Diet, body mass and condition of Lesser Kestrels Falco naumanni in South Africa

Abstract

Anderson, P.C., Kok O.B. & Erasmus, B.H. 1998. Diet, body mass and condition of Lesser Kestrels Falco naumanni in South Africa. Ostrich 70(2):112-116. A total of 229 Lesser Kestrels Falco naumanni shot by airport personnel as part of their bird control programme, was obtained from the Bloemfontein and Kimberley airports during the 1984/85, 198986 and 1986/87 austral summers. Analysis of stomach contents of non-breeding individuals visiting South Africa's Free State and Northern Cape Provinces indicated that Arthropoda comprise 90% of the diet, with Solifugae (30%), Orthoptera (23%). Chilopoda (20%) and Isoptera (10%) being the most important food items. Vertebrates were virtually absent from the diet. No sex-related dietary differences were found. Lesser Kestrels are opportunistic invertebrate feeders which mainly utilise available and most abundant prey species. Female birds are significantly heavier than males, but the latter maintain higher body fat reserves for the larger part of their stay in South Africa.