The food of Black-crowned Night Heron (Nycticorax nycticorax) nestlings in Extremadura (W Spain)

Full article

Published:

Volume 38(2), December 1991. Pages 277-287.

Language:

Spanish

Original title:

La alimentación de los pollos de Martinete (Nycticorax nycticorax) en Extremadura

Keywords:

Black Crowned Night Heron, nestling food.

Abstract:

266 nourishing bolus of Black Crowned Night Heron nestlings have been analyzed in Extremadura. In the composition of their diet, fish is the most frequent group (93,67 %), the presence of Barbus comiza being outstanding with 76,3 % in relation to the total percentage. The food of young herons in Extremadura differs from other localities in which comsumption of amphibia is more marked. This small comsumption of amphibia is possibly due to their absence in the Guadiana river, due in turn to the fact that they have been decimated by different species of introduced fish. Adult birds in the breeding season also hunts in daylight by capturing smaller prey then they usually consume. This fact may be due to the intention to supply the nestlings with food items of an adequate size. The size of prey consumed by chicks increase with advancing age.