Dietary composition of birds species at an inland airport in South Africa

Abstract

Stomach contents of 51 bird species that posed a potential threat to aviation were collected at the Bloemfontein airport over a period of 11 years (1985-1995). Numerically the crowned plover (Vanellus coronatus), and the lesser kestrel (Falco naumanni), blacksmith plover (V. armatus), whitewinged korhaan (Eupodotis afraoides), doublebanded courser (Smutsornis africanus), spotted dikkop (Burhinus capensis), cattle egret (Bubulcus ibis), Swainson’s francolin (Francolinus swainsonii) and Orange River francolin (F. levaillantoides) in sequence of importance, constituted 91,0% of the total sample (3 544). In general insects can be considered the main food source of the birds concerned. Based on dry mass composition the Isoptera, followed by the Coleoptera and Orthoptera, constituted the most important component in the diet. The Isoptera, more specifically the harvester termite (Hodotermes mossambicus), is, moreover, the only important prey taxon showing a conspicuous utilisation peak during the relative food shortage of the dry season. Evidently, temporary superabundant food sources that periodically come about in grassland habitats are opportunistically utilised by the birds.