The Curacao Barn Owl: Status and Diet, 1987-1989

We examined the status and diet of the Barn Owl, Tyto alba Scopoli, on the dry, southern Caribbean island of Curacao. Thorough surveys of natural (limestone plateau escarpments, caves, seaboard cliffs) and anthropogenic habitats (ruins, wells, attics) during 1987 and 1989, yielded 42 confirmed active Barn Owl sites (15 nest sites, 16 pair roosts, 11 other roosts of regular use). The total estimated population (1987-1989) was about 75 adult birds (31 pairs and additional individual birds). Breeding and daytime roost sites were predominantly located in fissures, cavities, and ledges along the escarpments of limestone pla- teaus; even though the species was also documented in two caves, a seaboard limestone cliff slope, and a few anthropogenic sites. It appears that nesting at caves and old plantation homes has greatly declined due to intensified disturbance. During the dry year of 1987, laying took place in the rainy season (October- December). In response to extended end-of-year rains in 1988, several sites achieved two broods in 1989. The main prey during both survey periods were introduced rodents, yet major differences in the importance of specific prey categories were evident. The results also indicate a high abundance of birds in the diet, as well as a high spatial and temporal variability in food composition.