First Records of Feather Mites and Haemosporidian Parasites in the Isabelline Wheatear (Oenanthe isabellina) from the Westernmost Part of the Species Breeding Range

Host range expansions are an important factor for shaping the community of associated symbiotic organisms. Birds, as a highly mobile group of animals, are of particular interest to study with respect to the diversity and the distribution of the organisms using them as hosts during such large-scale movements. The Isabelline wheatear (Oenanthe isabellina ) is a species with a main breeding area in Asia, which has expanded west, towards the Balkans, since the middle of the last century. We collected feather mites and blood samples for haemosporidian parasites screening from adult and juvenile Isabelline wheatears from the westernmost edge of the species breeding area in western Bulgaria. The feather mite species Alaudicola rosickyi (Černy, 1963), previously found on other wheatear species, was found for the first time on Isabelline wheatears. One species of avian malaria parasites—Plasmodium relictum (Grassi and Feletti, 1891) (lineage SGS1)—represented the first record of a malaria parasite in this host species in Europe. Increasing the sampling in the South European populations of the species will shed light on blood parasite species diversity and will reveal if other feather mite species have followed their host during its breeding range expansion.