Foraging and Flocking Strategies: Information in an Uncertain Environment

Abstract

The effects of uncertainty and information on the foraging strategies of animals were investigated. It was argued that group foraging, or flocking, can increase individual feeding rates as a result of the sharing of information among group members. Members of a foraging group may experience reduced variation in their feeding rates. Both of these advantages increase with the scarcity and patchiness of the food supply. The informational advantages of flocking may tend to be dissipated by overflocking, which is in fact an evolutionarily stable strategy. (Possible defense strategies against overflocking, such as territorality or aggression, have not been considered here.) The strategy of individual foragers was discussed. The traditional analysis in terms of marginal values, residence times and giving-up times, may be misleading. It turns out to be important to probe, especially in patches where food abundance is highly variable. The marginal value theorem fails completely to reflect this aspect of uncertainty and information.