Biologia reprodutiva de Ardeidae em três ninhais do Rio Grande do Sul, Brasil

Abstract

The family Ardeidae frequently breeds in mixed colonies forming dense heronries. The present study aimed at verifying the breeding biology of four species in this family in three

heronries of Rio Grande do Sul states during the years 2004 to 2009 through diary spot observations. Altogether, were registered 1403 nests and 4009 eggs distributed among species Nycticorax nycticorax, Bubulcus ibis, Ardea alba and Egretta thula. The species with the largest number of nests and eggs in all heronries was Bubulcus ibis, considering that in

Triunfo it differed in number of nestlings along the years (P = 0.001). As for the heronry of Porto Alegre, A. alba differed significantly between the number of eggs (P = 0.02) and

nestlings (P = 0.006) during the years. In Lindolfo Collor, the analysis of variance showed that there was no significant difference in the number of eggs and nestlings along the years (P > 0.05). Also, there wasn´t any significant difference in the number of eggs and nestlings for any species (P > 0.0