ABSTRACT
This chapter examines variation in foraging patterns within and among colonies of the western harvester ant, Poqonomyrmex occidentalis, in response to variation in vegetational structure. It describes a model to explain how flexibility can increase foraging efficiency at the level of the colony and at the level of the individual. The chapter explores intercolonial differences in the foraging system of P. occidentalis and their relation to vegetation cover surrounding the nests. It describes the hypotheses that foraging strategy varies among colonies in a population, and this variation can be predicted by the variation in vegetational density around the nest, measured as percent vegetational cover. The chapter also examines longitudinal changes in foraging strategy within colonies in response to changes in food type availability and distribution. Ants may vary foraging patterns to increase foraging efficiency in complex or changing environments. In particular, ant foraging patterns may be influenced by vegetational structure, which can vary spatially and temporally.
