Flock Dynamics: Patterns of Arrival and Departure

Abstract

Being in a group affects the way individuals behave. In our case, single- and mixed-species flocking affect the way birds allocate time to behaviours associated with feeding and looking for predators, and this directly affects their feeding efficiency (Chapters 5 and 6). Since the effect on individual feeding efficiency depends on the size and species composition of the flock, we might expect birds to be selective about the flocks they join or remain in to feed. Indeed, from a knowledge of the relationship between flock size and composition on the one hand and individual time budgeting and feeding efficiency on the other, we should be able to predict the probability that a bird will join, remain in or leave any given flock. This should then allow us to predict the way particular flocks will build up. In other words, the dynamics of a feeding flock should be predictable from its effects on individual behaviour.