Avian haemosporidian prevalence and its relationship to host traits in Western Tennessee

Abstract

Avian malaria and related haemosporidian parasites (genera Plasmodium and Parahaemoproteus) are the most common parasites in many bird populations and are known to affect survival and reproduction. We analyze how species-level and individual-level traits influence parasite prevalence among species and infection status among individuals. We collected blood samples of 625 individuals from 35 host species and used PCR to screen for infection status. We found that 44% of the individuals were infected, and 38 unique lineages of haemosporidian parasites were obtained. Total prevalence and prevalence of Plasmodium and Parahaemoproteus separately were significantly heterogeneous across species, ranging from 0 to 100%. Total and Plasmodium prevalence increased significantly with host species abundance, but Parahaemoproteus prevalence did not. Parasite prevalence did not vary with other species-level traits, including species mass, annual survival, nest type, nesting or foraging height, and degree of sexual dimorphism. Individual-level traits, such as age and sex, did not predict infection status of individuals. Our research documents a high diversity of haemosporidian parasites and substantial variation in parasite prevalence across host species. However, contrary to expectations, haemosporidian prevalence is not strongly related to many host life history traits. Future studies that examine vector abundance and parasite prevalence across habitat types might be especially productive.