Parasites and Pathogens of Eastern Bluebirds (Sialia sialis): A Field Survey of a Population Nesting Within a Grass-Dominated Agricultural Habitat in Georgia, U.S.A., with a Review of Previous Records

The parasite community associated with a population of eastern bluebirds (Sialia sialis) nesting in a grass- dominated habitat in northern Georgia, U.S.A., was surveyed by live examination of adults and nestlings; examination of feces, nesting materials, and blood smears; necropsy; and polymerase chain reaction techniques. During the course of 5 breeding seasons, we found 10 macroparasite species, which included 1 tick species (Ixodes brunneus), 1 louse species (Philopterus sialii), 1 species of hematophagous mite (Dermanyssus prognephilus), and 5 other species not previously reported from eastern bluebirds, including an acanthocephalan (Plagiorhynchus cylindraceus), a species of strongyloid nematode, a cestode (Hymenolepis sp.), a nestling bird fly (Carnus floridensis), and a nest mite (Campephilocoptes sp.); a description of feather mites associated with the population was not included in this report. Overall prevalence of macroparasites was 16.1%. We also detected 5 species of protistan parasites, including Haemoproteus fallisi, Plasmodium relictum, Trypanosoma avium, and 2 others, an Atoxoplasma sp. and a Sarcocystis sp., which represent new host–parasite records. One bird tested positive for West Nile virus and for St. Louis encephalitis virus. More than 50% of the birds examined were infected with 1 or more microparasites. Prevalence of microparasites varied by examination method employed. An updated list of known parasites of eastern bluebirds gathered from published literature and database searches is provided.