Comportamiento de alimentación del Fio-fío Silbón (Elaenia albiceps chilensis) en bosques de la patagonia.

CHUST, L; CUETO VR; GUERRA NAVARRO, C; BRAVO S. P.

ORNITOLOGIA NEOTROPICAL

NEOTROPICAL ORNITHOLOGICAL SOC

Lugar: ALEMANIA; Año: 2012 vol. 23 p. 313 - 323

1075-4377

Foraging behavior and microhabitat selection of the White-crested Elaenia (Elaenia albiceps chilensis) in Patagonia forests. ? The study of foraging behavior is useful to understand how birds use the environment and what factors play an important role in habitat selection. We evaluated the maneuvers used to capture prey and the selection of foraging microhabitat by the White-crested Elaenia (Elaenia albiceps chilensis), a very abundant migratory bird in Patagonian forests during spring and summer. Behavioral observations were made in mixed forests of Cohiue (Nothofagus dombeyi) and Cypress (Austrocedrus chilensis). We compared patterns between forests that experienced tree extraction of the first species to others in which no human alterations took place. In both forests conditions, White-crested Elaenias mainly used sally-hovering to capture prey and to a lesser extent glean and sally-strike. The most commonly used substrate for prey capture was the foliage. The foraging microhabitat selected in both sites was the canopy, and Coihue trees. The rest of the vegetation profile and other species of trees and shrubs were used less than expected by chance. It is thought that birds that capture their prey by hovering are not constrained by the structure of the vegetation; however, White-crested Elaenias selected specific foraging microhabitats, suggesting that other environmental variables, such as differences in food supply, could drive the foraging behavior of this species. Coihue trees extraction in the past did not change the foraging behavior of White-crested Elaenias, and it could be negative for populations that eventually face alteration of native evergreen forests of Patagonia.