Factors associated with the geographic distribution of leucocytozoa parasitizing nestling eagle owls (Bubo bubo): a local spatial-scale analysis

Knowledge of the factors influencing the patterns and distribution of parasite infections and disease outbreaks is a major question in disease ecology and conservation research. In this study, we use a highly efficient PCR approach to detect blood parasites and investigate the factors influencing geographical variation in the distribution of leucocytozoids parasitizing nestling eagle owls (Bubo bubo) over a 3-year study period. We found that both prevalence and intensity of infections by the single lineage of Leucocytozoon ziemanni infecting nestling eagle owls in the study area increased with local owl population density and decreased with nest height above sea level. Overall, these results suggest that higher horizontal transmission rates under higher host density conditions together with the presence of adequate habitats for larval development of vectors are relevant factors influencing blood parasite distribution in the study system.This work received financial support from the projects: CGL2005-05611-C02-02/BOS (Ministerio de Educación y Ciencia), PAI05-053 (Junta de Comunidades de Castilla-La Mancha), and PCI08-0130-3954 (Junta de Comunidades de Castilla-La Mancha). During this work J.O. was supported by a post-doctoral JAE-Doc (CSIC) contract.Peer Reviewe