INVESTIGADORES
OJEDA valeria Susana
congresos y reuniones científicas
Título:
Hollow-using birds in the Austral Temperate forests of Patagonia
Autor/es:
OJEDA, V, M. L. CHAZARRETA Y S. DÍAZ
Lugar:
Campos do Joardao, Brasil
Reunión:
Simposio; 25th International Ornithological Congress; 2010
Institución organizadora:
International Ornithological Committee
Resumen:
Inventories of hollow-using fauna as well as research on what constitutes a potential nest tree have been conducted for the last decades in the Northern Hemisphere and Australia. Contrarily, in Neotropical forests, only incipient research has been conducted on the hollow resource and the hollow-users. We examined the composition and general habits of the avifauna that use hollows in the Austral Temperate forests of northern Andean Patagonia. We assembled data from both literature sources and field observations, starting in 1998. We present a species list, the types of cavities used (woodpecker or natural origin), features of the hole nesting sites (typical height, depth, location on trunk or branch, etc.) and alternative sites known for some hollow-using species. Among other findings, we listed two previously unknown cavity-users, one of which behaved like open nester or cavity nester depending on the environmental conditions. Cavities excavated by different woodpecker species were used by different secondary users, according to body size. Magellanic woodpecker (Campephilus magellanicus) cavities were used by the Austral parakeet (Enicognathus ferrugineus) in a much higher proportion in young lenga (Nothofagus pumilio) stands than in mature lenga stands, due to a differential availability of natural holes. Last, we found that about half of the Patagonian forest birds are hollow-users, which is a high proportion compared to most other forests worldwide. The selection pressures that probably gave rise to a widespread hollow use among the Austral Temperate birds are probably related to the low temperatures that can occur year-round.