Abundance of ants and termites in the False Karoo and their importance in the diet of the aardvark Orycteropus afer

Abstract

ummary The seasonal abundance of ant and termite species was compared with their occurrence in aardvark faeces on Tussen-die-Riviere Game Farm in the False Karoo, South Africa. Ants and termites were sampled from four vegetation communities in summer and winter using pitfall traps. Fresh aardvark faeces were collected and analysed. Of 2360 specimens collected in the traps 2172 (92%, 34 species) were ants and 188 (8%, two species) were termites. Anoplolepis custodiens accounted for 44·9% of all specimens collected. Aardvark faeces contained only thirteen species of ants and two species of termites. Of these, three hypogaeic ant species had not been found in pitfall samples probably due to their subterranean habit. In common with the traps, A. custodiens was the most dominant prey species in both seasons while ants comprised 71% of the diet and termites 21%. The remainder of the diet in each season consisted of seeds and fly puparia. Aardvark appear to feed readily on both ants and termites yet concentrate on the most abundant species available. Resume L'abondace saisonniere d'especes de fourmis et de termites a ete comparee avec leur presence dans les excrements d'orycteropes a la Tussen-die-Rivieren Game Farm, dans le False Karoo, en Afrique du Sud. Les fourmis et les termites ont ete recoltes dans des pieges, dans quatre communautes vegetales, en ete et en hiver. On a recolte et analyse les excrements frais d'orycteropes. Des 2360 specimens recoltes dans les pieges, 2172 (92%, 34 especes) etaient des fourmis et 188 (8%, 2 especes), des termites. Anoplolepis custodiens comptait pour 44,9% de tous les specimens collectes. Les excrements d'orycteropes ne contenaient que treize especes de fourmis et deux de termites. Parmi celles-ci, trois especes de fourmis souterraines n'avaient pas ete trouvees dans les pieges, sans doute a cause de leur mode de vie souterrain. Comme dans les pieges, A. custodiensetait la proie principale pendant les deux saisons; les fourmis representaient 71% du regime alimentaire, et les termites 21%. A chaque saison, le reste du regime se composait de graines et de larves d'insectes. L'orycterope semble se nourrir aussi volontiers de fourmis que de termites et manger plutot les especes qui se trouvent etre les plus abondantes.