Prevalence and diversity of haemosporidians in a migratory high-elevation hummingbird in North America.

Hummingbirds (Trochilidae) are sensitive to environmental changes because of their extraordinary ecology, metabolism, and the highest red blood cell counts found in any vertebrate. These physiological attributes may render hummingbirds particularly susceptible to the effects of haemosporidian (blood parasite) infections. Much of the research on haemosporidians in hummingbirds has been conducted in South America; less is known about haemosporidian diversity and prevalence in North America. We sought to determine the prevalence and diversity of haemosporidians in a high-elevation species, the Broad-tailed Hummingbird (Selasphorus platycercus). Blood samples (N = 314) from 25 sites in Colorado and Wyoming were screened for haemosporidians using microscopy (n = 311) and PCR (n = 301). Both microscopy and sequencing diagnostic techniques detected haemosporidians in the same 5 hummingbirds, with an overall prevalence of 1.59%. Positive samples were sequenced at the cytochrome b gene and identified Haemoproteus archilochus and two Haemoproteus sp. not previously detected in North America. No parasites of the genera Plasmodium or Leucocytozoon were detected. Our study provides the first report of the prevalence and diversity of haemosporidians in Broad-tailed Hummingbirds in the Rocky Mountains.