Dispersal and causes of mortality of the Barn Owl (Tyto alba) in Spain

Published:

Volume 42(1), June 1995. Pages 29-37.

Language:

English

Keywords:

Barn owl, dispersal, mortality causes, seasonal pattern of mortality, Tyto alba.

Abstract:

We have analysed the recoveries of barn owls fledged in Spain, in order to investigate the dispersal patterns and the causes of mortality of this species. Among birds ringed in Spain, the recovery distance was greater for birds ringed as nestlings than for adults. However, all nestlings that are recovered after more than one year were found within a radius of 50 km from the ringing place. This suggests that fledglings that dispersed long distances performed less well in later life. Like in other studies, no preferred direction of recoveries has been found. The main cause of mortality found in the study is shooting, both for adults and first year birds. The second most important cause of mortality is road casualties, which is usually the first cause in other European countries.