Research Techniques in Animal Ecology Methods and Cases in Conservation Science Mary C. Pearl, Editor Methods and Cases in Conservation Science Tropical Deforestation: Small Farmers and Land Clearing in the Ecuadorian Amazon Thomas K. Rudel and Bruce Horowitz Bison: Mating and Conservation in Small Populations Joel Berger and Carol Cunningham, Population Management for Survival and Recovery: Analytical Methods and Strategies in Small Population Conservation Jonathan D. Ballou, Michael Gilpin, and Thomas J. Foose, Conserving Wildlife: International Education and Communication Approaches Susan K. Jacobson Remote Sensing Imagery for Natural Resources Management: A First Time User’s Guide David S. Wilkie and John T. Finn At the End of the Rainbow? Gold, Land, and People in the Brazilian Amazon Gordon MacMillan Perspectives in Biological Diversity Series Conserving Natural Value Holmes Rolston III Series Editor, Mary C. Pearl Series Advisers, Christine Padoch and Douglas Daly Research Techniques in Animal Ecology Controversies and Consequences Luigi Boitani and Todd K. Fuller Editors C COLUMBIA UNIVERSITY PRESS NEW YORK Columbia University Press Publishers Since 1893 New York Chichester, West Sussex Copyright © 2000 by Columbia University Press All rights reserved Library of Congress Cataloging-in-Publication Data Research techniques in animal ecology : controversies and consequences / Luigi Boitani and Todd K. Fuller, editors. p. cm. — (Methods and cases in conservation science) Includes bibliographical references (p. ). ISBN 0–231–11340–4 (cloth : alk. paper)—ISBN 0–231–11341–2 (paper : alk. paper) 1. Animal ecology—Research—Methodology. I. Boitani, Luigi. II. Fuller, T. K. III. Series. QH541.2.R47 2000 591.7′07′2—dc21 99–052230 ϱ Casebound editions of Columbia University Press books are printed on permanent and durable acid-free paper. Printed in the United States of America c 10 9 8 7 6 5 4 3 2 1 p 10 9 8 7 6 5 4 3 2 1 For Stefania and Caterina and Susan and Mollie for their patience, love, and support Contents authors xv list of illustrations xix list of tables xxiii preface xxv Chapter 1: Hypothesis Testing in Ecology Charles J. Krebs 1 Some Definitions 1 What Is a Hypothesis? 3 Hypotheses and Models 4 Hypotheses and Paradigms 6 Statistical Hypotheses 8 Hypotheses and Prediction 10 Acknowledgments 12 Literature Cited 12 Chapter 2: A Critical Review of the Effects of Marking on the Biology of Vertebrates Dennis L. Murray and Mark R. Fuller 15 Review of the Literature 16 Which Markers to Use? 17 Effects of Markers Among Taxa 17 Critique of Marker Evaluation Studies 35 Review of Current Guidance Available for Choosing Markers 37 Critique of Guidelines Available for Choosing Markers 39 viii CONTENTS Survey of Recent Ecological Studies 40 Future Approaches 42 Study Protocols and Technological Advances 43 Marker Evaluation Studies 44 Acknowledgments 46 Literature Cited 46 Chapter 3: Animal Home Ranges and Territories and Home Range Estimators Roger A. Powell 65 Definition of Home Range 65 Territories 70 Estimating Animals’ Home Ranges 74 Utility Distributions 75 Grids 77 Minimum Convex Polygon 79 Circle and Ellipse Approaches 80 Fourier Series 80 Harmonic Mean Distribution 81 Fractal Estimators 82 Kernel Estimators 86 Home Range Core 91 Quantifying Home Range Overlap and Territoriality 94 Static Interactions 95 Dynamic Interactions 97 Testing for Territoriality 98 Lessons 100 Acknowledgments 103 Literature Cited 103 Chapter 4: Delusions in Habitat Evaluation: Measuring Use, Selection, and Importance David L. Garshelis 111 Terminology 112 Methods for Evaluating Habitat Selection, Preference, and Quality 114 Use–Availability Design 114 Site Attribute Design 117 Demographic Response Design 118 Problems with Use–Availability and Site Attribute Designs 118 CONTENTS ix Defining Habitats 118 Measuring Habitat Use 120 Measuring Habitat Availability 122 Assessing Habitat Selection: Fatal Flaw 1 127 Inferring Habitat Quality: Fatal Flaw 2 139 Advantages and Problems of the Demographic Response Design 144 Applications and Recommendations 147 Acknowledgments 153 Literature Cited 153 Chapter 5: Investigating Food Habits of Terrestrial Vertebrates John A. Litvaitis 165 Conventional Approaches and Their Limitations 166 Direct Observation 166 Lead Animals 167 Feeding Site Surveys 167 Exclosures 170 Postingestion Samples 170 Evaluating the Importance of Specific Foods and Prey 175 Use, Selection, or Preference? 175 Availability Versus Abundance 175 Cafeteria Experiments 176 Innovations 176 Improvements on Lead Animal Studies 176 Use of Isotope Ratios 177 Experimental Manipulations 177 The Role of Foraging Theory in Understanding Food Habits 179 Lessons 181 Sample Resolution and Information Obtained 181 Improving Sample Resolution and Information Content 182 Literature Cited 183 Chapter 6: Detecting Stability and Causes of Change in Population Density Joseph S. Elkinton 191 Detection of Density Dependence 193 Analysis of Time Series of Density 193 Analysis of Data on Mortality or Survival 196 Detection of Delayed Density Dependence 199 x CONTENTS Detection of Causes of Population Change 201 Key Factor Analysis 201 Experimental Manipulation 205 Conclusions 208 Literature Cited 209 Chapter 7: Monitoring Populations James P. Gibbs 213 Index–Abundance Relationships 214 Types of Indices 214 Index–Abundance Functions 215 Variability of Index–Abundance Functions 217 Improving Index Surveys 220 Spatial Aspects of Measuring Changes in Indices 221 Monitoring Indices Over Time 222 Power Estimation for Monitoring Programs 223 Variability of Indices of Animal Abundance 224 Sampling Requirements for Robust Monitoring Programs 227 Setting Objectives for a Monitoring Program 228 Conclusions 229 Acknowledgments 232 Appendix 7.1 233 Literature Cited 247 Chapter 8: Modeling Predator–Prey Dynamics Mark S. Boyce 253 Modeling Approaches for Predator–Prey Systems 254 Noninteractive Models 255 True Predator–Prey Models 260 Stochastic Models 269 Autoregressive Models 270 Fitting the Model to Data 273 Bayesian Statistics 273 Best Guess Followed by Adaptive Management 273 Choosing a Good Model 275 How Much Detail? 275 Model Validation 277 Recommendations 279 Remember the Audience 279 CONTENTS xi Conclusion 281 Acknowledgments 281 Literature Cited 282 Chapter 9: Population Viability Analysis: Data Requirements and Essential Analyses Gary C. White 288 Qualitative Observations About Population Persistence 290 Generalities 290 Contradictions 292 Sources of Variation Affecting Population Persistence 293 No Variation 293 Stochastic Variation 293 Demographic Variation 295 Temporal Variation 297 Spatial Variation 300 Individual Variation 300 Process Variation 303 Components of a PVA 303 Direct Estimation of Variance Components 305 Indirect Estimation of Variance Components 312 Bootstrap Approach 313 Basic Population Model and Density Dependence 314 Incorporation of Parameter Uncertainty into Persistence Estimates 319 Discussion 322 Conclusion 325 Literature Cited 327 Chapter 10: Measuring the Dynamics of Mammalian Societies: An Ecologist’s Guide to Ethological Methods David W. Macdonald, Paul D. Stewart, Pavel Stopka, and Nobuyuki Yamaguchi 332 Social Dynamics 332 Context 334 Why Study Social Dynamics? 335 Evolution of Sociality 335 Conservation Applications 335 Understanding Ourselves 336 How to Describe Social Dynamics 337 xii CONTENTS Action, Interaction, and Relationships 337 Social Networks 338 Social Structure, from Surface to Deep 339 Behavioral Parameters 340 The Bout 340 Stationarity 343 The Ethogram 343 Beware Teleology 345 Classifications of Behavioral Interactions 347 Methods for Behavioral Measurement 362 Identifying the Individual 362 Sampling and Recording Rules 364 Ad Libitum Sampling 365 Focal Sampling 365 Time Sampling 366 Techniques for Behavioral Measurement 368 Analysis of Observational Data 369 Statistical Rationality 370 Matrix Facilities: Analyzing Sequential Data 371 Lag Sequential and Nested Analysis 374 Searching for a Behavioral Pattern (Markov Chain) 375 Predictability of Behavior 376 Sequences Through the Mist 378 Acknowledgments 380 Literature Cited 380 Chapter 11: Modeling Species Distribution with GIS Fabio Corsi, Jan de Leeuw, and Andrew K. Skidmore 389 Terminology 391 Habitat Definitions and Use 392 General Structure of GIS-Based Models 396 Literature Review 401 Modeling Issues 403 Clear Objectives 403 Assumptions 405 Spatial and Temporal Scale 408 Data Availability 412 Validation and Accuracy Assessment 413 CONTENTS xiii Discussion 422 Conclusions 424 Acknowledgments 425 Notes 425 Literature Cited 426 index 435 Authors Luigi Boitani Dipartimento Biologia Animale dell’Uomo Università di Roma “La Sapienza” Viale Università 32 00185 Rome, Italy Mark S. Boyce Department of Biological Sciences University of Alberta Edmonton, Alberta T6G 2E9, Canada Fabio Corsi Institute of Applied Ecology (IAE) Via L. Spallanzani 32 00161 Rome, Italy Joseph S. Elkinton Department of Entomology and Graduate Program in Organismic and Evolutionary Biology University of Massachusetts Amherst, MA 01003, USA xvi AUTHORS Mark R. Fuller USGS Forest and Rangeland Ecosystem Science Center Snake River Field Station and Boise State University 970 Lusk Street Boise, ID 83706, USA Todd K. Fuller Department of Natural Resources Conservation and Graduate Program in Organismic and Evolutionary Biology University of Massachusetts Amherst, MA 01003-4210, USA David L. Garshelis Minnesota Department of Natural Resources 1201 E. Highway 2 Grand Rapids, MN 55744, USA James P. Gibbs State University