RISK AND FORAGING IN STOCHASTIC ENVIRONMENTS

Abstract

Foraging animals confront problems conceptually similar to those facing an economically minded consumer (46, 47), and foraging theory shares a methodology in common with economics. Indeed, the last 20 years have seen wide application of economic models in biology. A growing consensus suggests that ecological and economic theories are ultimately indistinguishable (6, 30). Economic analyses begin with an economic agent that chooses from alternative objects or activities. The analyst extracts a set of measurable attributes from this collection of objects (e.g. energy content, costs, etc) that are combined into a single index. This index has the property that objects whose attributes generate higher values are preferred by the consumer over objects generating lower values. In economics, this index (the 'utility function') is the basic organizing principle (36). Behavioral ecologists use this technique to learn what attributes should be included in an organism's utility function to determine how various attributes should be combined and weighted, and then to predict choices by maximizing the utility function under applicable constraints. The organism's utility function is, therefore, both an object of empirical study and a predictive tool. Economic analysis usually stops here, but evolutionary biologists go farther. They assume that the organisms' preferences are related to evolutionary fitness and that the options