Table Of ContentRoyal 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
