ABSTRACT
The Great Horned Owl Bubo virginianus (Gmelin, 1788) has a wide distribution through Americas, from Canada and Alaska to Argentina and Uruguay. Beside common, several aspects of its natural history are still poorly known, especially at Neotropical Region. The aim of this study was to obtain data regarding to the home range, nesting and feeding habits of Bubo virginianus in the Brazilian Pampas. This study was conducted from April 2015 to April 2018, in Santa Margarida do Sul, central region of Rio Grande do Sul State, southern Brazil. The study area presents patches of Eucaliptus spp. tree, under which the vegetation is composed by grass with some spine bushes. The surrounding area of the main patch of Eucaliptus is used for extensive cattle ranch and rice and soy crops. Data was collected by direct observation, with unless one visit each 15 days during the non-reproductive period, and unless one visit per week during the breeding season. In these observations we checked the use of the nest and the use of diurnal resting perches, where we collected pellets for diet analyses. Considering 95% of locations, the home range of the pair of great horned owl was estimated as 0.35 km² considering MCP method or 0.41 km² considering Kernel estimates. Individuals seem interested in bordering locations of the home range during night and the center of the area for resting during the daylight. The nest was used for a period of three months, in three consecutive breeding seasons. Breeding season is related to the austral winter, with one or two chicks hatching near late winter. The juveniles stayed with the parents for up to 10 months (7 to 10 months) and dispersed from the parents’ home range in the autumn of the next year. Furthermore, diet was based in rodents, especially Holochilus vulpinus (Brants, 1827), and birds, following a common pattern for this species.
KEYWORDS
Grasslands; feeding habits; owls; reproduction; spatial ecology
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