Avian malaria and body conditioning in four species of songbirds

Abstract

Avian malaria is a common disease in songbirds, caused by protozoans in the genera Plasmodium, Haemoproteus, and Leucocytozoon. These parasites can negatively impact bird survival, reproductive success, and body condition. Four species of songbirds were sampled during the reproductive season; the American redstart, the gray catbird, the cedar waxwing, and the red-eyed vireo. The study aimed to determine parasite prevalence in these species, as well as to evaluate a relationship between infection and body condition. Results detected a high parasite prevalence using PCR (94%) but a much lower one using microscopy (37%), suggesting that parasite prevalence is high while parasitemia is low. Parasite infection did not seem to affect any measure of body condition. We found that within infected vireos, females had a higher H/L ratio than males, and that breeding waxwings had higher parasite prevalence and lower body condition than migrating birds, consistent with infection by Leucocytozoon.