Water depth selection during foraging and efficiency in prey capture by the egrets Casmerodius albus and Egretta thula (Aves, Ardeidae) in an urban lagoon in Rio de Janeiro State, Brazil


Autoria(s): Moreno,Aline B.; Lagos,Adriano R.; Alves,Maria Alice S.
Data(s)

01/03/2005

Resumo

This study aimed to evaluate the water depth selection during foraging, the efficiency in prey capture, and the food items captured by Casmerodius albus (Linnaeus, 1758) and Egretta thula (Molina, 1782). The work was conducted at an urban lagoon, Lagoa Rodrigo de Freitas, Rio de Janeiro. Four transects were made each month (two in the morning and two in the afternoon) for six months. When the birds were detected foraging, the water depth and the types of prey captured were recorded. There was no significant relationship between the foraging efficiencies of the two species. However, they differed in relation to the water depth when foraging, and also in the food items captured. Casmerodius albus captured mainly fishes while Egretta thula captured mainly invertebrates. The results suggest that the differences in water depth when foraging and the food items captured allow a differential use of the food resources available by C. albus and E. thula at Lagoa Rodrigo de Freitas.

Formato

text/html

Identificador

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212005000100016

Idioma(s)

en

Publicador

Fundação Zoobotânica do Rio Grande do Sul

Fonte

Iheringia. Série Zoologia v.95 n.1 2005

Palavras-Chave #Foraging depth #Casmerodius albus #Egretta thula #Lagoa Rodrigo de Freitas
Tipo

journal article