Revista Chilena de Historia Natural 76 (3): 451-457, 2003
RESEARCH ARTICLE
Morphologic and behavioral development of white-throated hawk Buteo albigula
(Aves: Accipitridae) nestlings in northwestern Argentine Patagonia
The morphological and behavioral development of white-throated hawk (Buteo
albigula) nestlings was studied near San Carlos de Bariloche, in northwestern Argentine Patagonia. The study was mainly based
on the monitoring of two nestlings produced at different nests during 2001-2002 breeding season, and was reinforced with data
obtained at libitum in other nests the same and previous breeding seasons. The nestling period extended for approximately 6 weeks.
Morphological development was characterized by several changing features, but the most surprising was the development of first and
second natal down, which was only known, among Neotropical Buteo species, for B. brachyurus. Nestling
behavioral development matched the general patterns observed for Buteo spp. Of comparable body size. Besides, a
juvenile (dead accidentally) was characterized for the first time in Argentina, and two adults, banded near their nests, were measured
and weighed (first data for B. albigula). The juvenile was relatively similar to that described in Chile. The adults,
which would be the first white-throated hawks ever banded, add to the few specimens measured in the breeding range known for the
species.
Key words:
adult weight and
measurements, Buteo albigula, juvenile description, nestling development, white-throated hawk
