Parasite Prevalence in Dark-eyed Juncos, Junco hyemalis, Breeding at Different Elevations

Abstract

During the summer of 2001, Dark-eyed Juncos (Junco hyemalis) were captured within the lowest (1000 m above sea level) and highest (2000 m asl) elevation extremes of their breeding range in Jasper National Park, Alberta. Blood samples were taken to identify parasite genera, and to test for differences in parasite prevalence among elevations. The most common parasites at either elevation were Haemoproteus spp., Leucocytozoon spp., and Trypanosoma spp. A significantly higher proportion of low- compared to high-elevation birds was infected by at least one of these, supporting the prediction that high-elevation habitats may be refuges from parasites.