Parasitic skin mites associated with wild birds are understudied members of host–parasite systems in Europe despite their ecological importance, potential role as disease vectors, and effects on host fitness. Using a multidisciplinary approach combining faunistic, ecological, and molecular methods, this study investigated two mite species that parasitize passerine birds in Hungary, Harpirhynchus dusbabeki and Blankaartia acuscutellaris. Birds were examined during field sampling conducted between 2022 and 2024 at bird ringing stations and through a nationwide volunteer bird-ringing network. Parasites were identified morphologically, prevalence patterns were analyzed statistically, and mitochondrial genetic data were used to assess phylogenetic relationships. The occurrence of H dusbabeki was recorded in Hungary for the first time, and its host spectrum was found to extend to multiple host species beyond its previously known primary host, the Bearded Reedling. Blankaartia acuscutellaris infested several passerine species, with a significantly elevated prevalence in Bearded Reedlings and markedly higher prevalence among juveniles. Genetic analyses revealed close relatedness between the Hungarian and Slovakian populations of B. acuscutellaris, but showed distinct genetic separation from morphologically identified conspecifics from Laos, Asia. These findings improve the understanding of mite–passerine associations in Central–Eastern Europe and highlight the value of integrating ecological and molecular approaches to reveal the patterns of host exploitation and geographic differentiation in parasitic mites.

Host life history traits (e.g., migratory strategy) are important factors that influence host-parasite systems, yet empirical evidence remains inconsistent, particularly in birds of prey. We investigated the prevalence and diversity of avian haemosporidian parasites, Plasmodium spp. and Haemoproteus spp., in a long-distance migratory raptor, the Red-footed Falcon (Falco vespertinus) (n = 139), and compared them with those in sympatric, largely sedentary Common Kestrels (Falco tinnunculus) (n = 468) and Eurasian Jackdaws (Coloeus monedula) (n = 40). Samples collected from shared breeding colonies and pre-migratory roosts in Hungary were screened by PCR targeting haemoparasite mitochondrial DNA. We provide the first evidence of haemosporidian infections in Red-footed Falcons, revealing a markedly low prevalence and limited lineage diversity, with infections restricted to a single Haemoproteus lineage (FALAMU02) in roosting birds and one generalist Plasmodium lineage (SGS1) in a nestling. In contrast, Common Kestrels exhibited higher prevalence and substantially greater haemoparasite diversity, while infections of Eurasian Jackdaws were confined to a single brood. Notably, no Haemoproteus infections were detected in Red-footed Falcon nestlings. These findings reveal contrasting parasite prevalence and lineage diversity among the three host species, with the age-associated increase in infection suggesting that parasite detectability and/or cumulative exposure may contribute to these patterns. The contrasting migratory strategies of the two falcons may represent an ecological trait contributing to these differences, although this hypothesis requires further testing. Overall, our results provide the first evidence of haemosporidian infections in Red-footed Falcons and highlight the importance of host ecology, age, and migratory strategy as potential factors shaping haemosporidian assemblages in raptors.