ECOLOGY AND BEHAVIOR OF THE SEED-EATING PONERINE ANT BRACHYPONERA-SENAARENSIS (MAYR)

Colonies of Brachyponera senaarensis, a species known for its adaptation to dry tropical conditions in Sudanes savannas, can also flourish in a wet tropical environment if it is particularly sunny and well-drained, e.g. in sandy regions. The feeding strategy of this species is opportunistic, with great flexibility of nesting, foraging, and diet according to the nature of the environmental constraints. Swarming takes place at the height of the rainy season. Foundation is partially claustral and haplometrotic or, more rarely, pleometrotic. Daily foraging activity of workers, which is mainly diurnal, peaks between 07:00 h and 09:00 h and then ceases between 11:00 h and 14:00 h. The size of workers varies between colonies, depending on the richness of their environment. Moreover, two worker subcastes may be distinguished in a colony: (1) individuals which are nonpigmented at birth and represent the majority of the worker population; and (2) larger workers, whose level of maturation is more advanced both morphologically and behaviorally, as shown by an age-polyethism study.