FORAGING BEHAVIOR AND COLONY STRUCTURE IN ANTS

Among social insects, foraging behaviour serves as a principal link in the translation between individual-level performance and colony-level success. Because nest size has been implicated as an important variab le in that translation, foraging behaviour was studied in an ant speci es that spontaneously changes its nest size over the summer. Effects o f queen presence/absence and nest size on speed, linearity and directi onality of movement were measured for (1) a series of undisturbed nest s and (2) nests that were altered in a pseudo-mutant experiment to sim ulate nest fractionation in the field. Ants looking for food behaved d ifferently for each of these three measures than did ants carrying foo d to the nest. Furthermore, nest size had strong effects on the behavi our of ants, but queen presence/absence was not a consistently importa nt factor. Our results show that an ant forager's behaviour reflects t he social milieu within her nest, even when she is outside that milieu . (C) 1996 The Association for the Study of Animal Behaviour