Hard tick infestation of birds of prey (Aves: Accipitriformes, Strigiformes, Falconiformes) in the Western Palearctic: New data and literature review

Tick infestation of songbirds has been extensively studied at global and regional scales but relevant data on birds of prey remain scarce and fragmentary. Raptors are of particular epidemiological relevance because their large size, wide-ranging movements and nesting habits may facilitate long-distance dispersal of ticks, and endophilic tick species (e.g. from prey animals) may even persist in their re-used nests. In this study, we aimed to compensate for the lack of comprehensive data in this context. First, more than 1800 birds of prey were examined at 61 sites in Central and South-Eastern Europe, encompassing both continental and Mediterranean climatic regions. Ticks (n = 839) were obtained from 98 birds representing 13 raptor species from three avian orders. Twelve tick species were identified, the most abundant being Rhipicephalus turanicus, Haemaphysalis concinna and Ixodes ricinus. Several previously unknown tick-host associations were revealed. Molecular-phylogenetic analysis showed that sequences of Ixodes arboricola from Tawny Owls (Strix aluco) clustered separately from other conspecific sequences, raising the possibility that Ixodes strigicola Schulze and Schlottke, 1929 is a valid species. Owls proved to be the most heavily tick-infested, particularly Eurasian Eagle-Owl (Bubo bubo) nestlings. Endophilic and rodent-associated tick species were significantly more common on owls and on bird species nesting in cavities or buildings, whereas diurnal raptors were predominantly infested by generalist and exophilic ticks. These patterns highlight the importance of nesting ecology and prey composition in shaping tick assemblages on raptors. The results provide novel insights into tick-raptor associations, contribute new records of tick species from birds of prey, and improve our understanding of the role of raptors in tick maintenance and dispersal which appears to be particularly important in the case of cavity-nesting species. In addition to field sampling, a comprehensive database from nearly 150 published sources revealed that 32 tick species have been reported from birds of prey in the Western Palearctic to date.