Intestinal and liver flukes of birds of prey (Accipitriformes, Falconiformes, Strigiformes) from Slovakia: uniform or diverse compound?

During 2012-2014 up to 286 birds of the orders Falconiformes (5 species), Accipitriformes (11 species), and Strigiformes (7 species) were examined for trematodes and this represents the first detailed study in Slovakia. A total of 12 trematode species belonging to the families Diplostomidae, Cyathocotylidae, Strigeidae, and Opisthorchiidae were identified. Rare infections were found in falcons where only two species (40 %) and three of 85 examined birds (3.5 %) were infected with a low range of two to four worms of generalists Strigea falconis or Plagiorchis elegans. Contrary to that, ten accipitriformes species (90.9 %) and 63 of 156 bird individuals (40.4 %) were infected with nine flukes: Conodiplostomum perlatum, Conodiplostomum spathula, Neodiplostomum attenuatum, Neodiplostomum spathoides, Parastrigea flexilis, Strigea falconis, Strigea vandenbrokae, Paracoenogonimus ovatus, and Metorchis bilis. S. falconis and N. attenuatum were the most frequent, occurring in parallel in eight and four bird species, in numbers up to 575 and 224. The intensity of infection with other fluke species was low ranging from one to 13 worms. Three owl (Strigiformes) representatives (42.9 %) were exclusive hosts for Neodiplostomum canaliculatum and Strigea strigis, and the proportion of positive and dissected individual birds was 10:45 (22.2 %). Both trematodes occurred in two or three owl species. In conclusion, apparent dissimilarity of trematode load of three unrelated lines of falcons, eagles, and owls was revealed. The present study extends our knowledge on the composition of the trematode fauna in Slovakia as all species except S. falconis and P. elegans that represent new host and species records in Slovakia.