Blood Parasites in Birds From Madagascar

Abstract

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.

Microscopic and molecular characterization ofHepatozoon domerguei(Apicomplexa) andFoleyella furcata(Nematoda) in wild endemic reptiles from Madagascar

“…Although this practice is currently easy to apply, and despite the wide range of parasites that can be found in reptile blood samples [28], studies using this approach to assess parasite prevalence and diversity are still generally lacking. Parasite research in Madagascan amphibian and reptile hosts has mainly focused on a few groups, such as the malarial parasite Plasmodium [71], monogenean polystomatids [11, 66], nematodes [35, 42], or it has been focused on well-known conservation threats such as the amphibian chytrid fungus Batrachochytrium dendrobatidis Longcore et al, 1999 [16, 19, 86, 87], while other groups remain less studied.…”

Timing and Number of Colonizations but Not Diversification Rates Affect Diversity Patterns in Hemosporidian Lineages on a Remote Oceanic Archipelago

“…Valkiūnas (2005) summarized prevalence data for Plasmodium and Leucocytozoon, showing that Leucocytozoon is globally more prevalent than Plasmodium. The relative prevalences of the two genera in the continental biogeographic zones closest to the Mascarenes are quite similar, but those of Leucocytozoon are usually slightly higher: 1.9% and 9.4% in Madagascar, 3.2% and 4.6% in the Ethiopian region, and 0.8% and 2.9% in Southeast Asia for Plasmodium and Leucocytozoon, respectively (Valkiūnas 2005;Savage et al 2009). Data on the prevalence of hemosporidians in southern Africa, another potential source of parasites for the Mascarenes, are currently lacking, and such data will help in further assessments of the effect of prevalence on immigration dynamics of hemosporidians.…”

“…If so, the higher number of colonizations by Leucocytozoon relative to Plasmodium, which contradicts our initial hypothesis of a higher immigration rate for Plasmodium, might reflect a greater continental diversity of Leucocytozoon rather than differences in their dispersal biology. While appropriate data are currently lacking to evaluate this hypothesis, Savage et al (2009), in a detailed morphological survey of avian hemosporidian blood parasites in Madagascar (the source pool nearest to the Mascarenes), reported a large difference in diversity between Leucocytozoon (15 species, of which five were considered endemic to Madagascar) and Plasmodium (five species, of which one was considered endemic to Madagascar).…”

Avian malaria on Madagascar: bird hosts and putative vector mosquitoes of different Plasmodium lineages

“…Either blood samples were examined microscopically [11, 12] or just a small number was analyzed by PCR [13]. So far, data about vectors in Madagascar transmitting avian malaria parasites are lacking.…”