La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Food of the Cattle Egret (Bubulcus ibis) in South African grassland
Auteurs :	Grzegorz Kopij, Auteur
Type de document :	Article
Dans :	Vogelwarte (40(1-2) Oct., 1999)
Article en page(s) :	98-109
Langues:	Allemand
Résumé :	The study is based on stomach content and boli analyses originated from chicks and adult birds living in South African grassland. Bulk of the Cattle Egrets' diet consisted there of insects (69% of total dry mass), other arthropods constitute 2% and vertebrates 28%. Insect prey consisted mainly of Orthoptera (47%, mainly Acrididae) and Isoptera (12%, exclusively Hodotermes mossambicus). Coleoptera, Lepidoptera and Diptera constituted only a supplementary insect ingredient. In the diet of the chicks, a two-fold higher proportion of vertebrates and a lower proportion of insects was shown in comparison with the adult diet. In the same colony, during the 1976/1977 breeding season (with higher rainfall) the proportion of invertebrates and vertebrates was similar, while during the 1993/1994 breeding season (lower rainfall), the proportion of invertebrates was much higher than that of vertebrates. In summer (September-March) most of the adult diet consisted of insects, whereas in winter (June-August) it consisted mainly of vertebrates. The proportion of invertebrates increased and that of vertebrates decreased in the diet of chicks, as they grow.

Lundi , mardi et jeudi de 9h à 12h et de 13h à 17h00 : ouverture au public ...