| I studied the distribution, food and habitat selection, and conflict with fish farmers of the endangered Tawny Fish Owls (Ketupa flavipes) in Taiwan, from July 1993 to August 1996, to gain knowledge about their natural history for use in conservation of this species. Owls were associated with riparian original forest cover, close to coastal areas and occurring at low elevations, on the east side of the island. Foraging mainly occurred along streams, while use of creeks and fish farms increased as water levels rose. Owls commonly foraged along low-gradient riffles. Roost sites tended to be located in original riparian forests; the birds roosted at higher elevations in the summer and early fall seasons.; Owls moved more frequently during winter and while breeding. The length of two owl territories which included fish farms on the Nanshih Stream appeared to be shorter (5.7 and 6.7 km) than a territory (8.5 km) on Sakatang Stream, without fish farms.; Aquatic animals accounted for most of the owl's diet; however, I found regional and seasonal variations in diet composition. Larger or slow prey items like the Taiwan common toad (Bufo bufo gargarizans) and freshwater crabs (Candidioptamon sp.) were common prey items. Toad-eviscerating behavior occurred most often during April-June, probably due to the owlet's poor resistance to toxins found in the toads.; The rate of owl visitations to fish farms increased in cold months and during the owl breeding season, perhaps reflecting scarce prey abundance or higher energy needs. Owls tended to select fish of 101-600 g in mass at fish farms. |
