Forager abundance and dietary relationships in a Namib Desert ant community

Abstract

Thirteen ant species coexist on a barren gravel plain habitat in the central Namib Desert. Numerical density of foragers of all species fluctuated considerably over a 17-month period. Peaks in abundance correlated to rainfall events and hence primary production pulses. The majority of foragers were nocturnal in summer and diurnal in winter. The community was dominated in terms of species, forager abundance and biomass by myrmicine, seed-harvesting ants. There was considerable intra-and interspecific variation in diet through time and no consistent patterns were apparent. Diet niche breadth and overlap also exhibited considerable variation between species at any one time and within a species through time. There was no consistent relationship between ant size and the size of food particle utilized. Namib Desert ants are highly opportunistic and the lack of consistent patterns suggests that interspecific competition for food is not likely to be of major importance in this community.