Mammals of North America Read online

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  Mammals of

  North America

  Second Edition

  ROLAND W. KAYS and DON E. WILSON

  Princeton University Press

  Princeton and Oxford

  ARTISTS’ CREDITS

  Sandra Doyle/Wildlife Art Ltd.: Plates 88-91, 99-112

  Nancy Halliday: Plates 2-9, 28-32

  Elizabeth McClelland: Plates 10-18, 33-49, 92-98

  Consie Powell: Plates 76-87

  Wendy Smith: Plates 50-55, 65-75

  Todd Zalewski: Plates 1, 19-27, 56-64

  Cover illustration: Elizabeth McClelland

  Scat illustrations: Diane Gibbons

  Track illustrations: Susan C. Morse and Jesse Guertin Copyright © 2009 by Princeton University Press

  Published by Princeton University Press

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  Library of Congress Cataloging-in-Publication Data Kays, Roland, 1971-

  Mammals of North America/Roland W. Kays and Don E. Wilson.—2nd ed.

  p. cm.—(Princeton field guides)

  Includes bibliographical references and index.

  ISBN 978-0-691-14278-4 (cloth : alk. paper)

  ISBN 978-0-691-14092-6 (pbk : alk. paper)

  1. Mammals—North America—Identification. I. Wilson, Don E. II. Title.

  QL715 .K38 2009

  599’.097—dc22 2009001417

  British Library Cataloging-in-Publication Data is available This book has been composed in Galliard (main text) and ITC Franklin Gothic (headings and tabular material) Printed on acid-free paper.

  press.nathist.edu

  Edited and designed by D & N Publishing, Baydon, Wiltshire, UK

  Printed in Italy by Eurografica SPA

  10 9 8 7 6 5 4 3 2 1

  Roland W. Kays is the Curator of Mammals at the New York State Museum. His research centers on the ecology and conservation of temperate and tropical mammals, especially carnivores.

  Don E. Wilson is Chairman of the Department of Vertebrate Zoology at the Smithsonian Institution’s National Museum of Natural History. Recipient of a Smithsonian Institution Award for Excellence in Tropical Biology and a U.S. Fish and Wildlife Service Outstanding Publication Award, he is the author or coauthor of more than 225 scientific papers and 20 books, including three volumes on bats, The Smithsonian Book of North American Mammals, Mammal Species of the World, and Handbook of Mammals of the World.

  CONTENTS

  Acknowledgments

  Introduction

  Species Included

  What Is a Species?

  What Information Is Included?

  What Information Is Not Included?

  Further Reading

  Recommended Internet Resources

  Using This Book to Identify a Mammal

  Quick Mammal ID Chart

  How Are Mammals Related?

  Mammal Measurements and Anatomy

  Species Plates

  Glossary

  Index

  ACKNOWLEDGMENTS

  The trick to writing a good field guide is to collect the scattered information on species identification and concentrate it into one concise volume. As a whole, North American mammals are a well-studied group, and the details in this book are largely a credit to the work produced by generations of mammalogists. Although books and journal articles provided some of this detail, no field guide could be completed without substantial research in natural history museums, and this guide is no exception. Our own institutions, the New York State Museum and the National Museum of Natural History, provided the collections, library facilities, and a wide variety of witting and unwitting ancillary support. In addition, we thank the Denver Museum of Nature and Science, the University of Colorado Museum, and the Field Museum, for access to their collections. A specimen in the drawer is much easier to bring to life when an expert helps point out the relevant characters. For this museum and identification help we thank:

  Greg Anderson, Andrea Bixler, Joe Bopp, Harold Broadbooks, Mike Carleton, Chris Conroy, Linda Gordon, Lawrence R. Heaney, Al Hicks, Rosanne Humphrey, Cheri A. Jones, Zack Knight, Bill Longland, Chris Maser, Jesus Maldonado, James Mead, Bruce Patterson, Jim Patton, Toni Piaggio, John Phelps, Roger A. Powell, Eric Rickart, Dave Schmidt, Michi Schulenberg, Andrew T. Smith, Bob Smith, William Stanley, and Westarp Wissenschaften. Additionally, we thank William Gannon for his assistance with chipmunk vocalizations, Dan Simberloff for his help with introduced species, and Al Hicks for plunging into caves to help us get the bats just right. Tim Page carefully read and corrected the entire text. A special thanks to Wade Sherbrooke and the staff at the Southwest Research Station for their hospitality during one of our field trips.

  The range maps were provided in a GIS for this field guide by Wes Sechrest. In collaboration with many conservation, museum, and academic groups including Conservation International, the Institute of Applied Ecology, and the International Union for the Conservation of Nature (IUCN), Sechrest has compiled distribution information for all mammal species in the world. The initial products, extent of occurrence maps for all mammal species, will soon be freely available on the new Species Information Service (SIS) of the IUCN.

  A field guide is part science and part art. For help and critique of artwork we thank:

  Catherine Chapm
an, Marlene Hill Donnelly, Ben Flemer, Patricia Kernan, Clara Richardson Simpson, David Steadman, and Karen Teramura, the staff at WILDlifeART, and Christa Wurm. Thanks to Keeping Track’s (www.keepingtrackinc.org) founder and Program Director Susan Morse for taking the time off their citizen-based wildlife monitoring, educational, and conservation programs to provide her expertise regarding the animal tracks and scat illustrations.

  We thank Greg Anderson, Tom Brooks, Chris Byrne, Chip Foster, Fritz Hertel, Barret Klein, Darrin Lunde, Chris Skelton, and John Young for insightful discussions about field guide design. Thanks to Ron Gill, Adam Fox, and Dimitri Karetnikov for computer help. Our editors at Princeton University Press, Sam Elworthy and Robert Kirk, gently pushed and pulled at appropriate points throughout the process, contributing greatly to the timely completion of the book.

  While the above offered their “perspiration,” we owe thanks to another suite of individuals for their inspiration and encouragement, especially Jim Findley, John Gittleman, Bonnie and David Kays, Deedra McClearn, Kevin McGowan, Karen Zich Reiss, and Bruce Patterson. Most importantly, we thank our wives Judy Kays and Kate Wilson, for their continuing graceful tolerance of our long hours in the field and museum over the years.

  INTRODUCTION

  A Moose crosses the road and traffic stops. Fearful campers scrutinize a Black Bear as it moves through their campsite. Even a mouse scurrying across the ground in the back yard will attract notice. Mammals command attention. Except for a few common species, most of our 462 mammal species are rarely seen; when they do show themselves, it can be quite exciting.

  Mammals arouse our emotions, often in contradictory ways. The fluffy Gray Squirrel is awfully cute, until it nests in your attic. The charismatic Wolf is a majestic symbol of wilderness, until it threatens your livestock. Depending on your point of view, a White-tailed Deer is a precious little Bambi, a trophy to be mounted on the wall, a hunk of meat to be sizzling on the grill, a pest that won’t leave your garden alone, or a 300-pound roadblock that could jump in front of your car at any moment.

  These anthropomorphic views are obvious, but the less obvious ecological duties fulfilled by our mammals may be even more important. The diverse ways in which they make a living means that they play myriad ecological roles that are at the very core of a healthy environment. Granivorous mammals (e.g. squirrels and mice) eat seeds, killing many potential plant offspring; but they also disperse some seeds away from the shade of the mother plant unharmed and into a good environment for germination. Thus they sometimes act as a friend of the plant, sometimes as a foe. Folivorous mammals (e.g. deer and rabbits) eat the leaves of plants and can keep certain species from overgrowing an area. Carnivorous mammals (e.g. weasels, Bobcats, and Killer Whales) keep their prey populations in check by eating the most abundant species. Predators can actually increase prey diversity by preventing a single species from becoming overabundant and driving others out. Insectivorous mammals (e.g. bats and shrews) help control insect populations, including many pest species. Our diverse and abundant mammal fauna constitute an important, well integrated part of our varied ecosystems.

  There are a number of reasons why one might want to identify a mammal, from idle curiosity to hard-core scientific inquiry. Anyone with a nose for nature will be curious about mammals encountered in the wild. The relative rarity of those encounters makes them all the more special, and our “biophilia,” or attraction to animals, carries with it a strong desire to identify whatever we see. For most of us, this book will serve as a handy guide in pocket or vehicle, for casual encounters with mammals. For others, it may be a useful companion on field trips or research projects designed to find and identify specific mammal species.

  SPECIES INCLUDED

  This field guide is designed to efficiently and accurately identify all 462 mammal species known from North America, north of Mexico. In addition to native species, this includes tropical species that rarely venture north across the border, exotic species introduced from foreign lands, and extinct species.

  Some species on our list have very rarely been recorded in North America (e.g. Margay and Hairy-legged Vampire Bat), but deserve coverage in a field guide so that naturalists know what to look for in the event that these species recolonize.

  Selecting which introduced mammal species to include in a field guide is a bit tricky. We selected only exotic mammal species known to survive and reproduce in the wild. This includes a number of ungulate and rodent species that could be confused with our native species. We decided not to include species such as the domestic horse or domestic cat, which have feral populations but are known to everyone, and unlikely to be confused with any native mammals. Because they are unlikely to be confused with native fauna, we did not include the various monkey species known to have escaped from zoos or breeding centers and that may survive in some areas in Florida, and perhaps Texas.

  WHAT IS A SPECIES?

  Scientists continue to refine our definition of the term species. Traditionally, we recognized independent evolutionary lineages that were reproductively isolated from other such lineages as species. This biological species concept is often difficult to apply in real life. Recent advances in molecular technology that allow much greater resolution of evolutionary relationships have led to a continuing re-examination of our ideas about what constitutes a species. For the purposes of this book, we have followed Wilson and Reeder (2005) in determining which species to recognize. In addition we have followed the more recent scientific literature and recognized a few additional species or name changes published subsequent to Wilson and Reeder (2005). So, for our purposes, a species is an evolutionary lineage of mammal that is recognized as distinct from other such lineages by appropriate authorities in the field of mammalogy.

  WHAT INFORMATION IS INCLUDED?

  We designed this book to be useful both to amateur naturalists and professional mammalogists. We have packed as much detail into this volume as possible, but also worked hard to keep it concise and efficient, so that it is not unwieldy in the field. All the information for a given species is displayed on two facing pages.

  ARTWORK

  The 110 color plates are the core of this guide and will be the most useful component for mammal identification. Each species is represented by an illustration, and some species have a number of illustrations to show variations in their appearance due to age, sex, season, or geographic variation. All paintings are original works of art created for this book and are the result of close collaboration between the artists and ourselves. Credits for each plate are listed on the copyright page.

  A NOTE ON SKELETAL MATERIAL

  Most species can be identified based on external appearances. However, sometimes two species of mammal can be distinguished only by a dental or skeletal character. In these cases we include an illustration of such differences.

  DISTRIBUTION MAPS

  The maps show the most recent geographic distribution data for each species. Data for these maps were provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy, Conservation International, World Wildlife Fund, and Environment Canada. Mammal ranges are dynamic, with some populations expanding into new areas and others becoming extirpated locally. Readers should therefore be on the lookout for species outside of their normal geographic range.

  SPECIES ACCOUNTS

  Each species account has a brief paragraph noting a species’ common name, scientific name, measurements, and details about appearance, general ecology, and behavior. All species accounts are written with a specific formula to make it easy to find the bit of information you are looking for:

  COMMON NAME Genus species total length, tail length, weight (with differences for male and female where significant)

  1) The single most important piece of information for identifying the species.

  2) Description of the physical traits of the species. Details of within-species variation and how to tell it apart fro
m similar species.

  3) Description of behavior, where relevant, including vocalizations.

  4) Description of habitats used by a species.

  SCAT ILLUSTRATIONS

  Mammals are often elusive, but their scat (feces) can be easy to find. This makes scat an excellent tool to document the presence of local mammals, and some mammalogists get quite excited over a good scat discovery. To aid in scat study, we have included examples of mammal scat shapes (see pages 236-239). While some species have very characteristic scats, others can be quite variable, with the shape and size dependent on the contents of the animal’s last meal. Generally, herbivores have more consistent diet, and therefore their scat can be more reliably identified. Carnivores and omnivores have more variable diets, and therefore are much more difficult to identify by scat alone.

  MAMMAL TRACKS

  Most big or medium-sized mammals have characteristic footprints that can be detected and identified in soft mud or snow. We have provided illustrations of these tracks, with a range of measurements, on the inside flap of the cover of this guide.

  WHAT INFORMATION IS NOT INCLUDED?

  While this book has all the information you need to identify every mammal species in North America, it does not have much more. To keep this field guide efficient to use, small, and easy to take into the field, we have minimized discussion about the ecology, behavior, evolution, and conservation of each species. We encourage readers to read more about the mammals they see and identify, and recommend the following sources for their bookshelves and coffee tables - but not necessarily for their field backpack.