Diet of chicks of Cattle Egrets Bubulcus ibis in the lower Soummam valley, Algeria

  • Rachida Gherbi-Salmi
  • Salaheddine Doumandji
  • Claire Voisin

Abstract

The diet of Cattle Egret chicks in the lower Soummam valley, Algeria, was investigated in 1998 and 2006, when 145 and 23 regurgitates were collected,  respectively. In 1998, 1 698 individual prey items were identified. Insects formed the bulk of the diet of chicks: 94% in terms of frequency, 71% in terms  of mass. Orthopterans were dominant, especially in terms of biomass (22% by frequency, 58% by mass), whilst Dipterans were well represented in numbers (59% by frequency). Vertebrates, despite their lesser frequency (3%), contributed 23% by mass of the diet. In 2006, 441 prey items were identified. The contribution of insects decreased to 79% by frequency and 15% by mass (mostly Orthopterans) but vertebrates made up a higher frequency: 20% of prey  items and 85% by mass of the diet. The availability of prey items was not correlated to their occurrence in the diet, suggesting that the Cattle Egret is a selective predator, with adults selecting prey species for their chicks. A drought in the spring of 2006 increased the availability of fish and lizards to the Cattle Egrets.

OSTRICH 2012, 83(2): 99–104

Author Biographies

Rachida Gherbi-Salmi
Laboratoire de Zoologie Appliquée et d’Ecophysiologie animale, Faculté des Sciences de la Nature et de la Vie, Université de Béjaïa, 06000 Béjaïa, Algeria
Salaheddine Doumandji
Département de Zoologie Agricole et Forestière, Institut National Agronomique, El Harrach, 16200 Alger, Algeria
Claire Voisin
Muséum National d’Histoire Naturelle, UMS 305, CP 305, 57 rue Cuvier, F-75005, Paris, France
Section
Articles

Journal Identifiers


eISSN: 1727-947X
print ISSN: 0030-6525