TDK conference 2023

The primary aim of this work was to extend the scope of previous studies on bird ticks in Hungary, i.e., to include aquatic (water-associated) bird species, especially taking into account that these birds are usually long-distance migrants.

Between March 2021 and August 2023, 904 ixodid ticks were collected from 350 birds representing 40 species. These ticks belonged to seven species: Ixodes ricinus (n=447), Ixodes frontalis (n=31), Ixodes festai (n=2), Ixodes arboricola (n=36), Ixodes lividus (n=4), Haemaphysalis concinna (n=382), Dermacentor reticulatus (n=2). Nymphs of I. ricinus occurred with a single activity peak around March-May, whereas its larvae typically infested birds in May, June or July. By contrast, H. concinna usually had its activity maximum during the summer (nymphs in June-July, larvae later in July-August). Interestingly, two ornithophilic species, I. frontalis and I. arboricola were most active around winter months (between October and April). Importantly, significantly lower ratio of aquatic birds were found tick-infested, than songbirds. Several new tick-host associations were revealed, including I. ricinus from Greylag Goose (Anser anser), D. reticulatus from Great Egret (Ardea alba) and Sedge Warbler (Acrocephalus schoenobaenus). Ticks were collected for the first time in Europe from two species of predatory birds, as well as from Little Bittern (Ixobrychus minutus). Bird species typically inhabiting reedbeds were most frequently infested with H. concinna, and most ticks localized at their throat, as opposed to forest-dwelling avian hosts, on which I. ricinus predominated and ticks were more evenly distributed between the skin around eyes, the corner of beaks and the throat. The only I. apronophorus collected from Sedge Warbler in Lithuania showed sequence identity with conspecific ticks reported previously from Russia (Western Siberia).

In conclusion, aquatic birds appear to be less important in tick dispersal than songbirds. However, newly revealed tick-host associations in this category attest their hitherto neglected contribution. The results suggest that the habitat type will have significant impact not only on the species composition but also on the location of tick burden on birds. Migratory connection and gene flow between bird populations in Siberia and Central Europe were also confirmed by our data.