Abstract
<jats:p>Avian haemosporidian parasites (Haemosporida) are widespread among passerine birds. While long considered benign, detailed studies revealed severe consequences, including tissue/organ damage and mortality. Climate change exacerbates the spread of blood-sucking vectors of haemosporidian parasites from southern tropical regions into new northern regions. In our study, we focused on the diversity of three most prevalent haemosporidian parasite genera infecting birds in the White Sea region: Plasmodium, Haemoproteus, and Leucocytozoon. We found haemosporidian parasites in 60% of sampled passerine birds, with prevalent co-infections, necessitating further genetic analysis. Despite challenges and a small sample size, we identified unique parasite lineages underscoring the need for ongoing research. Additionally, we identified seven malaria genetic lineages in 11 birds from five species, with three lineages likely originating from tropical Africa. Our findings highlight the importance of monitoring haemosporidian parasites spread in northern avian populations, especially amid changing environmental conditions.</jats:p>