Avian haemosporidian prevalence and its relationship to host life histories in eastern Tennessee

Haemosporidian parasites (genera Plasmodium and Haemoproteus) are common blood parasites of birds transmitted by dipteran insect vectors. We analyzed blood samples from 329 individuals of 43 bird species in eastern Tennessee to better understand the relationship between the local community of birds and their blood parasites, including the distribution of parasites across hosts and the underlying ecological factors and life -history traits that influence parasite prevalence across host species. Using molecular methods, we found 144 individuals of 25 species to be infected with haemosporidian parasites (overall prevalence of 44 %). We distinguished 22 genetic lineages, including 11 in the genus Haemoproteus and 11 in Plasmodium. Fourteen percent of infected individuals harbored more than one parasite lineage. Across species, total prevalence increased with local abundance and decreased with incubation period, but did not vary with nesting or foraging height, average annual survival of host species, migratory or flocking behavior, sexual dimorphism, average species mass, or among sites. The prevalence of Haemoproteus was higher in species that nest 1-5 m above ground than in species that nest below 1 m or above 5 m, and the prevalence of Plasmodium was marginally higher in species with open-cup nests. Infection status did not vary with age, sex, or body condition. Our research reveals substantial variation in prevalence and richness of haemosporidian parasites, some of which is related to specific avian life history traits.