Feeding ecology of the Southern Bald Ibis, Geronticus calvus, in the Free State, South Africa

Abstract

The feeding ecology of the Southern Bold Ibis, Geronticus calvus, was studied in the Free State Province, South Africa, during two breeding seasons in 1994 and 1996. Fields of harvested maize, burnt grass and overgrazed pastures are the main feeding habitats of the birds in this region throughout the breeding season. The ibises forage mainly in flocks ranging from 2 to 24 birds (x = 5), often in association with cattle and other animals. Analysis of stomach contents, pellet contents and food remnants revealed that larvae of Busseola fusca (Lepidoptera: Noctuidae) and imagos of Coleoptera constitute the staple food. These larvae were collected from maize stalks trampled by cattle, while Coleoptera were collected mainly from dung, grass clumps and from the ground in pastures. A considerable amount of inorganic matter, such as pieces of glass, porcelain, plastic, metal, buttons and gravel, was also found.