18 Spatial Aspects of Foraging in Ants and Bees

Abstract

Ants, bees and many species of wasps are central place foragers. They explore a home range surrounding a nest and bring finds home for communal use. Once home, honeybees pass on the nectar that they have collected to storer bees, who then deposit it in communal storage cells. Bumblebees empty their crops into communal honey pots. Leaf-cutter ants add leaf fragments to fungus gardens, and harvester ants store seeds in underground granaries. Many ants constantly pass collected food around, so that their individual stomachs form a communal storage space (Hölldobler and Wilson 1990), but often it is the larvae that form the greater part of the communal stomach (Hunt and Nalepa 1994). Filling these stores requires the effort of foragers that typically make up 5–25% of the colony (Seeley 1995). To carry out this task, social insects have developed a large array of individual and social strategies for locating, collecting, and transporting resources in different ecological conditions. Underlying the diversity of strategies are many common principles that allow colonies to exploit current sources reliably and efficiently while providing the flexibility to discover and switch to better sources.

The degree to which foraging is an individual or a communal endeavor varies considerably across species. An individual may accumulate its own particular spatial expertise and habits, navigating to familiar foraging grounds by following its own idiosyncratic but relatively direct and fixed route. In many species of ants (see, e.g., Hölldobler 1971), and some stingless bees (Lindauer and Kerr 1960; Nieh et...