Habitat associations of the rufous-legged owl (Strix rufipes) in northern Andean Patagonia

F. BEAUDOIN, M. MERMOZ, A. TREJO Y V. OJEDA

Campos do Jordao, Brasil

Congreso; 25th International Ornithological Congress; 2010

International Ornithological Committee

The rufous-legged owl (Strix rufipes) is a medium-sized owl endemic to the Austral temperate forests of Argentina and Chile. It is classified as Vulnerable in these countries, where it is also considered of sanitary importance because its distribution overlaps that of the long-tailed rat (Oligoryzomys longicaudatus), reservoir of the Andes hantavirus causing an endemic disease in the local human population. Reports on diet indicate that rufous-legged owls are important predators of the rat. Despite being relevant for human health, little is known about their habitat associations and limitations. We conducted acoustic lure surveys of rufous-legged owls on stations placed every 1-km along roads in forested habitats in northern Andean Patagonia. Our objective was to determine if owls were associated with particular forest types and fragmentation scenarios. We detected owls at 289 of 424 (68%) stations. Preliminary analyses indicate that owls were significantly more abundant in wild and rural forest landscapes than in urban and suburban forested areas and in low forests or scrubland compared to tall forests (either conifer or broadleaved). The latter was surprising since this species was considered as dependent on oldgrowth tall forest, similar to S. oxidentalis from the Northern Hemisphere. Currently, we conduct research at smaller scales, such as habitat use of territorial pairs, which will help explain the occupancy patterns found at landscape scales.