Food Unpredictability and Foraging

Abstract

All animals rely on food for energy, and the type of food they eat plays a fundamental role in shaping their behavior. Food varies in many ways: it may be abundant or scarce, mobile or sessile, spread evenly or found in dense clusters. The predictability of the spatial and temporal distribution of food also varies. In this chapter, we use empirical and theoretical examples from humans and other animals to examine how food predictability can influence many aspects of behavior related to foraging. In particular, we focus on feeding specialization, the use of sampling and information, food defense, and movement patterns. We argue that unpredictable food sources should drive animals to eat a wider variety of foods, increase their sampling rate, rely increasingly on others for information, share food rather than defend it, and increase their exploration and movement. These shifts may occur within one individual’s lifetime (through behavioral flexibility), or over many generations (through natural selection). We discuss strategies that species may use to make food more predictable, such as agriculture, hoarding, and excess storage of fat and outline the ways in which food predictability can impact health through increased stress or decreased immune responses. We include figures summarizing general principles of food predictability and its effects on individual behavior across a wide range of species. Several aspects of human behavior are considered within this context: the role of agriculture in increasing food predictability, the effects of food unpredictability on health, as well as the possible historical role of resource predictability in human brain evolution.