Distribution and breeding performance of a high-density Eagle Owl Bubo bubo population in southeast Spain

摘要

Capsule Despite very high breeding density, no density-dependent effects on reproductive parameters were detected. Aims To describe the distribution, abundance and breeding performance of Eagle Owls and to analyse density-dependent effects on breeding parameters. Methods We censused a high-density population of Eagle Owls in southeast Spain between 2003 and 2010. To census the population we employed acoustic signals and searched for field signs. Breeding performance was determined by nest monitoring. Results The population's density, productivity and fledgling rate were the highest recorded for this species. We detected a negative relationship between the laying date and productivity. Despite breeding pairs' high density, no density-dependent effects on reproductive parameters were detected. Conclusions Our results suggest that resources in the study area (mainly the availability of Rabbits Oryctolagus cuniculus) and adult turnover might be responsible for this population's high density and breeding success.