Diet of the African black oystercatcher Haematopus Moquini on rocky shores: spatial, temporal and sex-related variation

Abstract

The diet of the African black oystercatcher Haematopus moquini was investigated throughout the species' range. Variation in diet is related to time, place and sex of the bird. Principal prey species on the west coast are mussels Choromytilus meridionalis and Aulacomya ater , and limpets Patella granularis and P. argenvillei . The mussel Perna perna predominates in the diet on the south and south-east coasts. Less food is taken by night than by day, and at night the nocturnally active Patella granularis forms a much greater proportion of the diet than by day. An increasing proportion of mussels and correspondingly fewer limpets are fed to chicks as they grow older. Territorial pairs reduce potential intersexual competition for food by removing prey in differing relative proportions; males take more limpets and whelks while females take a greater proportion of polychaetes and whelks while females take a greater proportion of polychaetes and small unshelled items.