Beyond the blood: Diversity and Mortality Impact of Haemosporidian Parasites in European Birds.

Haemosporidians (protists) are widespread vector borne parasites that infect different vertebrate hosts, including humans and birds. Avian haemosporidians are globally distributed and classified in three main genera, Plasmodium, Haemoproteus and Leucocytozoon. They are of One Health, veterinary and economic importance, with spillovers between wildlife and livestock or non-native birds in zoos or aviaries. Their prevalence and diversity are usually estimated through the presence of gametocytes (erythrocytic stages) in blood smears and their molecular investigations (barcoding region in the mitochondrial cytochrome b gene), mainly in bird species that are caught by mist nests. However, this does not reflect the true prevalence and effect of these parasites, as many bird species are under-sampled and tissue stages, which can and do cause mortality, are under-studied. This project will understand the scale of mortality associated with infection status and spillover dynamics of haemosporidian parasites in European passerine and non-passerine birds. First, I will investigate a wide spectrum of bird species for the presence and diversity of the parasites and test mechanism of co-evolution with their hosts, using collected blood samples and tissue samples obtained from collaborators. Second, I will use the carcasses of common bird species dead from natural causes and collected by our collaborators to investigate the tissue stage development of the parasites, their prevalence, and effects on birds. These will result in a step change in our understanding of the epidemiological and pathological implications of avian haemosporidian infections, through the newly uncovered host-parasite interactions, and help conservation and management of bird populations.