Table Of Content

SEXUAL SEGREGATION IN UNGULATES Bowyer_Ungulates_int_4pgs.indd 1 18/08/22 12:12 AM Wildlife Management and Conservation Paul R. Krausman, Series Editor Bowyer_Ungulates_int_4pgs.indd 2 18/08/22 12:12 AM Sexual Segregation in Ungulates Ecol ogy, Be hav ior, and Conservation R. TERRY BOWYER Published in Association with THE WILDLIFE SOCIETY JOHNS HOPKINS UNIVERSITY PRESS | BALTIMORE Bowyer_Ungulates_int_4pgs.indd 3 18/08/22 12:12 AM © 2022 Johns Hopkins University Press All rights reserved. Published 2022 Printed in the United States of Amer i ca on acid- free paper 9 8 7 6 5 4 3 2 1 Johns Hopkins University Press 2715 North Charles Street Baltimore, Mary land 21218 www . press . jhu . edu Library of Congress Cataloging- in- Publication Data Names: Bowyer, R. Terry, author. Title: Sexual segregation in ungulates : ecol ogy, be hav ior, and conservation / R. Terry Bowyer. Description: Baltimore : Johns Hopkins University Press, 2022. | Series: Wildlife management and conservation | Includes bibliographical references and index. Identifiers: LCCN 2021063011 | ISBN 9781421445069 (hardcover) | ISBN 9781421445076 (ebook) Subjects: LCSH: Ungulates— Be hav ior. | Spatial be hav ior in animals. | Sex discrimination. Classification: LCC QL737.U4 B69 2022 | DDC 599.6— dc23/eng/20220120 LC rec ord available at https:// lccn . loc . gov / 2021063011 A cata log rec ord for this book is available from the British Library. Special discounts are available for bulk purchases of this book. For more information, please contact Special Sales at specialsales@jh . edu. Bowyer_Ungulates_int_4pgs.indd 4 18/08/22 12:12 AM To my wife, Karolyn Nothing would be pos si ble or enjoyable without her love and support Bowyer_Ungulates_int_4pgs.indd 5 18/08/22 12:12 AM This page intentionally left blank Contents Preface ix The Role of Resources and Predation Risk Acknowl edgments xiii in Gregariousness 31 Resources and Topography 31 1 Introduction and Overview 1 Predation 33 Historical Perspectives 1 3 Temporospatial Patterns 43 Ungulate Characteristics and Relevant Defining Social Groups 43 Aspects of Their Beh avi or, Ecolo gy, Attributes of Groups 44 and Conservation 2 Types of Social Groups 46 Distribution, Habitats, and Body Size 2 Temporal Patterns of Sexual Segregation Diets and Digestive Systems 2 and Aggregation 48 Mating Systems 3 Spatial Patterns of Sexual Segregation 50 Life- History Characteristics, Population Patterns on the Landscape 50 Dynamics, and Movements 4 Forage and Habitat Use, Se lection, Predator Pits, Apparent Competition, and and Quality 51 Territorial Regulation of Populations 5 Density Effects 55 Effects on Plants, Animals, and Nutrient Cycling 7 4 Detection and Mea sure ment 59 Trophic Cascades 8 Detecting Sexual Segregation 59 Cultural and Historical Relationships with Mea sur ing Sexual Segregation 60 Ungulates 9 Segregation Coefficients 60 Challenges Today and Future Unknowns 10 Sexual Segregation and Aggregation Sexual Segregation in Plants and Animals 12 Statistic 62 Tests of Ratios and Proportions 63 2 Differences between the Sexes 21 Multi- response Permutation Procedures 63 Definitions of Sexual Segregation 21 Information- Theoretic and Machine- Learning Sexual Differences in Morphology, Physiology, Approaches 63 and Foraging Be hav ior 22 Effects of Scale 64 Sexual Dimorphism 22 Habitat Se lection, Home Ranges, and Teeth Morphology and Diet 28 Scale 64 Gastrointestinal Characteristics and Related A Synthetic Approach 67 Physiology of Ruminants 29 Bowyer_Ungulates_int_4pgs.indd 7 18/08/22 12:12 AM viii contents 5 Failed Concepts 73 Predation- Risk Hypothesis 99 Setting Aside Rejected Hypotheses 73 Multiple Causations and Tradeoffs 100 Social Hypotheses 73 8 Consequences of Sexual Segregation for Ecological Hypotheses 76 Theory and Management 104 Limiting Overutilization of Habitats 78 Paternal Investment and Sexual Se lection 104 Problematical Speculations 78 Population Dynamics 105 Reproductive- Strategy Hypothesis 78 Forage- Selection Hypothesis 79 9 Failing to Consider Sexual Proximate Causations 79 Segregation 117 Avoiding More Speculation 81 Moose 117 6 The Role of Social Be hav ior 84 North American Elk 119 White- Tailed Deer 120 Social Aggression and Sexual Affinities 84 Bighorn Sheep 122 Activity Patterns 86 A Case Study of Mule Deer 88 10 The Future 128 Criticisms of the Activity-P attern Defining Sexual Segregation 128 Hypothesis 90 Why Is Sexual Segregation Overlooked? 129 The Social- Constraints Hypothesis 91 Future Questions and Directions 131 7 Ecological Aspects of Sexual Relevance to Other Organisms 133 Segregation 93 Competition Hypothesis 94 Lit er a ture Cited 137 Gastrocentric Hypothesis 97 Index 177 Niche- Partitioning Hypothesis 98 Bowyer_Ungulates_int_4pgs.indd 8 18/08/22 12:12 AM Preface For as long as I can remember, I have been fascinated I was fortunate that my master’s research at Hum- with large mammals. I suspect this attraction origi- boldt State University was supervised by David W. nated with my dad taking me out of school so I could Kitchen, an accomplished animal behaviorist who accompany our extended f amily on hunting trips for had just published his seminal monograph on prong- mule deer in California’s Sierra Nevada. At that time, horn. Dave was among a group of biologists begin- I was far too young to carry a r ifle. Nevertheless, I ning to integrate social be hav ior with ecol ogy. He read everyt hing I could about hunting, and when ma- convinced me to spend time watching Roos e velt elk ture enough to hike through rugged terrain and shoot at Gold Bluffs Beach in northern California, helped straight, I joined my dad hunting mule deer and quail me to understand elk beh avi or, and assisted with de- in the mountains outside of Ojai in southern Califor- veloping my critical thinking skills. My MS thesis nia. Early on, my enjoyment of hunting helped me concerned several aspects of elk beh avi or, but again, decide that I wanted to work with large mammals. it was restricted to observations during rut. I realized I was studying for my BS degree in wildlife man- that much of what we understood about animal agement, however, before I recognized that being beh avi or was not cast in an evolutionary perspective, a hunter, although teaching me field craft, was only a and there were many unanswered questions con- small part of what was required to be a scientist. Nev- cerning the links between ecolo gy and beh avi or. ertheless, without that early background, I might I did not become aware of sexual segregation never have become a field biologist. until I was studying southern mule deer in the I initially was not interested in sexual segregation; Cuyamaca Mountains of southern California for my I never recognized that this topic was a major com- doctoral dissertation at the University of Michigan ponent in the life histories of many large mammals (UM). My dissertation tested hypotheses about how (incidentally, hunters are not the only ones who lack resources and risk of predation helped shape the so- this appreciation). I had spent much of my time in cial organi zation of mule deer. My major professor, the field during autumn hunting seasons, which co- Dale R. McCullough, was studying the population incided with rut, when the sexes were mostly aggre- ecolo gy of white-t ailed deer in southern Michigan gated. Later on, I began to enjoy watching animals, when I arrived at the UM. A fter several years of rig- especially ungulates, without disturbing them, and orous coursework and thought-p rovoking discus- I was becoming increasingly more curious about sions, I fin ally had my fieldwork well underway and their be hav iors. was pursuing what I hoped would be cutting- edge Bowyer_Ungulates_int_4pgs.indd 9 18/08/22 12:12 AM