Aspects of the ecology of the Barn Owl Tyto alba breeding in a Mediterranean area

摘要

Barn Owls Tyto alba occur on farmland throughout Europe (Taylor 1994), depending on the availability of nest-sites (e.g. cavities in cliffs, trees and old buildings) as well as on the abundance of small mammals (De Bruijn 1994). Breeding populations have decreased since new agricultural practices have reduced prey availability and nest-sites in old rural buildings (Ramsden 1998, Toms et al. 2001). Although Barn Owls frequently take birds, bats and insects as alternative prey (Taylor 1994), rodents and shrews represent the bulk of the diet in all habitats studied (Marti 1988, Taylor 1994). Barn Owl breeding density has been studied in different areas of central Europe (De Bruijn 1994, Poprack 1996) and population levels were correlated with cyclic fluctuations of small mammals (De Bruijn 1994, Taylor 1994). Data on breeding success have mainly relied on monitoring nestboxes (De Bruijn 1994, Taylor 1994, Poprack 1996). Diet has been extensively studied throughout Europe but prey other than mammals are often ignored (Taylor 1994). The biology of the Barn Owl is poorly known in the Mediterranean (Martinez & Lopez 1999)and no detailed accounts are available on Barn Owl ecology in urban areas. We provide data on breeding density, nest-sites, breeding success and diet in Rome (41 deg 53 min N, 12 deg 28 min E), central Italy.