Differences in haemoparasite assemblages of a migratory and sedentary falcon species: first molecular evidence of haemosporidia in Red-footed Falcons (Falco vespertinus)

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.