Hormones and Animal Social Behavior

Elizabeth Adkins-Regan is Professor of Psychology and Professor of Neurobiology and Behavior at Cornell University.

"Elizabeth Adkins-Regan takes the reader sledding from brain behavior and from hormones to gene expression, up and down through levels of analysis that often change within a single sentence."--Ellen D. Ketterson, Science "Hormones and Animal Social Behavior masterfully achieves Adkins-Regan's goal of integrating behavioral endocrinology with ecological and evolutionary studies... I predict that this outstanding book will soon become a classic in behavioral biology."--Randy J. Nelson, BioScience "Adkins-Regan's book is a timely and very welcome contribution that will be hoped to set the standards for the study of the neuroendocrinological basis of behavior in the wild."--Aldo Poiani, Austral Ecology

• List of Illustrations and Tables ix Preface xiii Chapter 1: Hormonal Mechanisms 1 Why Does Social Behavior Need Hormonal Regulation? 3 Steroids 4 Steroid Synthesis and Metabolism 7 Steroid Measurement and Dynamics 9 Neuropeptides and Prolactin 11 Where and How Do Steroids Act to Alter Behavior? 13 Steroid Manipulation 18 Mechanisms of Peptide Action 19 Multiple Messengers,Multiple Behaviors 20 Hormones,Plasticity,and Development 21 How the Necessary Control of Steroids by the Environment Is Achieved: The HPG and HPA Axes 23 Diversity in Mechanisms 29 How "Costly" Are These Hormonal Mechanisms? 30 Chapter 2: Mating, Fighting, Parenting, and Signaling 34 Courtship and Mating 34 Individual and Species Variation in Hormone Dependence of Mating Behavior 42 Female Mating Behavior and Sex Differences in Hormone Dependence 44 Aggressive Behavior 49 Parental Behavior 52 How Hormones Alter Behavior: Circuits, Networks, and Processes 58 Daily and Seasonal Rhythms of Social Behavior 65 Hormones and Signaling 71 Hormonal Responses to Signals and Cues 82 Chapter 3: Social Relationships and Social Organization 92 Sociality 93 Dominance 94 Territoriality 98 Mating Systems 102 Mate Choice 108 Pairbonding 112 Parent -Offspring and Sibling Relationships 117 Cooperative Breeding and Alloparenting 122 Conclusions 130 Chapter 4: Development of Sexes and Types 131 Sex Determination and Morphological Sexual Differentiation 131 Sex Differences in Behavior and Brains 135 Sex Differences Due to Activational Hormone Effects 138 The Organization of Behavioral Sex Differences in Mammals 139 The Direct Genetic Differentiation Hypothesis 146 The Development of Sex Differences in Birds: Progress and Puzzles 148 Sexual Differentiation of Behavior in Other Vertebrates 155 Do Invertebrates Have Hormonally Organized Sex Differences in Behavior? 158 Sex-Changing Fish 160 Within-Sex Types (Within-Sex Dimorphism) 165 Comparative Overview 172 Chapter 5: Evolutionary Change and Species Differences 179 Heritable Phenotypic Variation: Individual Differences and Their Basis 179 Reproductive Success and Differential Fitness 187 Responses to Selection 193 Correlated Traits, Hormones,Costs, and Evolutionary Change 200 Hormones,Sexes,and Sexual Selection 202 Putting Hormonal Mechanisms in the Foreground 205 Genetic Architecture and Hormonally Based Sexual Dimorphism 213 The Perspective from Evolutionary Developmental Biology 214 Species Comparisons in Hormones and Behavior 218 Conclusions 222 Chapter 6: Life Stages and Life Histories 224 Life Histories,Fitness,and Hormones 224 Life Stages Prior to Reproductive Maturity 226 Onset of Reproductive Maturity: Puberty 233 Aging and Senescence 239 Hormones,Social Behavior, and Life History Trade-Offs 247 Conclusions 255 Chapter 7: Phylogeny:Conservation and Innovation 256 Oxytocin Family Peptides and Their Receptors 256 GnRH and Its Receptors 260 Steroid Receptors 263 Steroids and Steroidogenic Enzymes 266 Behavioral Phylogeny, Brains, and the Conservation Paradox 269 Steroid-Modulated Vocalization 272 Mating Behavior 276 Parental Behavior 277 Sex Determination and Sexual Differentiation 279 Conclusions 283 Afterword 285 References 287 Index 365