months, dp 2/2, M 0/0; at 4 months 3/ 3, 1/2; at 5-8.5 months, 3/3, 2/3; from 7-11 months, 3/3, 3/4; about 10 months or older, 3/3, 4/4 (the full adult complement) (see Gardner 1952). Mature opossums show tooth wear on the anterior molars before showing wear on TAXONOMIC ACCOUNTS / ORDER MARSUPIALIA

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all of them. Growth of the young is fairly regular (almost linear) the first year, by which time sexual maturity is attained. Mortality. Cars in Wisconsin kill innumerable opossums. Dogs hunt them, hounds trailing them at night and often treeing them so hunters may shoot them. Trappers take them for their fur. Coyotes, foxes, badgers (probably), and great horned owls feed on them (Jackson 1961). The chief enemies are people, dogs, and automobiles, and long, cold winters (especially in underweight juveniles, less than 1400 g each, Gardner, 1982). Seidensticker et al. (1987) mention in this order, weather, nutrition, and disease, with natural enemies owls, hawks, coyotes, domestic dogs, raccoons, bobcats and some large snakes (on young opossums). Statistics given were cars (35%), parasites (17%), winter freezing (9 %), only 4 % due to trapping, and 35% unknown. Jackson (1961) listed diseases and parasites including tularemia, ticks (Dermacentor usually), fleas, and internal worms (Physaloptera usually). Rabies virus can infect opossums, but usually there is little incidence. Several arboviruses infect opossums and could pose a threat to other animals. Karl E. Shewmake, M.D., told this writer (1999) that opossums present a problem as a carrier of a virus (called EPM) that causes a polio-like disease in horses in Wisconsin. It does not infect humans, and is transmitted by opossum feces. Horses eat the fecal material with meadow grass or in hay, but are more likely to eat it mixed with horse food when the two mammals share the food trough. Spotted fever, plague or tuberculosis organisms may infect opossums. Other diseases are listed in Addison et al. (1987) and Barr (1963). Home range and Density. In Wisconsin, Cleven (1988) mentioned home range of the opossum as 20 to 40 acres (= 8-16 ha). Hunsaker reported home ranges up to 20 ha. Gillette (1980) studied radio-tagged opossums in the warm seasons and found that the males wandered on average some 270 acres (108 ha). The home range for females was 127 acres

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(51 ha). Younger or nonresident individuals wander long distances, as far as 7 miles (11.2 km) in Missouri (Reynolds, 1945). Through one winter month (January, 1996) I observed one old opossum (until it disappeared) that wandered nightly, within an area of no more than 2 acres. Males have larger ranges than females, and juveniles smaller than either. Population density is known to be as high as one opossum per hectare in Illinois (Stieglitz and Klimstra 1962). Hunsaker (1977) found density to be 0.26 / ha (0.2-1.16 / ha). Opossums seldom live longer than 2-4 years, but in captivity one lived six (Baker 1983). In a land so cold that the ears and tail freeze, the longevity is short (only 3-4 years according to Crandall, 1964), and the intelligence of the animal questionable, then, when all things are considered, it is surprising that opossums are expanding range. Remarks. Hair from the fur of opossums is used as nesting material by white-footed mice and chickadees. Titmice were observed pulling hairs from a live opossum (Packard, 1949). Small opossums hole up during freezing weather, but those larger than 4 kg changed dens and moved about even then (Pippitt 1976). In winter the opossum sleeps a lot in its more permanent winter den, but its body temperature does not appreciably drop. Year round, it varies 32-38 degrees C, and thermoregulation begins at 55 days (completed at 94 days). Opossums use their scaly, prehensile tail not only to clamber about in trees, but to curl it around clumps of leaves to transport them to their nests (dens). “Playing ‘possum,” of course, is feigning death, mouth gaping, body limp and prostate, a physiologically comatose state. I have seen it in a young opossum, after it was attacked by our dog. Males make an open-mouthed threat in encounters, screeching and weaving from side to side, fighting, and even killing the opponent on occasion. Females also gape and show agonistic threats to other adults, but aggression ceases if the female is receptive to mating. Such attitudes ensure a rather solitary life,

with opossums often avoiding one another. Noises include clicking, growls, hissing, and in anger a loud screech. McManus (1974) reviews opossum behavior. Additional Natural History. Hartman (1952), McManus (1974), and Gardner (1982) reviewed natural history for the opossum. Geographic Variation. There is only one race in Wisconsin. Specimens examined. Total, 55. Adams, Brown, Dane, Dodge, Door, Douglas*, Green, Jefferson, Juneau, Kenosha, Kewaunee, Manitowoc, Milwaukee, Monroe, Oneida, Polk, Portage, Price, Racine, Richland, Rock, Sheboygan, Trempealeau, Vernon, Washington, Waukesha, Waupaca, Winnebago counties. Other Records. Jackson (1961) examined 9 specimens from Wisconsin. Sauk Co.: Leopold’s shack (Mossman, 1980, not mapped). Michigan. Robinson and Heitman (1986) “On Hwy 41” at Marquette, 1 km from Lake Superior. 1984. Roadkills between Marinette and Escanabe.

Order INSECTIVORA The Insectivores “In the dark and cold embrace of Mother Earth, away from the cheering sunlight and the beautiful upper world that we enjoy, there dwells a group of mammals so strange and yet so useful to man, that they excite our admiration.... Pass not unthinkingly the moles and shrews, for they have been most cunningly designed to serve a definite and important function in the economy of nature.”— W. T. Hornaday, in The American Natural History, 1904.

The order Insectivora, as old as Cretaceous Period, is found on all continents except Australia. These some 400 species are comprised of medium-sized to tiny mammals having elongate and pointed snouts, small eyes, * Hwy 13, Amnicon R., sect.10, May 9, 2006. Roadkill reported by R. Perala.

primitive ears (lacking much or all of the entotympanic and much of the ear pinna), the genitalia and anus are in close proximity (almost resembling the cloaca of monotremes), and five toes are on each foot. The zygomata are absent in shrews, and slender in moles. The antemolar tooth-rows are divergent posteriorly, and the cheek teeth are typically dilambodont (W-shaped). The anterior teeth are procumbent, i.e., scalpal-like or forcepslike, on the one hand, or are tiny incisiform teeth and caniniform teeth, on the other. The fur is short and felt-like in the shrews, and soft and fleecy in the moles. Although some shrews, and all moles, have white teeth, the shrews of Wisconsin show chestnut-brown tips, which more specifically tend to comprise an outer layer made of several sublayers, the outermost brownish. Each lower, anteriormost tooth has almost a straight-edged brownish outer wall enclosing the inner, elongated white enamel crown, with humps of red-brown in tandem in some species analogous to cusps, and in Sorex arcticus showing anteriorly even an inner brown tipping on one hump. In these teeth, Blarina and Cryptotis have nearly straight-sided red-brownish walls. They show, as does Microsorex, accessory cuspules on the upper “unicusps”. The terms unicuspid, unicusp, even unicuspate are not technically correct for such shrews. The Wisconsin insectivores belong to a distinctive suborder Lipotyphla. The other suborder Menotyphla includes the African jumping shrews and the Tupaiidae (except some workers, including myself, assign Tupaiidae or tree shrews to the order Primates). In shrews W-shaped ectolophs are conspicuous. In moles, not far removed from the ancestral insectivoran Leptictid pattern, the ectolophs are said to be W-shaped. Moles seem primitive in molar pattern, retain a slender zygoma, are about the same as shrews in construction of their auditory bulla (some have the bulla complete by addition of an entotypanic expansion), and the dentition of Condylura has the primitive number of teeth (44). Therefore, moles are discussed TAXONOMIC ACCOUNTS / ORDER INSECTIVORA

75

before shrews, which is not conventional, but in line with evolution of tiny size in shrews.

Key to Families of Wisconsin Insectivores 1

1’

Size larger (total length exceeds 150 mm, weight more than 30 g), external ear pinnae lacking, forefeet broad, twice the width of hind feet, zygomata slender but always present, teeth exceeding 2 in number ...................... Talpidae, Moles Size smaller (total length less than 150 mm, weight less than 30g), external ear pinnae inconspicuous but present, forefeet small, hardly wider than hind feet, zygomata lacking, teeth 32 in number or fewer .................. Soricidae, Shrews

Family TALPIDAE Fischer Moles “These beasts are all blind... and therefore came the proverb, Talpa caecior tuphlotaeros alpalacos, blinder than a Mole; to signifie a man without judgment... yet if any man look where the eies should grow he shall perceive a little passage, [and] by drawing up the little skinne... therefore of them. — Topsell, Historie of foure footed beastes, London, 1607.

Chief characters are summarized in the Key above. These fossorial mammals feed mostly on earthworms (Oligochaeta) and beetle nymphs.

Key to Wisconsin Moles 1

76

Twenty-two tentacles surround nosepad (rhinarium), anteriormost upper teeth spoon-like, elongate tail tapered at anterior and posterior ends ....................... ................................. Star-nosed mole Condylura cristata THE WILD MAMMALS OF WISCONSIN

1’

Snout devoid of tentacles, anteriomost upper teeth elongate, chisel-like and robust, tail short and not tapered ............ ...................... Eastern or Prairie mole Scalopus aquaticus

Genus Condylura Illiger Star-nosed Mole Condylura cristata cristata (Linnaeus) 1758. Sorex cristatus Linnaeus. Systema Naturae, ed. 10. Vol. 1, p. 53. 1819. Condylura cristata: Desmarest. J. de Phys., Chim., Hist. Nat., et des Arts. 89:230.

The name Condylura Illiger, 1811, is Greek, and means knobbed tail based on a faulty drawing by De la Faille. Linnaeus provided the name cristata, which means little crest, and is often featured in moles. External measurements are given in Table Ins-1. Dental Formula. DF = I 3/3, C 1/1, P 4/4, M3/3 = 44, the so-called primitive number of placental mammals. Howard Whidden (personal communication) informs me the genus is known in the Pliocene of Poland, supporting my view that the mole is primitive. Some premolars are triconodont (3 cusps aligned) and do not occlude with their analogs in the opposite jaw. The canines are caniniform, which is not always the case in moles. The I 2/ is so minute it may be obscure (see skull fig.).attributed to a peculiar sagittal ridge, but much more likely refers to the rosy-pink cluster of tentacles on the snout. In Latin, crista also means a tuft on the head. This corona of 22 bilaterally arranged tentacles, tactile in function, provides a basis for the name “star-nosed mole.” Description. This mole has the typically broad hands with robust claws characteristic of moles. They are narrower than in the Eastern mole Scalopus. The star-nosed mole is readily identified by the 22 pinkish or gray (in dried skins) tentacles surrounding the two

Musculature and tendon structure of the nasal rays of Condylura. After Grand et al. 1998.

nostrils, and a long, sparsely haired, fleshy tail (tapered at either end). The eyes are small, auricular openings prominent, feet have scales, and 5 toes are on each foot. The fur is relatively coarse for a mole, dense and long, with a softer underfur. Molts occur in June and October, when winter fur is attained. The skull is long and narrow, zygomata short and slender, jaws narrow with widely-spaced (sawlike) antemolar teeth, molars mostly W-shaped with interior portion a shelf, premolars somewhat tricuspate, lower molars similar to upper molars, but portion a shelf, premolars somewhat tricuspate, M-shaped, auditory bullae incomplete. Chromosomes number 34, with a fundamental number of 64 (Petersen and Yates, 1980). The karyotype is much different than in other moles. The star-nosed mole is nearly black dorsally, the venter a paler blackish brown, tail, feet and head concolor with body. The wrists are tan. Worn pelages are browner or grayer. The sexes are similar in size, unusual in moles. External measurements are given in Table Ins-1.

Skull of the star-nosed mole.

Geographic Range. The star-nosed mole dwells in northern Wisconsin and Upper Michigan, restricted from most islands in Lake Michigan, and apparently from the Door Peninsula. Status. Condylura is uncommon, restricted to wet, boreal soils of swamps and stream valleys in northern counties. The status seems unchanged from the turn of the century, although the loss of wetlands and application of pesticides probably had an adverse effect. The soils where this mole dwells are usually too wet for agriculture or building, and this animal is seldom a nuisance. Habitats. This semi-aquatic mole is found in black, wet soils, mucky humus, or sandy loam, of stream and river valleys, swamps, lake shores, and marshes mostly of northern counties. Occasionally it lives in lawns near water, in cedars, spruce, tamaracks, birches, alders, jewelweed, marsh grasses, and sedges, often in association with jumping mice and shrews. I have taken this mole (2) and Blarina (2) from the same partially flooded tunnel (Jordan Marsh, Portage County) on alternative nights. Don Follen, Sr., trapped two Blarina and two Condylura sharing the same tunnel (Oct. 16-28, 1967) near Arpin, Wood County. Condylura swims under ice and moves about on snow (Jackson 1961; also see photo). Star-nosed moles tunnel less extensively than the prairie mole Scalopus, and the ridges are usually less than two inches wide. Where surplus dirt is mounded up, in wet globs TAXONOMIC ACCOUNTS / ORDER INSECTIVORA

77

and layers, the mole hill may extend above the vegetation to a height of six inches, and may be as much as two feet wide. In a series of mole hills found in farmyards in eastern Wood County, the huge hills resembled those of Scalopus. Small trails, almost trenched runways, extended on the soil surface to a small intermittent ditch of water. The nest is a loose wad of leaves, grass, or both, constructed in an ovate chamber nearly seven inches in diameter and three to five inches in height. The nest has been observed sited between tree roots and under a decayed stump. Audubon (Audubon and Bachman, 1842-

78

Maps showing geographic distribution of Condylura cristata in Wisconsin and North America.


1846) found one made of withered grasses in an excavation under a stump to which a tunnel was excavated. The nest is usually three to ten inches underground. As many as three tunnels enter the nest; each is about 40-50 mm in diameter. Young have been found in the nest (Jackson, 1961; Schmidt, 1931; Audubon, loc. cit.; Rust, 1966). Foods. Star-nosed moles feed mostly on terrestrial and aquatic worms, insects, other invertebrates, and to a lesser extent aquatic vertebrates (frogs, fishes) (see Jackson, 1961). Don Follen found earthworms in a Wood County mole’s stomach (October, 1967). One kept in captivity was fed earthworms in a bowl of water daily. The mole dived in swimming about beneath the surface with its tentacles actively searching. When the worm was encountered the male seized it, carried it from the water to a corner of the aquarium, and noisily ate it. A plastic bass bait closely resembling a worm was never seized by the swimming mole unless the plastic worm was rubbed with a live worm, whereupon the mole seized the bait and carried it out of the water. One could hear gnashing of tiny teeth, suggesting that somehow the mole had tasted the juices of the live worm. Whether the tentacles function in the tasting is unknown, for no one has ever searched for taste buds in the tentacles. Possibly the tongue is used in tasting the surface of a prey animal that was detected with the tentacles. Gould et al. (1993) described a new function of the oral tentacles, as electroreceptors.. This new sense was unknown in mammals except for its recent discovery in the Australian platypus (Ornithorhynchos anatinus). Gould et al. found attacks of moles correlated with specific parts of the worms, especially the clitellum, where electroactivity from secretions was measured as particularly strong. Other electrical “hot spots” were likewise selected as targets by the moles. Data from electrified fields in tunnel-mazes suggested electroreception in the oral rays. Moles even selected simulated worm fields of elec-

tricity over non-electrical areas. Whether the Eimer’s organs, small tactile sensory organs on the tentacles, are responsible for this sixth sense is not clearly stated, but Gould et al. suggest there is a great density of these organ -receptors around the center of each set (of eleven) rays. They suggest the disparate size of the rays enhances sensory or electrical perception. Catanla et al. (1993) identified “stripes” on each side of the neopallium of Condylura, which areas apparently have evolved for the special afferent impulses from each set of eleven rays. Taken altogether the evidence supports an explanation of an amazing electromechanical sense in Condylura used to detect prey and to explore surfaces, such as the water surface. There are some students of moles who are unconvinced. No one doubts that this mole has some sort of incredible sense (taste?) for detecting worms. Reproduction. Jackson (1961) suggests the adult star-nosed moles that pair in autumn may mate, but probably not until winter. Males apparently breed in February to mid-March. Gestation is believed about 45 days. Breeding reportedly extends from mid-March through April. There are usually six young, but the number may vary from 3-7. Eadie and

Condylura cristata from Portage County.

TAXONOMIC ACCOUNTS / ORDER INSECTIVORA

79

Hamilton (1956) found a mean litter size of 5.4. There are eight mammae. Naked and blind at birth, the young are pinkish and only the vibrissae are visible hairs. Partially developed tentacles are obvious even in developing embryos. Newborn young are remarkably large, reportedly measuring 70-75 mm including the tail (25 mm). The young are born in late April to mid-June (which may account for the paucity of breeding records, because little field work is carried out in the North Woods until winter’s end). There is but one litter per year. In six to eight days short fur appears dorsally, and in two days more the abdomen is haired. When the young leave the nest at about one month or more of age their sleek fur covers the body. They each weigh about 30 grams. Mrs. John Pollock of Rhinelander found five young in a nest on May 3, 1932 (Jackson 1961). Alan Long caught one by hand weighing only 20 g, in Whiting, Wisconsin, in early July. This mole may have been born in early June. Although small it was well furred (see Table Ins-1). The teeth erupt before the young moles leave the nest. Jackson (1961) mentions a small sagittal crest appearing in old adults. Small moles in this collection yield measurements given in Table Ins-1. Mortality. Carnivores that prey on starnosed moles, usually catching them above ground, are dogs, red foxes, fishers, striped skunks, and house cats (Hamilton 1936, Murie 1936, Schmidt 1931, Timm 1975, Toner 1956). Aquatic predators include large-mouth bass, bullfrog, and mink (Christian 1977, Pine 1975). Mike Eber told me a northern pike ate a star-nosed mole in Monroe County. Hawks and owls take them (see Baker 1983) and even the great gray owl (3 specimens in this collection are from owl pellets from Ashland County). Ticks, mites, fleas, tapeworms, and roundworms parasitize this mole (Hamilton 1931, Jameson 1949, Scharf and Stewart 1980, Timm 1975, Yates et al. 1979). Home Range and Density. Jackson (1961) thought as many as 30/ acre might

80


be found in ideal habitat. These concentrations are likely family groups, and some have doubted that the density is so great. In central Wisconsin I have taken several together, suggesting about 3-4 per acre, and nearby none at all were trapped. In their wanderings by use of water (they even swim under ice) and tunnels in the snow they may disperse from one habitat to another, and often find themselves in some farmer’s yard by access of an ephemeral ditch of water. Remarks. Large star-nosed moles (60 g) consume oxygen at a rate of 4.2-4.5 cc/g/ hr. Juveniles had lower metabolism, about half as much (see Petersen and Yates, 1980). Additional Natural History. Peterson and Yates (1980) reviewed biology for Condylura. Specimens examined. Total, 61. Ashland (Outer Island, Apostle Islands, 1), Bayfield, Brown, Calumet (Kiel, 1), Clark, Dodge, Kewaunee, Jackson, Juneau, Manitowoc (Branch River Country Club, 1, Point Beach State Forest, 1 UW), Marathon, Marinette,

Table Ins-1. External measurements and weights of Condylura from Wisconsin. Specimens selected having weight data on the labels. No.

Locality / Measurements

5971

Drummond 184-75-28 Westboro 168-70-23 Eagle River 179-70-24 Abbotsford 188-76-25 Portage Co. 190-72-21 Wood Co. 176-70-25.5

Sex/ Weights g.

Adults

3795 1005 1753 63 3716

Of Weaning Size 3107 Marinette Co. 77-70-26 3895 Whiting 141-53-25

M 46 M 37.1 M 46.9 M 49 F 42.7 M 45.8 F 30.1g (Oct.6, 1971) ? imm. Estimated wt < 20 g (July 11, 1974)

Head and forefoot of Scalopus. Scratch sketch H. E. Anthony.

Oneida, Portage, Price, Rusk, Sheboygan, Taylor, Vilas, Waupaca, Waushara, and Wood counties. Michigan. Other record. Big Summer Island, Lake Michigan. Schoolcraft Co.: Seney 1 UMinn.

Scalopus E. Geoffroy Saint-Hilaire See Description for Scalopus aquaticus.

Scalopus aquaticus (Linnaeus) Eastern or Prairie Mole Scalopus aquaticus machrinus (Rafinesque) 1832. Talpa machrina Rafinesque. Atlantic Joumal, 1:6 1. Type from Lexington, Kentucky. 1832. Talpa servicea Rafinesque. Atlantic Journal, 1:62. Type from Nicholasville or, Harrodsburg, Ky.

Jackson (1961) and others refer to it as the prairie mole, which is an excellent and meaningful name. Description. The eastern mole is ratsized, stout, with huge hands and enormous foreclaws (used for digging and pushing soil), head short and almost conical, lacking visible ear pinna or conch, and the auricular openings are small. The eyes are tiny, present but suspended in skin, covered with fused eyelids; the snout naked anteriorly with nostrils opening upward; tail short (about one fifth of total length), scantily haired so as to appear naked, feet all with five toes, all webbed, pelage plush (velvety) dense and smooth. The skull has stout, large but slender zygomata, complete auditory bullae, truncated nasals, and anteriormost teeth (probably I 1/) large and directed vertically (almost chisel-like as in rodents). Chromosomes 2N = 34, fundamental number reportedly 64 (Hoffmeister, 1989). The eastern mole is grayish black or brownish black, often washed with a silvery sheen, usually browner in winter, occasionally with an orange or rusty sheen on venter (environmentally caused?). Feet are dirty whitish above, with naked gray skin below. No. UW 2040 taken June 1, 1969, in Crawford County, is an albino. Male eastern moles are slightly but significantly larger than females in most external and cranial measurements. Weights of males are given in Table Ins-2.

1842. Scalops argentatus Audubon and Bachman. J. Acad. Nat. Sci. Philadelphia, 8:292. Type, from southem Michigan. 1905. Scalopus aquaticus machrinus: Elliott. Field Columb. Mus. Publ., 105, Zool. Series, 6:470.

The name Scalopus comes from the Greek Skalops, to dig. The word “aquaticus” means, of course, aquatic, but this is a misnomer because the mole is not aquatic. This is not the only mole found in eastern United States, but it is common and wide spread.

Skull of Scalopus aquaticus.


81

Dental Formula. Reported often as I 3/ 3, C 1/0, P 3/3, M 3/3 = 36. However, there is no way to account for the tiny spicules variably present in the lower antemolar series, nor to know with certainty the serial homology with the upper ones. Some antemolars are spicules either reduced in size in their evolution, or perhaps were retained milk teeth. Consequently, one often observes teeth in excess of 36, and their presumed homology with, for example, Condylura, cannot be confirmed. For practical purposes, the upper series of teeth of the eastern mole can provisionally be regarded as 3, 1, 3, 3. Geographic Range. This prairie mole is confined to the prairie counties of southern and western Wisconsin, ranging to the southern marshes of Portage and Wood counties, and northwest to Burnett County along the west border. See Map. Status. Unchanged since the 19th century. This eastern (or prairie) mole is often a nuisance in lawns, cemeteries, and golf courses. It is beneficial in soil formation and in eating beetle nymphs (grubs). It eats earthworms (of no appreciable or practical loss) and corn seedlings on occasion. Habitats. The eastern mole occurs basically in sandy loams, grasslands, prairies, roadsides, pastures, railroad rights-of-way, lawns, golf courses, cemeteries, and cultivated fields. Hoffmeister (1989) mentioned their occurrence in almost any friable soil in which the moles can push or dig dirt in their tunnels. At the edge of their range in central Wisconsin, the moles seem limited in their northward dispersion by the extensive marshlands, which, after draining by ditches and allowed to develop as prairie (for prairie chicken management in some cases) become suitable for moles. In western Wisconsin the moles are found both in the valleys and on the uplands, often sandy where soil is established on the summits (e.g., at Ellsworth, Wisconsin). The ridges or mole runs of the eastern mole usually are wider than those of the starnosed mole, and the hills larger, wider and

82


more flattened heaps of soil. Often found and confused with pocket gophers, the tunnel ends are not plugged (by pushing soil upward and out), nor are the hills of dirt thrown in some particular direction, but raised upward and spread more in a circular pattern. Such tunnels in the topsoil seem like wrinkles in a lawn, but in winters the tunnels lie deeper where the worms and beetle larvae are more likely to be found. This deeper series of tunnels, reportedly 8 to 24 inches (Jackson 1961) and doubtlessly a great deal deeper in winters of deep frost, is the home of the eastern mole. Jackson reports that this mole digs in lawns 18 feet per hour, and in a night can create a ridge 50 or more yards in length. The nest is about 5-6 inches (127-152 mm) in diameter, usually at a depth of 13 to 18 inches. Sometimes the nest is only 5-6 inches underground. The nest is comprised of grass and rootlets, occasionally of leaves, and at times is practically void of nesting materials. The nest is sited in an ovate chamber about 8 inches long with diameter about 5 inches. Foods. Jackson (1961) and Hisaw (1923) considered the primary foods (80 percent) of the eastern mole to be earthworms, grubs and adult insects. The remainder is plant material. On occasion, snails, centipedes, and millipedes are eaten. Plants include rootlets and seeds, and captive moles feed on a variety of fruits and vegetables (summary in Baker 1983). West (1914) and Whitaker and Schmeltz (1974) found comparable percentages. The season and habitat are important according to West who found moles feeding on carpenter ants, and in May and June on emerging May beetles. One mole caught in winter had eaten 150 ants. Reproduction. Conaway (1959) obtained information from Dane County moles. They breed but once a year, and young-of-the-year do not breed. Breeding commences as early as February or March and continues into April. Gestation is thought to be about 45 days, but may be only one month (Jackson, 1961; Conaway, 1959). No parous females were found

in late March when breeding was at peak. Conaway notes a few pregnancies after 5 May; one was as late as 4 July. The naked young are large at birth (about 50 mm in length). The litter size varies from 1 to 5, usually 4. There is some resorption of embryos. Testes develop rapidly in December, but mating occurs several months later. The young are haired out in about 7-10 days. In about five weeks, the young are more than half the size of their mother (Yates and Schmidly 1978; Jackson 1961, Hoffmeister 1989). Mortality. Eastern moles have few enemies because they so seldom come out above

Maps showing geographic distribution of Scalopus aquaticus in Wisconsin & North America.


83

ground. Hawks and owls eat them on occasion, and foxes, coyotes, and domestic dogs kill them (Arlton 1936, Davis 1951, Wallace 1950, Wilson 1938, Errington 1935, Murie 1936, Schofield 1960, Van Hyning 1931). Often the mole is rejected as food because of its rank odor. Parasites include the louse Euhaematopinus abormis, fleas (Ctenophthalmus and Corypsylla), mites, and intestinal worms (Monoliformis, Filaria, and Spiroptera) (see Jackson 1961, Baker 1983). Home range and Density. Arlton (1936) and Harvey (1976) found home ranges for the eastern mole from 0.86 acres to two acres (0.75 -8.0 ha) and 10.6 ha (for males) or 2.7 ha (for females). Arlton found a branching tunnel system covering an area about 0.35 ha. Moles wander much more extensively than pocket gophers (Yates and Schmidly, 1978). Baker (1983) suggests that 1-2 moles/acre (2-5/ha) are probably normal density. He disputes Jackson’s (1961) estimate of 8-10 per acre. Additional Natural History. Yates and Schmidly (1978) reviewed the biology of Scalopus aquaticus. Geographic Variation. There is a cline (i.e., a gradual change over some wide area) in increasing size northward from Tennessee, but it is not continued into central Wisconsin. That is because the eastern moles in southern Wisconsin are likely recent invaders from the southeast. Specimens examined. Total, 29. Adams, Burnett, Chippewa, Crawford, Dane, Eau Claire, Grant, Iowa, Juneau, Monroe, Portage, Richland, Sauk, Vernon, Waushara, Wood counties.

Other Records. Milwaukee Public Museum records. Pierce, Grant, Columbia, Sauk, Adams, and Buffalo counties. Ellsworth, No specimen (mole hills observed). Nottingham Ridge, No specimens. 2 mi. SW Osseo, also Osseo (No specimens, mole hills observed). Town of Grant, Prairie Chicken Area on Buena Vista Marsh, T21 N, R7E (no specimen, hills observed). Clark (Schmidt, 1931).

Family SORICIDAE Linnaeus Shrews Shrews are small to tiny mammals (including some of the smallest mammals in the world) with conical, elongate and flexible muzzles (or snouts), tiny eyes hardly visible, ear pinnae small but usually evident, front feet smaller than hind feet, tail well-haired with short hairs, each foot having five tiny toes, skull bird-like with ovate braincase and slender rostrum, and zygomatic arch incomplete. Anteriorly it persists as a vestigium, the maxillary process, and the jugal bone is lacking. The anteriormost upper tooth is bicuspate, its lower analog in the dentary remarkably elongated, and usually along each border slightly tetracuspidate. The functional points (apices) of the cusps and crests are usually red-brown unless worn away, the auditory bullae are undeveloped, the tympanic bone ring-like, and the pelage felt-like (short and dense).

Table Ins-2. Body weights of male Scalopus from Wisconsin , after Conaway 1959. Months Adult Adult Adult Juvenile Juvenile

84

March-April May-July August-November6 May-July August-November10

N

Mean

sd

34 27 117.6 28 107.8

121.5 g 120.6 5.15 95.7 10.79

11.35 14.10


8.75

Sorex cinereus and the larger S. palustris. Spencer Fullerton Baird, 1858.

Shrews have high metabolism per gram of body weight. In Blarina the metabolic rate is 3.18 cm 2/g/hr, with heart rate of 740-760/minute, and a body temperature of 38o C. (Doremus 1965, Neal and Lustick 1973). In smaller shrews the metabolic rate per gram of body weight is even higher, highest of all in the pygmy shrews Microsorex (Buckner 1964:260). Animals that have such high metabolism need to eat regularly. In winter they must eat to compensate for loss of body heat because their surface area to mass ratio is high. The dense fur is efficient insulation, but a great deal of protection is afforded the shrews by deep snow in the north (under which the temperature is warmer). Shrews are found in Wisconsin in soils having a high content of moisture (Sasse 1978; Getz 1961d). Sorex arcticus prefers marshes and shrub communities, Blarina brevicauda is at home in grasslands or woodlands, Sorex palustris is restricted to stream banks and wetlands, and Sorex (Microsorex) hoyi is an enigma and, although rare, found in diverse environments. Cryptotis parva is probably eradicated from Wisconsin sandy prairies. How to study shrews. The advent of pitfall trapping, i.e., sinking empty 1/2 or 1 gallon cans into soil (the rim flush with the soil surface, soil packed closely against it) in a variety of natural habitats (punching holes in the bottoms in wet soils so the cans will not float up) has led to greatly increased catches of the rarest and tiniest shrews. It is possible to obtain density data, distributional data, and of course, more information on embryo counts, parasites, and so on. By checking the cans regularly in the night, and leaving food in the cans (insects, worms, canned dog food), it is possible to capture shrews alive. That could lead to capture-recapture information if marked shrews are released. A wonderful opportunity exists to keep the rare shrews alive in large enclosures with natural soils and native vegetation.

Key to Wisconsin Species Of Shrews Note: Sorex fumeus ought to be confirmed, an unlikely member of the Wisconsin fauna, and it is not treated herein. The locality of Racine may as well refer to the home of the collector Hoy as to the shrew. It resembles Sorex cinereus, but is recognized by dark underparts, flattened braincase truncated posteriorly, and inner lophs of unicuspate teeth less pigmented. The skull is longer than 17.5 mm. 1

1’

2

2’

3 3’ 4

4’

Tail short relative to the body length, less than 30 mm (1 1/4 in), more than a third of the total length, external ear conch hidden in the fur of the head ............. 2 Tail long relative to the body length, more than 30 mm and more than a third of the total length,ear pinna tiny but visible ....................................................... 3 Size larger (head and body more than 90 mm), tail 18-30 mm, mature skull exceeds 23.0 in length, 5 unicuspate teeth ............... Northern Short-tailed Shrew Blarina brevicauda Size small, about 90 mm or less in head and body length, skull much less than 20 mm, 4 unicuspate teeth .... Least shrew Cryptotis parva Third unicuspate tooth smaller than fourth .............................................. 4 Third unicuspate tooth larger than fourth ....................................................... 5 Size larger, total length 131 or more, pelage dark blackish or slate-gray dorsally, hind feet fringed with hairs, third unicuspate tooth somewhat smaller than fourth ...................................... Water shrew Sorex palustris Size small, total length approximately 91 mm or less, hind foot tiny, never fringed, third unicuspate tooth a minute and inconspicuous disk squeezed between adjoining teeth, anterior teeth (bicusps) spaced apart with expanded medial tines .................................... Pygmy Shrew Sorex (Microsorex) hoyi


85

5

5’

Size small, total length 102 mm or less, length of skull less than 16.5 mm, unicuspate teeth even except diminutive peg-like fifth, rostrum exceptionally slender, cranium slightly arched ................ .... Masked Shrew or Cinereous Shrew Sorex cinereus Size medium, total length greater than 102 (106-121) mm in adults, length of skull exceeds 16.5 mm, unicuspate teeth large, rostrum wide, cranium prominently arched, tricolored pelage (black dorsally, brown, pale brown) in winter pelage .... ...................................... Arctic Shrew Sorex arcticus

Genus Sorex Linnaeus Long-tailed Shrews There are five unicuspate antemolar teeth and the tail is relatively long. Mammae: 6.

Sorex cinereus Kerr Masked or Cinereous Shrew 1792. Sorex arcticus cinereus Kerr. Animal Kingdom, p. 206. Type from Fort Severn, Ontario, Canada 1842. Amphisorex lesuerii Duvernoy. Mag. Zool. d’Anat. Comp. et Paleontol., 1842. 25:33. Type from Wabash Valley, Indiana. 1827. Sorex personatus I. Geoffroy St.-Hilaire. Mem. Mus. Nat. Hist. Paris, 15:122. Type from eastern United States. 1942. Sorex cinereus lesuerii: Bole and Moulthrop. Sci. Publ. Cleveland Mus. Nat. Hist., 5:95. See also Jackson 1961, for southern Wisconsin. 1925. Sorex cinereus cinereus: Jackson. J. Mamm., 6:56.

Sorex cinereus cinereus Kerr The name Sorex by Linnaeus means shrews, and cinereus means gray. The name Cinereous Shrew used by Jackson (1961) and others

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Skull of Sorex cinereus.

is not entirely appropriate, for the shrew is brownish gray, but it is far more appropriate than “masked” shrew because there is no mask. Besides, Jackson’s classic work on shrews may allow him to set precedence on names for shrews, based on his extensive work on them. Furthermore, the animals called masked shrews recently have been divided into several species. Description. This tiny mammal is one of the smallest mammals in Wisconsin, perhaps a little larger than Wisconsin shrews of the species Sorex (Microsorex) hoyi. The masked shrew has a slender snout, and the rostrum of the skull is correspondingly slender. The tail is relatively long. The bicuspate teeth are hardly separated by expanded tines, therefore nearly adjoined in front, and the four anterior unicuspate teeth on each side are small and evenly aligned (the fifth is peg-like and diminutive). There is no post-mandibular canal in the dentary. The pelage of the masked shrew is brownish gray or dark brown, with paler underparts (grayish white, smoky gray, or buffy white). The feet are brown, and the bicolored tail dark brown above, paler below; in winter, the upper parts are more grayish. Molts April through June, and winter fur is acquired in October (Jackson 1961). The sexes seem similar in size. Some representative external measurements for adults from Outer Island of the Apostle Islands, Brick Creek, Clark Co., and six young from Portage County (with cranial measurements as well) are respectively as follows: 94.0 ± 11, 105.9 ± 4.6, 95.5 ± 3.8; 38.14 ± 1.6, 39.4 ± 2.6, 38.2 ± 3.7; 10.3 ± 1.0,

12.8 ± 1.1, 10.8; wts. 4.63 ± 1.1 g, —, —, N = 6: greatest length of skull 16.7 ± 0.3, cranial breadth 7.48 ± 0.2; interorbital breadth 2.69 ± 0.11 mm. Twenty specimens of various ages from Portage County averaged 16.4 ± 0.2 (16.1-17.1), 7.5 ± 0.2 (7.1-7.8), and 2.7 ± 0.18 (2.5-3.2) mm. Dental Formula. The teeth of the masked shrew number 32; five unicuspate teeth are present. The formula is I 1/1, U 5/2, P 4 1/0, M 3/3. (I = incisor; U = unicusp or “unicuspid”). Geographic Distribution. Jackson (1961) had no specimens from any of the southwestem counties, suggesting this species did not

Maps showing geographic distribution of Sorex cinereus in Wisconsin and North America.


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occur in these prairie counties. The species has been obtained from most of them, and appears to range throughout the state. Status. The masked shrew is abundant throughout most of the state, and decidedly beneficial in controlling insects. The masked shrew is important in many food chains (see Mortality below), and it preys on injurious insect pests of crops and spruce trees. Habitats. This boreal species ranges southward and westward into the prairies, and is often taken in dense, wet prairies. Usually it inhabits wet forests, swamps, bogs, and marshes. It occurs in many habitats (Getz, 1961d, Long 1974), including some sandy, grassy and forested. The nest of the masked shrew is composed of leaves and grasses, located near the surface of the ground in a cavity, under a log, stump, or rock. The shape about three inches in diameter, with the inner nest scarcely more than one-half inch in diameter. There seems to be a single entrance (Jackson 1961). Foods. A variety of insects, insect larvae, worms, spiders, flesh of mice and other shrews, seeds, and other vegetal material comprise the foods of the masked shrew. Frequencies are insects (65.3%), small vertebrates (7.1), centipedes (6.8), worms (4.3), mollusks (1.4), sowbugs (1.2), vegetal (0.9), Arachnida (0.9), and undetermined (10.9) (Hamilton 1920). The mammals eaten may in some cases be carrion. Whitaker and Mumford (1972) examined stomachs of 50 masked shrews in Indiana finding 26 kinds of foods, mostly larval moths, butterflies, crickets, beetles (adults and grubs), and leaf hoppers. Reproduction. Young-of-the-year masked shrews do not normally breed. Their second year is perhaps the only opportunity. Breeding commences in March and lasts into October. Usually one, but as many as three litters a year, is produced. Males exhibit narrow dorsolateral “flank” scent glands during breeding. They also occur on the flanks of females but are much smaller. There are six mammae. Six pregnant females from central and northern Wisconsin, and one from Upper Michigan, averaged 5.3 (2-9) litter size. They were preg-

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nant on dates from April 24 to October 24. Two lactating females were seen on October 8 and October 18. The young are born pink, naked and blind, after a gestation period of about 18 days. They are about 13 mm long and weigh 0.1-0.3 g (Blossom 1932, Kilham 1951). After 12 days, young weigh as much as 2.8 g each and are haired out. The erupted teeth are not yet visible. Teeth begin to erupt between 9 and 14 days. After 19 days young are weaned and ready to follow the parents about. Buckner (1970) observed parents feeding numerous fritillary butterflies to their young, gathered together in the shade of a log. The butterflies had been sucking water from wet sand. Shrews do not live long in nature, and the populations may be practically categorized as two age groups. These have been classed as I and II, or young and old adults. The youngof-the-year usually have longer skulls, with the braincase more arched. Their teeth are usually less worn. The cingulum or circular ridge around the base of the crown portion of the bicusp in young animals “is oppressed to the dentary” (sic, i.e., the premaxillary, Hoffmeister 1989; Diersing 1980). With increasing age and growth the exposed root increases in length and pushes the cingulum away from the alveolus. The distance seems directly correlated with age, at least in comparing one specimen with another from the same place. Mortality. Sometimes carnivores refuse to eat masked shrews owing to their odor, which probably results from the rectal glands. Weasels, skunks, foxes, badgers, wolves, and bobcats all kill shrews (Murie 1936). Occasionally large frogs catch and eat these tiny shrews, as do snakes and birds of prey (Gould et al. 1964). Even a brown trout caught one in Schoolcraft County, Michigan (Baker 1983). A variety of fleas and ticks infest these shrews (Jackson 1961, Timm 1975). A comprehensive list of parasites was published by Whitaker (1974). Home Range and Density. Jackson (1961) says the home range of the masked shrew does not exceed one-fourth acre (or 1200 square yards). Ozoga and Verme (1968) found Sep-

tember populations contained 40 percent young-of-the-year. In Marquette County (Upper Michigan), Manville (1949) found four shrews per acre (10/ha) in northern cedar swamp, and three per acre (7.5/ha) in black spruce. In Baranga and Marquette counties, Haveman (1973) found 11 per acre (27.5/ha) in spruce swamp, nine per acre (22.5/ha) in bogs, and four per acre (10/ha) in spruce barrens. Anderson (1977) found 93 per acre (240/ha) in hardwoods. Deep frost kills small mammals, both shrews and their prey, and the cessation of reproduction prohibits replacement of shrew populations suffering mortality. Density in shrew populations falls throughout the winter. Remark. Long and Affeldt-Gehring (1995) reported a partially albinistic masked shrew showing the Valais goat color pattern. This pattern of pigmentation of the fur in which the anterior half of the animal is normally pigmented, and the posterior is white, has been reported as developmentally possible in only medium-sized mammals, such as goats. This single record of the Valais pattern in such a tiny mammal may falsify the mathematical rule of Valais color pattern pigmentation and size-dependence (Murray, 1989). Patterns that show bicolored patterns white at each end also were never to be found (but see the Blarina account beyond). To make a long mathematical story short, little mammals, such as shrews, were thought to develop too fast for such a constrained pattern of pigmentation to develop. Additional Natural History. Significant works on masked shrews and other shrews are written by H.H.T. Jackson (1928), Junge and Hoffmann (1981), and Findley and Yates (1991). Geographic variation. There is a single geographic race in Wisconsin. Jackson (1961) referred shrews from southeastern Wisconsin to S. c. lesuerii (Duvernoy), but Hoffmeister (1989) determined its boundary was much farther southward, in Illinois. S. haydeni, which some regard as a distinct species, reportedly occurs together with S. c. cinereus in Iowa and Minnesota.

Specimens examined. Total, 530. Adams, Ashland, Bayfield, Burnett, Calumet, Clark, Columbia, Dane, Door (Rock Island, 1. Pedants Road, north end Washington Island on Lake Michigan, 2. Swenson Road, 1/2 mi. E Jesson’s Place, 3. Jessens Place on Swenson Road 2. Washington Island, 1. Detroit Island, 2. Bailey’s Harbor, 1), Douglas, Florence, Forest, Green, Grant, Iowa, Jackson, Jefferson, Juneau, Kewaunee, Langlade, Lincoln, Manitowoc, Marathon, Marinette, Milwaukee, Monroe, Oconto, Oneida, Ozaukee, Pepin, Portage, Price, Racine, Rock, Rusk, Sawyer, Sauk, St. Croix, Taylor, Trempealeau, Vilas, Washburn, Washington, Waupaca, Wood counties. Other records.— Ashland Co. Apostle Islands including Madeline, Oak, Outer, Raspberry, Rocky, Sand, Stockton and York isles (Kantak, 1981).

Sorex arcticus Kerr Arctic Shrew 1792. Sorex arcticus Kerr. The animal kingdom. p. 206. Type from Fort Severn, Hudson Bay 1837. Sorex richardsonii Bachman. J. Acad. Nat. Sci. Philadelphia. This name also used by Lapham (1853), Strong (1883), Snyder (1902), Hollister (1910), Jackson (1908), and Cory (1912). Type from Saskatchewan. 1858. Sorex pachyurus Baird. Mammals. In Reports Explor. Survey... Pacific Railway Route, 8(l):20. Type from Pembina, North Dakota. A homonym of Sorex Pachyurus Kuster, 1835, from Sardinia.

Sorex arcticus laricorum Jackson 1952. Sorex arcticus laricorum Jackson. Proc. Biol. Soc. Washington, 38:127. Type from Elk River, Minnesota.

The scientific name literally means arctic shrew. The adjectives “tricolored” or “sadTAXONOMIC ACCOUNTS / ORDER INSECTIVORA

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dle-backed” shrew were descriptive names applied in the past. Never in the original description, his revision of the long-tailed shrews or his book on Wisconsin mammals did Jackson ever discuss the meaning of his word laricorum. The Latinized name may be loosely translated as “a denizen of larches” (American tamaracks). This is a fine epithet, for tamarack marshes are a preferred habitat. Description. Arctic shrews are mediumsized, with long snout and long bicolored tail. The body and skull are larger than those in Sorex cinereus (see Measurements). Pelage in summer, and in young-of-the-year, is brown dorsally, slightly paler below; in adults there is a black mid-dorsal longitudinal band extending from nape to base of tail, and the belly is grayish brown. This pattern is tricolored: black, brown, and paler grayish brown. Three specimens in molt were taken from late September to late October. The cranium is arched, never flattened, the unicuspate teeth brightly pigmented on the tips of unworn cusps, the third unicusp tooth is larger than the fourth, the fifth a minute peg. The skull of the water shrew has the third unicusp smaller. The rostrum, though narrow anteriorly, is broader across the cheek teeth. A post-mandibular canal is found in the dentary in S. arcticus. Arctic shrews have trivalent sex chromosomes, X and two Y’s. Females are XX. The

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Skull of Sorex arcticus. THE WILD MAMMALS OF WISCONSIN

diploid number is 29 in males and 28 in females (Kirkland and Schmidt, 1996). Standard external and some cranial measurements are included here from several localities in northern Wisconsin (Drummond, one Ad, F. and Medford 4 Yg and Ad M), respectively: Total length, 116; 114.25 (106119), tail 45; 42.0 (39-45), hind foot 14; 14.5 (12-17), weights 7.0 g; 8.8 (7.8-10) g; greatest length of skull 21.1; 19.8 (19.6-19.9); cranial breadth 9.54; 9.1 ( 9.08-9.11); and breadth across the maxillary processes 7.0; 5.01 (4.93-5.09). From Portage County, 16 Yg and Ad males measured 111.7 ± 0.74, 40.5 ± 5.3, 13.5 ± 1.2,and N = 5 M, age class 2: 19.6, 9.47, and 5.05, respectively. Other measurements are listed in Kirkland and Schmidt (1996) and in Clough (1963). Dental Formula. The dental formula for Arctic shrews is the same as in Sorex cinereus, but teeth are larger. I 1/1, U 5/2, P4 1/0, M 3/3 = 32. Geographic Range. Common in Upper Michigan, but restricted from the Lower Peninsula by Lake Michigan, the Arctic shrew ranges throughout most of the northern counties of Wisconsin, and occurs in southern Dane and Dodge counties (Clough 1960; Lowell Getz, personal communication). Status. The Arctic shrew is seldom common, but lives in remote marshes and wet prairies so that it maintains fair abundance, except where these are drained or polluted. It has little economical importance, except that it feeds on larch sawflies and other forest insect pests. Habitat. Arctic shrews dwell in marshes, the grassy edge of cedar, spruce and tamarack swamps and bogs, stream valleys, and near some lakes. Whitaker and Pascal (1971) found them in old fields in Minnesota. This species seems limited to the boreal, coniferous forest region in North America, in the appropriate marshy and tamarack habitats. In central Wisconsin, I have taken them in dense grassy marsh, quite hummocky, but also where the black soil is level and evident through the grasses. Cedar, alder, tamarack,

and a few spruce were at the edge of the marsh. Clough (1963) also caught them in hummocky marshes. Schmidt (1931) caught one in a sphagnum bog. Little information is available on homes of Arctic shrews. Reportedly the nests are globular “surface” structures comprised of grasses and other vegetation (Clough 1963, Baker 1983). Foods. Clark (1972) found some arthropods in several stomachs of Arctic shrews. Arctic shrews are often snap-trapped with rolled oats and peanut butter. In 62 specimens from Manitoba, the diet was exclusively

Maps showing geographic distribution of Sorex arcticus in Wisconsin and North America.


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Arctic shrew. P. Kim Van. 1995.

insects (Buckner, 1964), especially noteworthy the pest larch sawfly. A captive from Stevens Point fed regularly on mouse carcasses, never feeding on dead songbirds. Reproduction. Clough (1963), Baird et al. (1983), and Baker (1983) reported litters as large as ten, averaging seven. Birth occurs in April and May, and occasionally later. Jackson (1961) suggested that September breeding indicated that a female might have two litters each summer. Buckner (1966) found a few female youngof-the-year may breed. This suggests a typical pattern of small mammal breeding in Wisconsin. Arctic shrews have winter carry-overs, which reproduce and may die, and young of the year reproducing later in summer. Nora Lopez-Rivera found an entry in the Hamerstrom’s field journals of a pregnant Sorex arcticus taken 30 April 1979 in the Buena Vista Marsh. It contained 7 embryos. I collected a lactating female 1 mi. E. Jordan Pond on 5 August 1968, and Carl Becker caught one 30 October in winter pelage with teats barely visible. Embryo counts range from 4-9 in central Wisconsin ( mean 6.6, N=10). In Minnesota, near Minneapolis, 113 female Arctic shrews showed evidence of breeding from April (lactation) into September (observed lactation). Reproduction ceased by October. Males were reproductively active from April to August. Young entered the population in June. Most did not breed the first year. Litter size in Minnesota was 7.7+ 0.42 SE, range 5-9 (N=10). Mortality. Nelson (1934) found the remains of an Arctic shrew in a great-horned owl pellet. One dead Arctic shrew observed in central Wisconsin was dropped by a coyote

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on snow. A long-tailed weasel killed one. There are various parasites such as fleas, mites, and ticks reported by Timm (1975), Kirkland and Schmidt (1986), and Whitaker and Pascal (1971). This shrew lives up to 18 months. Home Range and Density. There is no information on home range in Wisconsin Arctic shrews. They may occur in densities as high as five per acre (12.5/ha) (Banfield l974). Clough (1963) estimated densities as 3.5 per acre (8.8/ha). Haveman (1973) found densities to be four per acre (10/ha). Bucker (1966) reported home range based on 79 shrews to be 1.46 acres plus or minus 0.14 acres (0.6 ha). Kent (1983) found in his studies in Clark County, Wisconsin, that Sorex arcticus occurred in Northern Hardwoods and Northern Sedge Meadow. He only trapped approximately 6 specimens in 1979-1980. Although Sorex cinereus and Sorex (Microsorex) hoyi were much more abundant, Arctic shrews were taken along drift fences at the rate of 0.01 (N=3) and 0.02 (N = 3) per day in these two communities. Whereas Kent found S. arcticus rare in these communities, Sasse (1978) found it the most abundant of any of the six shrews present in this same study area, except rare in the Hardwood Forest. In 1976 (6-17 August), Sasse (1978) caught up to 22 specimens per night in Marsh and Shrub communities. The Arctic shrew was the most abundant mammal trapped in Shrub and Marsh communities, exceeding even the prolific meadow vole. I found Arctic shrews abundant in the Jordan Marsh, Portage County, co-existing with Sorex cinereus. Remark. Clough (1963) observed that captive Arctic shrews were docile, never bit, and in nature they are active either night or day. Geographic variation. There is no geographic variation evident in Wisconsin and Upper Michigan. The shrews exhibit constancy in cranial and external characters over a wide range. Specimens examined. Total, 151. Bayfield, Burnett, Calumet, Clark, Juneau, Langlade, Lincoln, Marinette, Marathon,

Portage, Price, Sheboygan, Taylor, Waushara, Wood counties. Other records. Hamerstroms’ Journals, Portage Co.: Buena Vista marsh. Clough, 1963. Jackson, 1961.

Sorex palustris Richardson* Water Shrew “Every individual of this species [Sorex palustris] was either in or at the edge of the water. In the water they swam beneath the surface; encountering obstructions... they crawled up and over these.... one was seen June 30, 1924, making its way up a small stream... it traveled on the ground, but it took to the water where the bank became too steep. Within a few minutes another individual came along, following the path of the first.... Along Manzanita Creek, June 6, 1926, a female was trapped at the opening of a small tunnel at the edge of the stream. This tunnel except for its smaller size appeared like the ordinary surface tunnel of a mole. Active individuals were observed at various times of the day, and on at least five occasions; twice animals swimming after dark were seen by aid of light reflected from a camp fire.... the animals appeared silvery, due to the air [bubbles] contained in their fur .” — Joseph Grinnell, Joseph Dixon, and J. Linsdale. In Vertebrate Natural History of a Section of northern California through the Lassen Peak Region. Univ. California Publs., Berkeley.

Sorex palustris hydrobadistes Jackson 1926. Sorex palustris hydrobadistes Jackson. J. Mamm., 7:57. Type from Withee, Clark Co., Wisconsin.

The name Sorex palustris means marsh shrew. Very seldom does this shrew range away more than 2 m from a stream, lake or *

The nominate race’s type was from “marshes” [of Canada].

standing water in a marsh, hence its vernacular name “Water Shrew.” Description. The water shrew is large for its family, largest of the Sorex in Wisconsin (see Table Ins-3), with a long tail, long pointed nose, hind foot broad and fringed with stiff hairs as an adaptation to swimming. The cranium is large, broad and flattened; rostrum narrow but abruptly becoming broader spanning across P 4/ to P4/ or M 1/1. The third unicusp is smaller than fourth. The pelage, especially of the dorsum, of the water shrew is slate gray to black, and usually blackish. Underparts of head, body and tail silvery gray to brownish gray. There is an iridescent purplish sheen on the dorsum in bright light (Baker 1983). Molt is observed on specimens in July-late August and early January-March, suggesting two molts per year (Jackson, 1928). External measurements of seven Sorex palustris adults from Seney Nat. Wildlife Refuge, Upper Michigan, and USNM specimens from St. Germain, Vilas Co., 1; Basswood L., Iron River, 1. Danbury, 2. Mercer, 1. Total length, 148.3 ± 5.2 (142-156), length of tail, 65.7 ± 3.6 (62-73); 19.25 ± 0.89 (18-20). The sample size was N = 9. One adult weighed 10.3 g. From several localities in northern Wisconsin, 3 adult males and 7 adult females averaged, respectively, as follows: 152, 150 ± 5; 76, 67 ± 1.4; 21.7, 18.57 ± 0.8; —, 11.91 ± 0.95 g, and five adult females aaveraged in cranial measurements 21.42 ± 0.39; 10.2 ± 0.46; and 5.9 ± 0.21 mm. Dental Formula. The dental formula is the same in Sorex palustris as in Sorex cinereus. DF = I 1/1, U 5/2, P4 1/0, M 3/3 = 32. Geographic range. Occurs throughout the Upper Peninsula of Michigan ranging southward in Wisconsin as far as Portage County. Status. An interesting and poorly known boreal species, the water shrew is chiefly insectivorous and, if not beneficial, certainly harmless to humankind. In Portage County the shrew has seemingly disappeared from some former habitats (e.g., Hay Meadow Creek), I TAXONOMIC ACCOUNTS / ORDER INSECTIVORA

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Skull of Sorex palustris.

suspect from the effects of insecticides. Possibly the use of toxins, including fish management poisons, may adversely affect these semiaquatic forms. Seldom abundant in any place, the small numbers in museums suggest rarity. Jackson (1961) observed only 10 specimens in all the collections he studied. Our collection contains only 22 Wisconsin specimens. Lacking evidence to the contrary, the species may be regarded as in peril. Management of streams and wetlands, therefore, should include this species for protection. Habitat. The water shrew dwells at the edge of streams, bogs, lakes, rivers, and standing water in marshes and swamps. It favors rocky, log-strewn cold-water streams, with numerous crevices and overhanging banks, and bordered by boreal woodlands (Borell and Ellis 1934, Conaway 1952). This animal forages on the banks, swims in the water, walks on the bottom, and runs across the water tension of still water (aided by light weight, large feet and bubbles in the fur). Jackson (1961) reports four water shrews from sphagnum and swamp laurel (Kalmia glauca) accessible to water near Rhinelander. In western Montana, from the distant race S. p. navigator, Conaway (1952) made a fine study on this poorly known species. The habitats he observed were always near cold-water streams with rapid currents, running through boulders, crevices, and stony areas. The vegetation along the water included liverworts, mosses, green and sidebell Pa-

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rola, baneberry Actaea rubra, bearberry Arctosphylos, and water cress Rorippa. The nearby forest was fir. In Canada I have taken the water shrew from the stony beach of the rushing outlet of a lake, with only a few grasses growing there, and in central Wisconsin from the black muddy sand along shallow creeks in marshy and swampy places, where the grasses and jewelweed were dense and tall. Little information is available on the burrows of water shrews. One nest was found in a beaver lodge (Seigler, 1956). The nest is about four inches in diameter, made of twigs and leaves. Bankside burrows are used for security, probably as homes (see quote preceding this account). Foods. The water shrew feeds chiefly on invertebrates, aquatic insects, water spiders, snails, small fishes, and on occasion vegetal material (Hamilton 1930, Whitaker and Schmeltz 1973, Buckner and Ray 1968, T. Clark, personal comm.). Buckner and Ray (1968) found carabid beetles the chief prey, with larvae of Lepidoptera and Hymenoptera, snails and other insects. In Montana, Conaway mentions insects in 49 per cent of the stomachs examined, and the chief foods were insects, a few planarians, and a little vegetation. Three shrews had fishes, either scales in the stomach or remains in the mouth. His captive water shrews also caught tiny fish. Occasionally he found mouse hair in a stomach, one contained hair of a nearby eviscerated water shrew. Reproduction. Very little information is known for water shrews in Wisconsin. The breeding season extends usually from January through August. Jackson (1961) suggests the gestation period is 21 days. Several litters, usually of six offspring (3-8) may be produced in a season. Young appear in the population by July, and probably breed their second year. The life span may not extend beyond 18 months (Conaway 1952). A specimen taken near Stone Lake, in Sawyer County, had 3 embryos measuring 5 mm in crown-rump length on 9 April 1969. Spiegler (1956) found four immature

water shrews in a water shrew’s home in the sticks of a beaver lodge (May 1954). They weighed 6.0-6.9 g (mean 6.4), and measured 72-75 mm in length (tail 24-27 mm). Conaway (1952) reported and reviewed reproductive records of water shrews, finding that in Montana the males begin spermatogenesis in January and February. Females show ovulation and lactation in March and as late as August. Three young females were breeding in June, and one was pregnant. No young males were observed to be sexually active. Old males were usually show-

Maps showing geographic distribution of Sorex palustris in Wisconsin and North America.


95

ing sperm development, or at least some stages of gametogenesis, after the winter. In Montana the streams were usually open in winter, and the shrews were active under ice shelves, but seldom on the snow. Being active, perhaps reproduction was not impeded much by winter. In any case, some embryos appeared in February. Altogether, Conaway’s records of litter size ranged from 5 to 8, with a mode of 6, and one female showed the transfer of blastocysts to the opposite uterine horn (5: 1 to 3: 3). Conaway (1952) found only two age classes in water shrews. His age classes were based on toothwear studies, and related to reproductive maturity. Mortality. Jackson (1961) listed predators that occasionally kill water shrews as weasels, garter snakes, and possibly hawks, owls, mink and large fishes, including trout (Doutt et al., 1966). Fleas, ticks, and mites are reported by Timm (1975) and Whitaker and Schmeltz (1973). Conaway (1952) found two fleas, Neactopsylla and Corrodopsylla, two mites Hirstionyssus and Euphagamogamasus, 4 species of nematodes including Capillaria, and two tapeworms Hymenolepis and Tetrahyridium. Home range and Density. Little information is available for Wisconsin water shrews. Buckner and Ray (1968) retrapped a shrew in Ontario six times, from five traps, providing an estimate of home range as 0.8 acres. Another was captured four times, providing an estimate of 0.5 acres. The first was taken in August, the latter in September. Geographic Variation. None was observed in Wisconsin. Specimens examined. Total 27. Bayfield, Clark, Forest, Langlade, Lincoln Marinette, Portage, Sawyer, Taylor, Vilas counties. Jackson’s (1961) records were examined, and also were mapped for comparison of range then and now. Vilas Co.: Lake St. Germain 1. Bayfield Co: Barswood Lake, 1. Burnett Co.

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Subgenus Microsorex Pygmy Shrews The genus Microsorex was relegated to the genus Sorex and given subgeneric status by Diersing (1980). Some students (e.g., Junge and Hoffman 1981, and others) have followed him in this arrangement, and others (e.g., Hall 1981) have not. Long (1972a) mentioned the utility of the name, meaning in Latin “little shrew” or shrew-mouse (versus “shrew” or shrew mouse). That is rather appropriate for possibly the smallest terrestrial mammal on earth. Do the pygmy shrews belong to a separate genus or under the umbrella of Sorex spp? The answer is not straightforward. Diersing (1980) considered the Microsorex as one end of a transition, being an extreme both in diminutive third unicuspate teeth, and in hypertrophy of an inner “tine” or style along each upper incisor for about half its exposed length. The tines are often worn away in older shrews (e.g., UWSP5014). He might have added another specialization, on the two anteriormost unicusps, which is the serial development of tiny but distinct internal cuspules on the so-called “unicuspate” or “unicuspid” teeth, set off from the apices of these teeth where the ridge from the apex meets the cingulum. This trait is developed also in Blarina. This same evidence can be taken instead as evidence for generic status for these shrews,

Sorex (Microsorex) hoyi. Philip Wright. Courtesy of J. Paradiso & the Johns Hopkins Press.

for in these trenchant characters Microsorex is not intermediate (Table Ins-3). Some shrews with a diminutive third unicuspate tooth, such as Sorex palustris (in Otisorex) and Sorex merriami (in Sorex), essentially lack tines on the bicusps. Repenning (1967) and Guilday (1962) mention another character, reduced entoconid height relative to the hypoconid, distinguishing ancient fossils of pygmy shrews from Sorex. There is no hybridization between Sorex (Microsorex) hoyi and other Sorex, although opportunity exists, and indeed the two kinds have been separated since the mid-Pleistocene (Hibbard 1944). The crux perhaps is the importance of the peculiar third unicuspate tooth. Is it really the extreme form of a transition? Or are diminutive third unicuspate teeth in other soricine shrews a parallel in evolution? They retain pigmentation seen serially in the teeth, whereas in pigmy shrews the disk has no pigment, no inner loph, no function at all except, perhaps, as a spacer. In the evolution of crowded teeth and exceptionally tiny body form spacing seems adaptive, and the “tines” of the upper incisors serve the same use. The disk tooth seems functional, not vestigial, and is seldom lacking, except in an observed specimen (UW-SP 648). In this abnormal specimen the disk is lacking along with the adjacent tooth adjoining anteriorly, on one side only, and this anomaly may have resulted from an injury. Feldhamer and Stober (1993) also reported a missing tooth

Table Ins-3. Characters of Wisconsin shrews: Blarina, Sorex, and Sorex (Microsorex) hoyi.

Species

“Tines”

4th < 3rd Inner

Blarina S. arcticus S. cinereus S. palustris S. (M.) hoyi

None Small Small Minute Large

No* Yes Yes No No**

Cuspules Hypoconid high Large Small Medium Medium Medium-large

*U3/ is pigmented but approaching discoid form; **U3/ is an unpigmented disk.

Yes No No No Yes

possibly resulting from injury. The disk is a specialization, altered beyond the ancestral typical unicuspate tooth. In company with the other advancements, Microsorex seems differentiated from other Sorex. The homolog (or analog) in Blarina (see below) suggests the origin of discoid form.

Sorex (Microsorex) hoyi Baird Pygmy Shrew 1858. Sorex hoyi Baird. Mammals, in Reports Explor. Surv. for a Pacific Railway Route. Vol. 8(partl):32. For 1857. Type from Racine, Racine Co., Wisconsin. Also, Diersing (1980), Long (1999a). 1858. Sorex thompsoni Baird. Mammals, in reports Explor. Surv. for a Pacific Railway Route. 8(l):34. See Long (1972a). Type from Burlington, Vermont. 1925. Microsorex hoyi intervectus Jackson. Proc. Biol. Soc. Washington, 38:125. Type from Lakeland, Oconto Co., Wisconsin. 1901. [Microsorex] hoyi: Elliot. Field Columb. Mus. Publ. 4 Zool. Series, 2:377.

Sorex means shrew, and the name Microsorex means little shrew. Philemus R. Hoy was a well-known amateur scientist from Racine, who sent a specimen to Dr. Fullerton Baird, who subsequently named the species in Hoy’s honor. Concerning “pigmy” versus “pygmy,” Hall’s students, except in this case, always went with American usage instead of a British or Canadian spelling. Jackson (1961) and (1972) also followed that convention, pigmy over pygmy, but Hall himself used “pygmy,” and others followed suit. An appropriate French saying is, Je crois il va du blanc au noir, il est petit n’est ce pas? Description. Sorex (Microsorex) hoyii is a tiny shrew with long tail, a pointed but relatively broad snout, tiny eyes and feet, and five toes on each foot. It very closely resembles the masked shrew in size, form and color, but is slightly grayer dorsally, tail shorter, TAXONOMIC ACCOUNTS / ORDER INSECTIVORA

97

and muzzle or snout less slender. The skull is more flattened, especially in older shrews, with rostrum broader, cheek teeth with entoconid reduced, compared to the hypoconid (posterior margin of the molar). The most trenchant character is the third unicuspate tooth, which is minute and hardly visible, squeezed between adjoining teeth as a wedge or disk, somewhat tilted and unpigmented. Difficult to observe, even with a dissecting microscope, the disk is practically invisible to the naked eye. The tiny fifth unicuspate tooth is also small and practically hidden by the tooth posterior to it, so that it is often said that when one casually examines the unicusp row only three teeth can be seen. In Sorex cinereus four (all except the fifth) are visible and they are rather even in form. In the pygmy shrew, the first and second unicuspate teeth are even, and conspicuous, the third cannot be seen, the fourth is much smaller than the anterior two, and larger than the fifth. The patterns can be suggested by the following: cinereus ////o and in Microsorex ll.lo where “o” is the tiny fifth unicuspate tooth and the period is the disk. This pattern can be discerned with careful examination with the naked eye. Additionally the gap between the upper bicusps is filled, except in some old specimens, with inner extensions called ‘tines.’ These spacers are elongate, extending along and adjoined to each inner bicusp. The pygmy shrew is brown or brownish gray above with bicolored tail, underparts

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Skull of Sorex hoyi. THE WILD MAMMALS OF WISCONSIN

grayer, sometimes whitish or buffy, and often tinged about the throat with rusty brown. Molt occurs in late April-May and in OctoberNovember (Long 1974). Wisconsin pygmy shrews do not belong to the dwarf races of the subgenus Microsorex (Long 1972; Whitaker and Mumford 1972), but the Racine specimens were extremely small. One winter specimen, found by Dr. Robert Freckmann, in Stevens Point, may be the smallest adult, terrestrial mammal ever found. Weighing only 1.8 g, and having teeth extremely worn (indicating great age), the tiny specimen may have lost some weight by desiccation, although it was found frozen in ice. Measurements and weights are as follows for four adult males from Bayfield, four from Drummond, and one from Pray: Total length, 81.25 (80-84), 85.5 (84-88), 94; length of tail 29.5 (28-31), 29.8 (28-31), 31; hind foot 9.75 (9-10), 9.75 (9-10), 9; 5.4 g (N = 1), —, 2.9 g; greatest length 15.6, — , 15.4; interorbital breadth 2.8, —, 2.9; cranial breadth 6.55, —, 6.6 mm. Adults weight about 4-4.5 g, in Wisconsin, but from the same race Jackson (1928) reported 2.1 and 2.9 g, from Elk River, Minnesota. Dental Formula. I 1/1, U 5/2, P 4/ 1/ 0, M 3/3 = 32. The disk is a permanent tooth. Geographic Range. The pygmy shrew probably is restricted from hot, dry prairies in the west and south, where few specimens have been found. Specimens formerly referred to M. thompsoni (Long 1972a) were referred to S. hoyi hoyi (Diersing 1980), and in this I do not demur. Status. In many parts of the range of pygmy shrews the animals are spottily distributed, low in density, and over most of the vast range extremely rare. Some workers have taken them repeatedly with Sorex cinereus, but in the low ratios of say 50:1, or even 100:1. In southern Wisconsin the pygmy shrew is even rarer; only a few specimens have ever been caught. Their habitats are disturbed by man so much the species seems likely extirpated there. In central and northern Wis-

consin the shrew is uncommon but habitats for the species are being devastated by “urban sprawl”. Habitat. This boreal shrew inhabits most northern habitats (except the frozen tundra), occurring in a variety of climax forest and even seral habitats. Not found in dry prairies, it does occasionally occur in dry grassy areas, in tamarack, cedar, alder, and spruce swamps, with sedge grasses or sphagnum, in marshes, grassy meadows (dry, wet, even mowed), on stream banks, in coniferous and mixed coniferous forests, and even dry woodlands not too far from water. Beech-maple

Maps showing geographic distribution of Sorex hoyi in Wisconsin and North America.


99

forest, pine barrens, and sphagnum bogs are all inhabited on occasion by pygmy shrews. Usually the habitat is near a stream or standing water, and soils are patchily wet and dry (Long 1972c). The use of pitfall traps provided a precious number of modern-day specimens to be accumulated. In Manitoba, the pygmy shrew displayed a wide tolerance for diverse habitats, except tundra, arid grasslands, and cultivated fields. They were collected in fen, marsh, bog, and shrub thickets, also deciduous and coniferous forest and savanna (Wrigley et al., 1979). One was taken in “prairie.” No information is available on dens of the pygmy shrew. It is said to dwell in burrows, under a rock, or in roots of fallen trees. A captive shrew made several nests of cotton, open at both ends. Foods. Little information is available. Captive pygmy shrews have fed on flesh of mice, other shrews, earthworms, but more likely in the wild they feed on small insects and insect larvae. The tiny, southernmost race S. hoyi winnemana fed on insect larvae, spiders, beetles, and ants (63 stomachs) according to Whitaker and Cudmore (1988). Haveman (1973) found flies, beetles, other insects, spiders and a little sphagnum moss in the diet of our race, observed in Upper Michigan. Reproduction. In central Wisconsin pygmy shrews, there is no evidence of breeding more than once in the year. The only pregnant female was taken rather late (July), and most females were not pregnant at all. Dr. Philip Wright (personal correspondence) mentioned to me evidence that in Montana one female seemed to be in the process of producing a second litter while nursing an earlier one. Pregnant females carrying 2-7 embryos have been reported from 8 June to as late as 3 August (Jackson 1961, Long 1976, Scott 1939, and Osgood 1938). Hoffmeister (1989) mentioned a Manitoba specimen lactating in September. If breeding regularly commences in June and continues into September, more than one litter per year may be possible, but

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in Wisconsin that would seem infrequent. Possibly obscuring the problem, many females caught may be young-of-the-year, and too young to breed. Feldhamer et al. (1993) examined toothwear to age specimens of Sorex hoyi, considered comparable to shrews of known age of other species. The age was subtracted from the date of capture to estimate birth date. They found southern pygmy shrews breeding in all months of the year with a peak of breeding in late winter. Using their method (but excluding old shrews), I estimate in Wisconsin the pygmy shrews breed from June to September, occasionally later, with peak reproduction in July. Most females I examined were of youngof-the-year shrews. In lower Michigan, none of 18 young-of-the-year pygmy shrews (August 19-23) were sexually active (Baker, 1983). Mortality. House Cats catch pygmy shrews but seldom eat them because of the rank odors from anal and flank glands. Other predators include brook trout, garter snake, and hawks (Cahn 1937, Long 1974). Fleas, mites, a tick (Ixodes), and hymenolepidid tapeworms parasitize pygmy shrews (Buckner and Blasko 1969, Long 1974). Home Range and Density. Long (1974) caught four pygmy shrews in about half an acre in central Wisconsin over a period of several weeks. The collecting was terminated on behalf of the rare shrews. Wrigley et al. (1979) studied the habitats and abundance of Sorex hoyi in Manitoba. The shrew was most abundant in aspen forest and black spruce forest, two taken from tree-line habitats. In central and northern Wisconsin the pygmy shrew is locally more abundant than that in some places, even outnumbering masked shrews. Geographic Variation. Jackson (1925) named pygmy shrews from northern Wisconsin as Microsorex hoyi intervectus. He used the vernacular names “Northwestern Pigmy Shrew” and “Intermediate Pigmy Shrew.” Supposedly it had a broader and higher braincase than the nominate race hoyi. Baird’s

excellent illustrations (1858, for 1857) of his holotype for the nominate race reveal that the description of the nominate race was misconstrued; it agrees closely with that of shrews from northern Wisconsin. I (1972a) placed intervectus in the synonymy of Microsorex hoyi hoyi (= Sorex hoyi hoyi). Specimens examined. Total 49. Adams, Bayfield, Burnett, Clark, Jackson, Juneau, Manitowoc, Portage, Price, Sawyer, Winnebago counties.

The lower anteriormost antemolar tends to be only bicuspidate instead of tetracuspidate, and dorsally the red-brown labial walls are nearly straight.

Blarina brevicauda (Say) Northern Short-tailed Shrew 1823. Sorex brevicaudus Say. In Long. Account of an exped. Rocky Mts., 164. Type from near Blair, Nebraska. 1858. Blarina brevicauda: Baird. Mammals, in Re-

Genus Blarina Gray Short-tailed Shrews The dentition in Blarina resembles that of Sorex in many respects. Large size notwithstanding, the short-tailed shrews are rather typical shrews. The ear is a narrow slit hidden by fur of the head, and in this trait as well as having a relatively short tail Blarina resembles Cryptotis. Doubtless related to its size and strength, the skull of this semi-fossorial predator is robust, broad, with prominent ridges and sharp lateral processes on the braincase for muscle attachment. Such processes are not developed on the papery thin and smooth skulls of smaller shrews. The fifth unicuspate tooth in Blarina is tiny and hidden between the adjacent teeth on either side, but it is pigmented and pointed like the others. There is a crista extending from the apex to the inner cingulum. On the other unicuspate teeth inner pronounced cuspules are present. It is, therefore, slightly inacurrate to refer to these complex upper teeth as unicusps or unicuspids. The third unicusp is smaller than the fourth, extremely compressed as a sulcate disk, i.e., concave posteriorly to accommodate an anterior ridge protruding from the fourth. In this specialization and several others (Table Ins-3), for one the remarkable cuspules on the unicusps, there is some resemblance to Microsorex. The dentary is stout and deep to accommodate exceptionally large molars. There is a post-mandibular foramen.

ports Explor. Survey . Pacific Railway Route. 8(l):42.

The name Blarina, proposed by J. E. Gray in 1838, may refer to Blair, Nebraska, near the type locality. The specific part of the binomen literally means short tail. Because of its extensive burrowing and large size the mammal is often called the “mole shrew” or confused with moles. The burrows may descend half a meter below the soil surface in friable soil (George et al., 1986). Description. The trenchant characters for the short-tailed shrew are given for the genus above. Thorn-like lateral processes on the cranium, one on each side, and large size of the skull identify the skulls of Blarina from those of other shrews. Compared to other Blarina, the northern short-tailed shrew has a larger, stockier body, bigger feet, and a somewhat blunt or truncated nose. Blarina brevicauda has a karyotype of 2N=48 to 50 chromosomes

Skull of Blarina brevicauda.


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(George et al. 1986). Females have six mammae. In Wisconsin, B. b. brevicauda is typically larger and paler than B. b. kirtlandi. The color of Blarina is slate black or grayish black, often heavily suffused with dull brown. The undersides are similar but paler. Molt occurs at least once (in August and July) and is reported to occur in early winter (Jackson 1961). Northern short-tailed shrews are about four or five inches in length, and the tail is approximately an inch. Weights vary to 30 g. See Table Ins-4. (Cahn 1937, Long 1974). Dental Formula. I 1/1, U 5/2, P 1/0, M 3/3 = 32. Geographic Range. The Northern shorttailed shrew occurs throughout Wisconsin, doubtless in every county. The nominate race is restricted to the Mississippi and the St. Croix drainage basins and the Wisconsin River valley, excluding Dane County and localities southward. Status. The short-tailed shrew is decidedly beneficial to man. It also is important in

food chains of many predators (George et al. 1986, Baker 1983). The animal is common, but contrary to what is often said (e.g., see Jackson 1961), is not the most abundant Wisconsin mammal. Habitats. This ubiquitous shrew is found with varying densities in most terrestrial habitats of Wisconsin. It especially prefers woodlands with open floors, thick leaf litter or wellrotted humus, and an abundance of rotted logs and stumps. Not only in dry woods (e.g., the summit of Mosquito Hill near Green Bay), this species flourishes in wet, black soil of cedartamarack-spruce swamps. The nest is made of various plants, even hair. The tunnels extend either way from the nest and may be directed downward. One tunneled under our garage door and stole pieces of dog food from the nearby food pan, carrying the pieces one by one to a garden hose, then dashing to the burrow entrance. It would tug “mightily” and with surprising strength to pull food pieces from our fingers. Blarina caches foods in its burrow.

Table Ins-4. Populations of Blarina and Cryptotis. Cryptotis were from Wisconsin and Illinois. Total l.

Tail l.

Hind Foot l.

Greatest l. Skull

Zygomatic breadth

Br. Max. Processes

Cranial Depth

Blarina brevicauda kirtlandi from Portage Country Adult F N=17

115.3±9.7

22.5±2.6

14.44±0.81

23.67±0.48

12.56±0.31

7.93±0.24

6.59±0.25

Adult M N=10

108.4±7.25

19.63±4.7

10.56±2.07

23.57±0.58

12.28±0.35

7.89±0.28

6.52±0.18

Old Ad. F N=3

108 – 101

25 – 22

14 – 14

23.9 23.7 –

12.8 12.5 12.3

7.4 8.6 7.6

6.55 6.45 6.10

Adult F N=33

118.09±9.2

23.48±2.6

14.65±1.2

24.27±0.5

12.77±0.35

8.04±0.28

6.63±0.26

Old Ad. F

116 112-120

23.8 22-25

13.75 13.14

23.7 23.6-22.9

12.75 12.6-12.9

8.03 7.75-8.35

Blarina brevicauda brevicauda from West, Wis., Mississippi Valley

Cryptotis parva #6506 Sauk Co. F. Alc.

63

16

9.7

–

–

–

–

Illinois N=4

60-94

15-19

9-11

16.1

3.4

7.4

–

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One day we found it drowned in the dog’s water pan (Museum specimen no, 5946). Other nest descriptions for Blarina are provided by Shull (1907) and Hamilton (1929). Shull’s nests, ranging from 12-15 cm in diameter, were comprised of tree leaves, grasses, sedges, nettle, goldenrod, and other plants. Hamilton found nests under rotting logs. One nest was of elm leaves and another of maple leaves, 30 cm below the surface. It contained seven young. Foods. Blarina, especially the larger species, prey extensively on small mammals and even small snakes. The saliva is a powerful

Maps showing geographic distribution of Blarina brevicauda in Wisconsin and North America.


103

digestive fluid for insects, and toxic to mice and other small vertebrates (Martin 1981, Pearson 1942, Lawrence 1945, Jeuniaux 1961, and Thomasi 1978). The bite may be considered weakly venomous to humans. Jackson (1961) presents a fascinating account by President Theodore Roosevelt of a shorttailed shrew killing a pine vole and a garter snake. Hamilton (1930) described an attack on a meadow vole lasting 10 minutes. The diet is chiefly insects and other invertebrates (crickets, moths and caterpillars, beetles and grubs, spiders, millipedes and centipedes, sow bugs, snails, worms, and also seeds and other vegetal material (De Byle 1965, Eadie 1949, Hamilton 1930, Ingram 1942). Some insects, such as the larch sawfly, are forest pests. Reproduction. Two or three litters may be produced by a mother Blarina in one growing season (Timm 1975). Seldom does a shrew live over a few months. One lived in captivity 27 months (Baker 1983). Young-of-the-year may breed in the first year (as did Mus. No. 6062, June 15, 5 embryos), and after the long winter only 6 percent of carry-overs live to produce a second litter (Pearson, 1944). I have only two records of pregnancy (each 5 embs). Hoffmeister (1989) only had six records for the southern race (mean number of embryos 5, range 2-7). He suggested that students do not carefully look for embryos. Possibly the females stick close to their burrows when pregnant and are seldom caught. Nowak and Paradiso (1983) report the litter size as usually 5-7 but it may number as high as 10. After a gestation of 21 to 22 days, naked helpless young are born measuring 22 mm and weighing about 0.8 g. After 17 days the furred young move in and out of the nest. They are weaned at 25 days (Blus 1971). Mortality. Although an unpopular food for carnivores owing to odors from the anus and flank glands, the short-tailed shrews are important in the food chains of many predators, including weasels, badgers, foxes, fishers, striped skunks, bobcat and house cat,

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ring-billed gull, five kinds of owls, red-shouldered hawk, water snake, even fishes (brown trout, green sunfish, largemouth bass). The great horned owl is a very important predator feeding on this shrew in Wisconsin (Errington et al., 1940). Doubtless many shrews are killed in winter by deep and enduring frost and consequent food shortage. Spring floods may also take a toll. Fleas, mites, chiggers, and even beetles (Leptinus) are ectoparasites (Jameson 1950, Moore 1949, Timm 1975, Whitaker and Mumford 1972, Scharf and Stewart 1980, and Wrenn 1974). A comprehensive review of parasites is provided by George et al. (1986). Home Range and Density. Especially in thickets and woodlands, throughout Wisconsin, short-tailed shrew densities may be high, leading Burt (1946) and Jackson (1961) to assume the species is the most abundant small mammal in the Midwest. My studies suggest that the meadow voles (Microtus pennsylvanicus) is much more numerous in meadows, weedy and grassy prairies, and marshes, especially in northern counties; and the white-footed mouse (Peromyscus leucopus) is much more abundant in the sandy and shrubby habitats of southern, western and central Wisconsin. Blarina usually ranked second or third in relative abundance with these two species. Jackson and I have two independent tallies of museum specimens from Wisconsin: Blarina. Jackson 393, Long (herein), 376; Sorex cinereus 329, 398; Peromyscus leucopus 537, 1,029; and Microtus pennsylvanicus 567, 548. These ratios, accurate in April 1991, probably have not changed. A Museum Index (Numbers of specimens preserved) is skewed in favor of the less common because one does not prepare all the common specimens. Nevertheless, Blarina is abundant and widespread in Wisconsin. On the Upper Peninsula of Michigan, Manville (1949) found 0.3 to 3.0 short-tailed shrews per acre in May (0.75-75/ha), and 8.5-

11.6 per (21-29/ha) acre in June, in Marquette County. Haveman (1973) found 19 per acre (47/ha) in hardwoods, 7 per acre in spruce swamp, and 5 per acre in bogs. Getz (1961d) found moisture important for any high densities. Nowack (1991) reported the density to vary from 3 to 30 per ha. The home range was 0.2-0.8 ha. Remarks. Specimen No. 5171, from King, Waupaca Co., has a pelage basally light plumbeous gray; distally the hairs become even paler with a buffy, yet silvery-white suffusion. There are some darker undertones showing in the fur of this nickle-colored shrew. The feet and tail were pale grayish tan, and the tip of the nose was black. A specimen (Mus. No. 7816) taken 30 Sept 1994 in Stevens Point seems of the Himalayan (see above) color pattern, as described in Sorex cinereus (see Long and Affeldt-Gehring, 1995). The muzzle is gray all around and including the eye. On either side gray is expressed in small patches above the ear canals. All four feet are gray. The tail is gray and around the base is a grayish tone. The soles of the feet and the lips and nose were pink. Most of the body was pure white. Eight days later, Mr. Dominic Berna, who lives on the same (Stanley) Street, brought in another, so closely resembling the first that surely the two were siblings. The distance between the captures was less than a quarter mile. The first shrew was trapped in a kitchen, with one normal colored Blarina. The second was trapped in a tool shed. Short-tailed shrews do not seem to be cannibalistic on other living Blarina, at least the near neighbors, and often they are found living together. Males probably search females out by smelling anal and body odors. The male has a distinct flank gland (with unknown function) prominent in the breeding season. Agonistic threats are territorial displays, and pulsating calls of high frequency are emitted as the animal searches about (unfortunately for the shrews, it may be heard by owls). These regularly emitted calls may aid in orientation.

Blarina brevicauda brevicauda (Say) For synonomy of the nominate race, see Blarina brevicauda (Say) above.

Range. Western counties in the proximate Mississippi River drainage, and including the lower Wisconsin drainage. See Map. Measurements. See Table Ins-4. Jackson (1961) ascribed larger shrews from western counties to the nominate race, smaller shrews eastward to B. b. kirtlandi. He believed males were larger than females. Measurements are given in Table Ins-4. Specimens examined. Total, 81. Ashland, Barron, Bayfield, Buffalo Co.: Cochrane 1. Burnett, Clark, Douglas, Grant, Iowa, Jackson, Jefferson, La Crosse, Monroe, Price, Richland, Sawyer, St. Croix, Taylor, Trempeleau, Vernon, Washburn counties. Other records. Ashland Co.: Apostle Islands including Madeline, Oak and Stockton isles (Kantak, 1981).

Blarina brevicauda kirtlandi Bole and Moulthrop 1942. Blarina brevicauda kirtlandi Bole and Moulthrop. Sci. Publ. Cleveland Mus. Nat. Hist., 5:99. Type from Holden Arboretum, Kirtland Twsp, Lake Co. Ohio.

Range. Eastern counties outside the proximate Mississippi River drainage, but including part of the Wisconsin River drainage. See Map. Specimens examined. Total, 294. Adams, Ashland, Columbia, Dane, Dodge, Door, Fond du Lac, Forest, Iron, Juneau, Kenosha, Kewaunee, Langlade, Lincoln, Manitowoc, Marathon, Marinette, Marquette, Menominee, Milwaukee, Oconto, Oneida, Outagamie, Portage, Racine, Sheboygan, Vilas, Washington, Waukesha, Waupaca, Waushara, Winnebago, Wood counties. TAXONOMIC ACCOUNTS / ORDER INSECTIVORA

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Genus Cryptotis Pomel Least Shrews This diminutive prairie shrew is characterized chiefly by its small size and exceptionally short tail. The short row of unicuspate teeth has only four, the posteriormost being a tiny peglike tooth practically hidden from view. Superficially the antemolar teeth resemble those of Microsorex, because the tiny, disk-like tooth in the Microsorex is difficult to see. Both shrews show three of the teeth, and a posterior fourth is hidden, a small peg. The molars in Cryptotis have high crests in unworn teeth. On the upper unicusps there are prominent cuspules, as in Blarina and to some extent in Microsorex. All the other shrews in Wisconsin have 32 teeth, but Cryptotis has only 30. The ear is hidden in the fur of the head. The lower anteriormost tooth is well developed but never tetracuspidate to my knowledge. The outer rim is nearly straight-sided.

Cryptotis parva (Say) Least Shrew 1823. Sorex parvus Say. In Long, Account... Rocky Mts., 1: 163. Type from Missouri River, Washington Co.: Nebraska. 1842. Brachysorex harlani Duvernoy. Mag. de zool. de Anat. Comp. 25:40. Type from New Harmony, Indiana. 1858. B[larina]. eximius Baird. Mammals. Reports Expl. for a Pacific Railway Route. 8:52. Type from DeKalb Co., Illinois. 1912. Cryptotis parva: G. S. Miller, Jr. Bull. U.S.

whitish or grayish, and the tail bicolored (brown above, paler below). Geographic Range. The three known Wisconsin specimens of Cryptotis are from three southern counties. It should occur in marshes and weedy prairies farther southward. Status. The least shrew is possibly extirpated in Wisconsin. Always rare, no least shrews have been obtained in Wisconsin since 1944. This shrew should be reintroduced in the Wisconsin fauna, into preserved and restored prairies in southern and western Wisconsin. The species, although one of our rarest mammals, is decidedly beneficial to humankind. Habitat. The least shrew prefers grassy prairie or grassy and weedy old fields, broomsedge, briers, cultivated fields, grassy meadows, open woods and, rarely, orchards. Herbaceous ground cover may be more important than soil type (Whitaker 1974). Little information is available on homes for least shrews. Jackson (1961) reports from other studies that the nest is globular, about four or five inches in diameter, composed of dry grass or leaves. There are usually two openings into the nest, which is sited under a rock or log, and sometimes underground at a depth of four or five inches. From Texas, Broadbooks (1952) described a nest found under a sheet of corrugated iron, about 100 m from a cat-tail marsh. About 7 inches in diameter, and 2 inches high, the nest was comprised of old willow leaves. An opening from a short tun-

Nat. Mus., 79:24.

The name Cryptotis parva means a small animal having its ear hidden. Description. Same as given for the genus. From the only Wisconsin skin of Cryptotis available, preserved in alcohol, the color is brownish gray. Illinois shrews are similarly colored. Some least shrews to the southwest have a chestnut dorsum. The belly is

106


Skull of Cryptotis parva.

nel entered the nest from below and a runway connected to it from the side. There was a “toilet area” or latrine at the edge of the nest, where numerous small insects were feeding. This latrine was about 3 inches in diameter. If disturbed, the young, barely haired out, tried to hide in the tunnel or burrow into the leaves. Foods. Hoffmeister (1989) summarized foods in Illinois as lepidopterans, grasshoppers, crickets, chinch bugs, spiders, worms, and unidentified arthropods, and occasionally seeds and flower parts. Hamilton (1944) in

Maps showing geographic distribution of Cryptotis parva Wisconsin and North America.


107

Indiana reported insects, earthworms, mollusks, centipedes, and some vegetation in diets of least shrews from eastern states. Reproduction. In Illinois, young of Cryptotis parva are born in spring and fall, with the number of young varying from 4-7 (Hoffmeister, 1989). Whitaker (1974) reported embryo counts as 4.9 (2-7) and litter size as 4.5 (2-7). Gestatation is about three weeks, and the young are haired with opened eyes in two weeks. Newborn weight about a third of a gram (Whitaker 1974). They are “full grown” in a month. Conaway (1958) presents data on growth. Broadbooks (1952) quotes Hamilton, that the young are born blind and naked and grow 0.1 to 0.5 g per day for about 3 weeks. Broadbooks also found an adult male in attendance with the female at the nest. In captivity, the female ate her young. Captive-produced litters averaging 4.56 young (range 19), weaned in 18-19 days. These were sexually mature in about 50 days. Probably least shrews breed from March until November, although October young would find cold nights and frost adverse. They live about 8 months, but as long as 31 months. Mortality. A red fox killed but did not eat a Wisconsin least shrew (Hanson, 1945). Great horned owls ate the other two Wisconsin shrews, subsequently found in their owl pellets. Hawks, owls, snakes and other shrews are likely predators. A flea and several species of mites parasitize least shrews. Home range and Density. Hoffmeister and Mohr (1957) reported populations in Illinois as high as 10-15 per acre, but in some years none. Geographic Variation. There is a single subspecies known from Wisconsin, and central Illinois. Specimens examined. Total, 1. Columbia Co.: Sauk Prairie, 1. Other Records. Total, 2. Jackson (1961): Columbia Co.: E of Prairie du Sac, 1 mi. ESE Dam on Wisconsin River, 1. Dane Co.: Pine Bluff, 1 mi. N Klevenville, 1.

108


Order CHIROPTERA BATS “If bats are to remain [on earth].... we must initiate conservation measures.... certain needs are obvious. Some caves harboring important colonies should be protected from undue human disturbance. The trend away from the use of the dangerous residual pesticides must be continued. People who work with bats should try to minimize the disturbance.... Finally, more people should become aware of the many aspects of a bat’s life; such awareness should make people more interested in the protection of these fascinating animals.” — Wayne H. Davis, in Bats of America, by the late Roger W. Barbour and Wayne H. Davis, 1969.

The Order Chiroptera is comprised of the only mammals that fly. Known popularly as bats, these aerial mammals are the only ones with wings, which are modified forelimbs having elongated fingers and elastic webs between them. Distal claws disappeared from the fingers of the hand, except on the functional thumb [and on the index finger in some primitive, tropical bats called flying foxes]. Flight is gliding and thrusting the body through the air, with the capability to ele-

Skeleton of bat. G. Cuvier, Le Règne animal. Woodcut. 1817, 1829.

vate trajectory. Volant locomotion, seen in several other distantly related mammalian groups, such as flying squirrels, is simply gliding (“volant” actually means flying). Bats, probably descended from primitive insectivores. The molar teeth are formed similarly in W-shaped patterns. Ancient fossilized bats (Jepsen, 1966; Simmons and Geisler, 1998), Icaronycteris index, Archaeonycteris, Palaeochiropteryx, and Hasianycteris are considered insectivorous, some with insects in their stomachs, and they all had advanced wings. These wonderfully preserved fossils from the Eocene epoch give a few clues to the evolution of wings and flight. In addition to toe webbing, there is in bats a flight membrane on either side called a patagium. It is a double-layered membrane of skin extending laterally on each side out to the wrist, to the tip of the fifth digit, and to the ankle or hind foot. Such a lateral membrane has evolved repeatedly in arboreal mammals, probably serving to hide the revealing shadow when the body is flattened against a branch (Spurway 1955) or to break the fall as the animal leaps from a tree. A tail membrane, found only in one other group (Order Dermoptera) stretches between the hind limbs (the uropatigium). Usually in bats the tail vertebrae are comprehended in this membrane. Several characters indicate a gliding origin of flight: bats and gliding mammals are all nocturnal, they fall into flight, bat patagia resemble gliders, and bats’ hind limbs could never leap from the ground. The glider has a great deal of potential energy accumulated by climbing (Long et al. 2003). When bats pull their wings downward and forward, by means of several pairs of relatively large shoulder and chest muscles, the forward edge of the wing is canted downward. Then air is thrust mostly behind, and the hind limbs join in this pumping thrust. Lift is achieved. The wind helps raise the wings to the power stroke position. When bats glide, aerodynamic lift is obtained from pitching the wings against the airstream. The light body is

lifted, although drag greatly increases. As the angle of attack is inclined the bat stalls. If one wing is extended into the airstream while the other is held close to the body, the bat “flits” (Eisentraut 1936). Many echolocating bats hawk insects. They rely on echos from high-pitched calls to “see” in the dark with their ears (Griffin 1958, and others). There are two suborders of bats, the Megachiroptera, or flying foxes, in the Old World tropics and Australia, and the widespread, abundant, and diverse Microchiroptera. The Microchiroptera have specialized wings, in most cases tiny but functional eyes, and have evolved several different patterns of echolocation. Novacek (1985) reports that the oldest known bats (from the Eocene of Wyoming and Germany) possess cranial features suggesting an early function of echolocation. Possibly the orientation sense arose in cavernicolous bats. Other features include the upright rod in the ear (the tragus), the palatal notch separating the premaxillaries (and their incisors), the soft rod attached to the ankle helping to make the uropatagium taut (called the calcar), and the flattened chest.

Big Brown Bats on Ceiling of Twin Bluffs Cave. 1977.

TAXONOMIC ACCOUNTS / ORDER CHIROPTERA

109

Table Chi-1. Incidence of rabies in bats of Michigan* (1965-78) and Illinois (1965-82). Of all bats tested, 5.8 percent were rabid. MICHIGAN Tested Rabid &%

Species Myotis keenii M. lucifugus L. noctivagans E. fuscus L. borealis L. cinereus N. humeralis Totals

27 75 12 1,093 55 12 1 1,275

0 0 2 48 3 2 0 55

0 0 16 4 5 16 0 4

ILLINOIS Tested Rabid 0 43 4 90 355 378 134 0 1,000

0 4 15 34 20 0

*Figures slightly revised.

Rabies in Bats One of only a few human deaths attributed to rabies transmitted by the overt bite of a bat (species unknown) happened near Blue Mound, Wisconsin (Jackson 1961, Long 1976). A man with no screen on his window was bitten on the ear. He did not seek medical treatment used against rabies virus. He contracted the disease. About 30 years ago I read a report in the local paper by the Portage County Health Officer that all bats were found to harbor the rabies virus. What this really meant was that the bats he sent to the State Hygiene Laboratory in Madison all harbored the virus. After examining the reports, I suspected the number of bats he reported did not exceed four. In Wisconsin tabulations (see Table Intro-2), few bats test positive. In comparison, numbers of dogs, cats, and even cows (bitten by some rabid mammal most likely) that were not inoculated against rabies showed higher incidence (but no longer is this true since implementation of dog immunization). Striped skunks (Mephitis mephitis) showed a high, often epidemic incidence. Constantine et al. (1979) found only 0.025 percent of naturally occurring bats harboring the virus. Other studies have shown about one percent or less (Trimarchi and Debbie, 1977).

110


Owing to a national interest in Lasionycteris noctivagans, and its particular strain of rabies virus detected in humans, workers at the Wisconsin Rabies Laboratory must determine which bats are dangerous and which are not. For example, an elderly man attacked by a bat in Texas, with no visible bite marks, contracted rabies and died a couple months later (1997). He and three other Americans died from bat rabies that year, all attributed to a virus of the silver-haired bat, Lasionycteris noctivagans. Two cases are of great interest. A recent Wisconsin death (November 1, 2000) of a man near Reedsburg, associated with silver haired bats by the viral strain, but health authorities blamed bats from his apartment. Those likely would not be silver-haired bats. Silver-haired bats migrate out of Wisconsin southward in October, and do so in large numbers at this time (~ October 14). September 4, 2004, a recovering 15-year old patient, Jeanna Giese, relates catching a “small, black bat” [Lasionycteris is the only black bat in Wisconsin] in a Fond du Lac church. She treated a bite on her hand with peroxide, but developed advanced symptoms of rabies October 15, and was transferred from St. Agnes to Children’s Hospital on October 18. Dr. Rodney Willoughby, infectious diseases and pediatrics, and with the family’s support, attempted an untried treatment, using a drip treatment of the neural protective agent Ketamine, he was able to fine tune the effect of Ketamine with Benzodiazepine. After two days or so he added Ribavirin and even a flu drug Amantidine. The drugs and induced coma protected the Central Nervous System. The immune system fully responded, and the patient progressed steadily. After about 80 days she was returned home, and has progressed daily. Willoughby says enthusiastically that “She will go to college”. This is the premier triumph over rabies. I reiterate, “Don’t pick up sick or wild bats; tell your children to leave helpless bats alone. If one is bitten, take rabies shots.”

In Michigan, Baker (1983) and Kurta (1979) reported of 1,247 bats examined by the Michigan Department of Public Health only 65 (5 percent) had rabies, with only 3 to 11

positive bats in any years. In contrast, 28 percent of 384 skunks were rabid. Both 5% and 28% are overestimates, because any animals captured while sick are more likely to be tested. In nature the percentages would be lower. Trainer (1957) and Long (1976) called for a better study of the bats in Wisconsin. In 1991, I begain identifying bats with the State Laboratory of Hygiene (J. Powell). The UWSP collection was for four years a repository (Tables Chi-2-4) for non-rabid Wisconsin bats.

tional, Austin, Texas, provides a handbook for building and siting bat houses.

Family VESPERTILIONIDAE Gray Evening Bats “The Ordinary Bats (Vespertilio, Cuv. and Geof.) — Have no leaf or other distinctive mark on the muzzle, and the ears separated; four incisors above, of which the middle two ones are apart, and six below, sharpedged and somewhat notched: their tail is comprehended in the membrane.”— Baron Georges Cuvier,

Bats in Houses

in Le Règne Animal, 1817, 1846.

The Bat. It has no feathers, yet has wings, It’s quite

This large and cosmopolitan family contains all the Wisconsin species. See accompanying figures, the key to Wisconsin bats, and the table of characters of Wisconsin bats. Vespertilionid bats in temperate and boreal latitudes, such as those in Wisconsin, show a complex interrelation of microhabitats (microtemperatures), migration, lactation, and growth. Growth rates of young raised in maternity roosts vary with air temperature. In tree dwelling bats, in their cooler roosts, the young and mothers often save energy by entering torpor. Their growth rates seem low. Bats continue growing throughout pre-fledging, pre-migration, and migration until the next season of reproduction. Lasiurus do not seem to lose body mass by lactation and tend to produce twins [even 3-4 young] regularly. They may forage primarily to feed the young, which do fledge at an early (low) percentage of adult body mass (61 percent in Lasiurus cinereus, 55 percent in Eptesicus serotinus, which regularly has twins). The growth rates of the pre-fledged young are lower than those in vespertilionid bats with single young. In all Wisconsin species there are two pectoral mammae, except Lasiurus (with four). In Lasiurus, with such a slow growth rate even in a short growing season, by migration to warm regions, little or no hibernation, and feeding on available insects year round, there seems to be compensation in maintaining energy budgets (Koehler and Barclay, 2000).

inaudible when it sings, It zigzags through the evening air And never lands on ladies’ hair. — Ogden Nash.

In Britain, many people introduced them into their attics where the guano is considered insulation or collected for rich fertilizer. Most Wisconsin people eradicate bats, but especially in older houses, bats may be found in any season, especially in autumn. There is a myth that sprinkling moth crystals will drive bats away, or stringing up an extension light will keep them out. Bats usually leave a house at twilight emitting a few drops of urine. Telltale stains on the eaves may mark the entrances, and tin or aluminum must be used to cover the hole when the bats or their young are not present in the house. Small cracks may be caulked. The best way to remove bats is to put on leather gloves and grab them as they sleep. Sometimes it is practically an impossible task to rid a house of bats. Near the Trees for Tomorrow camp and nature center, in Lincoln County, is a man-made bat shelter that harbors many Myotis lucifugus, an interesting place where adults and children are taken to observe the evening flights. The house is sited about 30 feet high and houses. Many “bat roosts” for the backyard are sold today. Most of them seem ineffective. Bat Conservation Interna-

TAXONOMIC ACCOUNTS / ORDER CHIROPTERA

111

It is now possible to identify some bats by their echolocation calls. Ultrasonic bat detectors today (see advertisements in the Journal of Mammalogy) provide detailed information on species identification of flying bats, spatial and temporal bat activity, habitat use and prey selection, and even the physiological processing of echoes (Fenton, 1981; Miller and Andersen, 1984; Thomas and West, 1984; Thomas, Bell and Fenton, 1987; and others). This procedure promises in this century to provide a superb survey of free-ranging bats in Wisconsin and the Upper Peninsula, whereas previously we relied mostly on banding of cave species or by netting to study the diversity and seasonal population changes (see table Chi-5, & Fig.) on seasonal fluctuations and abunance). Bats have an undeserved bad reputation. For some inexplicable but deep emotional feeling, or possibly (some would say probably) it may be taught to people to some extent, there is an apprehension of bats that is often expressed by hatred and disgust. Bats normally do not attempt to get into a woman’s hair. Neither are they usually rabid. Bats are highly beneficial, limiting the populations of harmful insects during the “night shift” when most insectivorous birds are sleeping (E.R. Hall, personal communication; Barbour and Davis, 1969). Bats should be protected, i.e., managed. Some American bats are listed as Endangered Species because they are so scarce and are vulnerable to destruction (in their nursing colonies or hibernacula). Kurta and Teramino (1992) and others also showed the adverse effects of urbanization to bats in Detroit, decreasing their abundance, species diversity and possibly their reproduction success. In suburbs, with numerous shade trees and attics, some species may increase. Barbour and Davis (1969), Kunz (1988), and Nowak and Paradiso (1983) are important references on American Chiroptera.

112


Key To The Wisconsin Bats 1

1’

2 2’ 3

3’

4

4’

5

5’ 6

Tail not extending beyond tail membrane (uropatagium) or extending less than 4 mm beyond it ................................... 2 Tail extends distinctly beyond the uropatagium (known from northern Illinois, but unverified for Wisconsin, a possible wanderer) ......... Mexican free-tailed Bat Tadarida brasiliensis A single pair of upper incisors ........... 3 Two pairs of upper incisors ............... 5 Upper surface of uropatagium densely furred, the skin not visible, two pairs of upper premolars, one of which is a minute peg, usually a whitish spot visible on shoulder, dorsal pelage more or less hoary ............................................... 4 Upper surface of uropatagium nearly naked, skin visible and scantily haired proximally, one pair of upper premolars, shoulder spot lacking, dorsal pelage brown .............................. Evening bat Nycticeius humeralis Dorsal pelage maroon brown, washed with hoary whitish or buff, greatest length of skull exceeds 16 mm, forearm greater than 45 mm .................... Hoary bat Lasiurus cinereus Dorsal pelage brick red orange or yellowish orange, thinly washed with hoary buff, greatest length of skull less than 16 mm, forearm less than 45 mm ......... Red bat Lasiurus borealis Dorsal pelage dark brownish or blackish washed with buffy or silvery white ....... ................................. Silver-haired bat Lasionycteris noctivagans Dorsal pelage brownish, reddish or yellowish buff, never washed whitish ..... 6 Dorsal pelage yellowish, tan or pale reddish brown, one large and one minute pair of upper premolars (total of 34 teeth teeth), hairs conspicuously tricolored (brown/ cream/ gray), forearm usually less than 36 .......... Georgian pipistrelle Perimyotis subflavus

6’

7

7’

8

8’

9

Dorsal pelage brown, or yellowish, pale, or reddish brown (faded pelage); normally one large and two minute pairs of upper premolars (total of 38 teeth) or only one large pair (total of 32 teeth); hairs never tricolored; forearm more than 36 mm. ....................................................... 7 Skull more than 18 mm in greatest length, forearm more than 44 mm, premolars 1/2 (total of 32 teeth) .............. .................................... Big brown bat Eptesicus fuscus Skull less than 18 mm in greatest length, forearm less than 40 mm, premolars normally 3/3 (total of 38 teeth). .............. 8 Ear pinna broad and long (16 mm or more from notch), maxillary tooth row more than 5.5 mm, elastic fibers of uropatagium forming a pattern of wide, prominent chevrons numbering approximately 7 (611) ....................... Keen’s or Northern Myotis Myotis keenii Ear pinna narrow, more recurved, and shorter(usually less than 15 mm), maxillary tooth row less than 5.5 mm, elastic fibers of uropatagium forming narrow, indistinct chevrons numbering approximately 12 or more ........................... 9 Dorsal pelage with metallic, brassy or coppery brown glint, never with pinkish or purplish suffusion, calcar not keeled

Vespertilionid bat. W. A. Weber, with Karl Schmidt.

or slightly keeled, sparse hairs extend beyond toes ................... Little brown bat Myotis lucifugus Dorsal pelage dull brown, dorsal and ventral pelage tinged pinkish or purplish gray over brown, calcar distinctly keeled, sparse hairs usually do not extend beyond toes ..................... Indiana Myotis Myotis sodalis

9’

Bat To his adroit Creator ascribe no less the praise — Beneficient, believe me, his eccentricities. — Emily Dickinson, about 1876

General changes in abundance in Wisconsin’s bats seem profound. Old literature, including Jackson (1961), suggests the red bat was most abundant, the big brown bat uncommon, but the situation is now reversed. Myotis lucifugus, ranging through forests and

Chart of Characters of Wisconsin Bats. Diagnosis to make comparisons easy. Asterisk means unknown in Wisconsin. P = small premolars. Species P. subflavus M. lucifugus M. keenii M. sodalis M. leibii* N. humeralis L. borealis L. cinereus E. fuscus L. noctivagans Tadarida brasiliensis*

Length forearm

Length tragus

Calcar keeled

No. incisors

32-6 34-8 34-8 34-8 30-34 34-8 36-43 50-8 44-8 39-43 40-5

~½ ear

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