Royal BC Museum Handbook BATS OF BRITISH COLUMBIA Second Edition CORI L. LAUSEN, DAVID W. NAGORSEN, R. MARK BRIGHAM AND JARED HOBBS VICTORIA, CANADA Also from the Authors of Bats of British Columbia Spotted Owls: Shadows in an Old-Growth Forest by Jared Hobbs and Richard Cannings Rodents and Lagomorphs of British Columbia by David Nagorsen Carnivores of British Columbia by David F. Hatler, David W. Nagorsen and Alison M. Beal Coming in 2023 Shrews and Moles of British Columbia by David Nagorsen and Nick Panter Bats of British Columbia Bats of British Columbia, second edition Text copyright © 2022 by Cori L. Lausen, David W. Nagorsen, R. Mark Brigham and Jared Hobbs. Photos copyright © the photographers as credited. Published by the Royal BC Museum, 675 Belleville Street, Victoria, British Columbia, V8W 9W2, Canada. The Royal BC Museum is located on the traditional territories of the Lekwungen (Songhees and Xwsepsum Nations). We extend our appreciation for the opportunity to live and learn on this territory. All rights reserved. No part of this book may be reproduced or transmitted in any form by any means without permission in writing from the publisher, except by a reviewer, who may quote brief passages in a review. Substantive editing by Annie Mayse Cover design, interior design and typesetting by Jeff Werner Index by Stephen Ullstrom Library and Archives Canada Cataloguing in Publication Title: Bats of British Columbia / Cori L. Lausen, David W. Nagorsen, R. Mark Brigham and Jared Hobbs. Names: Nagorsen, David W., author. | Lausen, Cori Lorraine, 1971- author. | Brigham, Robert Mark, 1960- author. | Hobbs, Jared, 1971- author. Series: Royal British Columbia Museum handbook. Description: Second edition. | Series statement: Royal BC Museum handbook | First edition authored by: David W. Nagorsen, R. Mark Brigham. | Includes bibliographical references and index. Identifiers: Canadiana (print) 20210353503 | Canadiana (ebook) 2021035352X | ISBN 9780772679932 (softcover) | ISBN 9780772679949 (EPUB) Subjects: LCSH: Bats—British Columbia. | LCSH: Bats—British Columbia—Identification. Classification: LCC QL737.C5 N34 2022 | DDC 599.409711—dc23 Contents Preface vii Introduction 1 Origins and Classification 2 Taxonomy and Nomenclature 4 What Is a Species? 6 Checklist of BC Bats 8 Bats in BC 9 General Biology 13 Morphology 13 The Nubby-Ear Mystery 18 Using Sound to Locate Prey and Navigate in the Dark 22 Food and Water 24 Reproduction, Young and Longevity 28 Torpor and Roost Selection 32 Summer Roosting Sites 36 Hibernation and Winter Ecology 45 Winter Roosting Sites (Hibernacula) 51 Disease and Bats 52 Conservation and Threats 57 Two Provincial Designations—Not Enough to Protect Bat Habitat 65 Collisions with Cars 69 Studying Bats 73 Identifying BC’s Bats 91 In-Hand Differentiation 92 Acoustics—Echolocation and Species Identification 103 Species Accounts 129 Pallid Bat 135 Townsend’s Big-Eared Bat 147 Big Brown Bat 159 Spotted Bat 169 Eastern Red Bat 179 Hoary Bat 187 Silver-Haired Bat 197 Californian Myotis 207 Long-Eared Myotis 217 Little Brown Myotis 227 Dark-Nosed Small-Footed Myotis 239 Northern Myotis 247 Fringed Myotis 255 Long-Legged Myotis 263 Yuma Myotis 271 Accidental Species 283 Brazilian Free-Tailed Bat 285 Big Free-Tailed Bat 291 Canyon Bat 295 Acknowledgements 299 Appendix 1: Other Species Referred to in Text 301 Appendix 2: Key to Skulls and Dental Traits of BC Bats 302 Appendix 3: Reference Table for Species Morphology 308 Appendix 4: Acoustic Species Summary Table 311 Appendix 5: Fun Bat Facts 318 Glossary 321 References 331 Index 355 About the Authors 373 Cori Lausen examines the radio transmitter glued to this spotted bat before releasing it. Using radio receivers and a helicopter, researchers tracked this bat to a rock crevice high in a cliff wall along the Fraser River—the first spotted bat maternity roost discovered in this area. vi Contents Preface The first edition of Bats of British Columbia, by David W. Nagorsen and R. Mark Brigham, was published in 1993. After three printings, it went out of print. Since then, an explosion in field studies of the province’s bat fauna, applying new tools, such as genetic techniques and acoustic bat detectors, has added a wealth of new knowledge. Additionally, bat distributions shift and new species have been documented in the province. It is therefore time for a new edition, updating British Columbia’s species list and range maps, and describing new ecological, genetic and behavioural findings. We present new keys for differentiating species morphologically and acoustically, and have incorporated a whole new section on bat echolocation, using bat detectors as tools for differentiating species and monitoring populations. As with the 1993 handbook, much of the information in this edition is directed toward a general audience, biologists new to the study of bats, and naturalists, with emphasis on identification, natural history, distribution and conservation. As terminology may be unfamiliar to some readers, we have included an extensive glossary, with glossary terms in coloured font the first time they appear in the text. Although the book is focused on the bat fauna of BC, most of the species covered occur in other parts of the western United States, Canada and Alaska, and some also occur in eastern North America. One major change in this edition is the use of colour images throughout the book; unless otherwise noted in a photo credit, all of the photos in the book were taken by Jared Hobbs before the COVID-19 pandemic. We have made many changes to the text. The introductory General Biology chapter has been completely revised to reflect new information about bats in BC. We’ve expanded the Conservation section to describe new threats from the white-nose syndrome fungus and bat fatalities at wind energy sites. The Identifying BC’s Bats chapter has been enhanced with colour images of diagnostic traits. With the integration of bat detectors and mobile devices, such as smartphones, recording bat sounds is now possible for citizen scientists. We have therefore included an entirely new section on echolocation to guide readers on the use of acoustic sounds recorded with bat detectors, and each species account now has a subsection on acoustic identification. Other revisions within the species accounts include updated colour range maps, spectrograms illustrating the species’ echolocation call characteristics, and conservation status. In addition to the 15 bat species that occur in BC, three bats (two only recently discovered) are covered in an Accidental Species section with their own species accounts. Preface vii While there is something in the book for all audiences, it should be stressed that live bats and bats found dead should only be handled (e.g., for purposes of species identification, including measurements) by qualified individuals who have been vaccinated for the rabies virus (see Disease and Bats, page 52). We hope this book will create an appreciation for this fascinating group of mammals and provide impetus for their conservation. Gray-headed flyinG fox is a megabat endemic to forested areas of southeastern Australia. viii Preface Introduction Folklore generally portrays bats negatively. Their close association with the darkness of night has undoubtedly fostered this negative image. Unfortunately, bats are all too often regarded as blood-sucking, parasite-ridden, disease- carrying vermin; all of these assertions are incorrect. As our understanding of bat ecology has improved, we have also gained an understanding of bats as “keystone” species—species that play key roles in shaping the ecosystems of which we are a part. Around the globe, bats fulfill several important ecological roles—controlling insect populations, pollinating plants, dispersing seeds and even providing humans with medicines (e.g., the vampire bat’s saliva is used as an anticoagulant to treat human stroke victims) and avenues for medical research (e.g., bat longevity is being studied to understand how humans might live longer). Yet despite their importance to the planet’s ecosystems, there remains more misinformation than fact and more fear than respect for these diminutive guardians of the night. Bats are a diverse group of relatively long-lived, slow-reproducing mammals. There are more than 1,400 species of bats worldwide. They occupy every continent except Antarctica and can be found in virtually every type of habitat, from desert to forest. Although bat diversity is highest in tropical and subtropical regions, bats have been incredibly successful at colonizing a diverse array of ecological niches over almost all parts of the globe, with the exception of the polar regions. Although the vast majority of bats are small, weighing less than 50 grams (equivalent to seven loonies; all BC bats fall into this category), they do come in a large range of sizes. The largest are the flying foxes of Asia, Africa and Australia, which may attain a body mass of more than 1 kilogram and a wingspan of 2 metres (see image on facing page). Despite their formidable size, flying foxes are harmless fruit-eaters. The smallest bat in the world is the rare Bumblebee Bat of Thailand, with a mass of about 2 grams and a wingspan of 15 centimetres. About three-quarters of the world’s bats consume insects and other invertebrates, but there are species in the tropics that prey on vertebrates, such as frogs, reptiles, fish, birds and small mammals, including other bat species. The most specialized of all the mammalian predators are the three species of vampire bats of the New World continents (North and South America), which feed exclusively on the blood of birds and mammals. It could be argued that using the word bat has been counterproductive to bat conservation. Use of this broad term, encompassing such a diverse group of animals, may draw attention away from the differences that exist among bat species in their foraging and drinking habitat requirements and, most I ntroduction 1