Blood parasites in birds from Madagascar.

Madagascar has long been recognized for its unique and diverse biota. In particular, significant effort has been made to establish baseline population data to better conserve the endemic avifauna. During field expeditions between 1993 and 2004, birds were mist-netted at 11 different sites, at elevations from 60 m to 2,050 m above sea level. Data on endemic status, forest type, and habitat preference were recorded. Thin blood films from 947 birds, belonging to 26 families and 64 species, were examined by light microscopy to determine the prevalence of blood parasites. Of these 947 birds, 30.7% were infected by at least one species of blood parasite, 26.8% of which were infected by more than one species. Species of Haemoproteus were the most prevalent (17.4%), followed by microfilariae (11.0%), Leucocytozoon spp. (9.4%), Plasmodium spp. (1.9%), Trypanosoma spp. (0.9%), and Babesia spp. (0.2%). Species level identifications confirmed the presence of 47 species of hemosporidians and trypanosomes, which is notably high and mirrors the diversity of their avian hosts. Eleven (23.4%) of these parasite species were new to science and thought to be endemic to the island. Significant differences in prevalence were observed by sample site, forest type (humid vs. dry), and habitat preference. Birds from all elevational zones sampled were infected, although not all parasite genera were present in each zone. Four of the six endemic avian families or subfamilies (Bernieridae, Brachypteraciidae, Philepittinae [Eurylaimidae], and Vangidae) were sampled and found to be parasitized. Of the families with the largest sample sizes, the Zosteropidae and Ploceidae had the highest prevalence of infection (65.6% and 49.3%, respectively). The vectors of hematozoan parasites in Madagascar are currently unknown. These results add to the current knowledge of avian parasitism in Madagascar and are of particular interest for the conservation of endemic species, as well as threatened or endangered populations.