Foraging

CHAPTER

9

Foraging CHAPTER OUTLINE 9.1 Introduction  254 9.2 Diet Choice and Food Selection  255 What Is an Adequate Diet?  255 Essential Nutrients  256 Digestion of Cellulose  256

9.3 How Animals Get Food  257 Trophic Strategies and Styles of Foraging  257 Styles of Herbivory  257 Overcoming Plant Defenses  259 Active Hunters  260 Sit and Wait Predation  262 Omnivory  262 Mimicry and Luring  262 Cooperative Hunting  263 Uninvited Guests during Foraging  264

9.4 Willing Food  264 Predator Saturation  264 Saprophagy  264

9.5 Manipulation of Prey  265 9.6 Parasitic Life Cycles  266 9.7 Foraging and Optimality Theory  268 9.8 Optimal Patch Choice  270 The Marginal Value Theorem  270 Central Place Foraging  272 Risk Sensitivity  272

9.9 Optimal Prey Choice  274 9.10 Nutritional Constraints  275 Summary  276 Study Questions  277 Further Reading  277

LEARNING OBJECTIVES Studying this chapter should provide you with the knowledge to: l See how dietary requirements, natural selection for dietary specialization, and the evolution of foraging behavior interact. l Understand the diversity of dietary strategies employed by animals. l Be able to use optimality theory to test and refine hypotheses about important resources—the currencies of animal lives. In the study of foraging, this is frequently energy. l Understand the limits of optimality theory; animals are not expected to optimize every behavior. These constraints are the same as those that make adaptation and natural selection works in progress rather than finished portraits.

Animal Behavior. © 2012 Elsevier Inc. All rights reserved.

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