Host Specificity and Distribution of Avian Blood Parasites

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0089226. Ricklefs.The proposed research uses molecular and genetic techniques (DNA sequencing and PCR-based RFLP assays) to characterize the distribution of blood parasites (Plasmodium and Haemoproteus) in species of birds on islands in the Lesser Antilles. Isolated island populations of birds and other animals are vulnerable to infection by introduced pathogens, which may influence population size and the habitat distribution of their hosts. Indeed, the extinction of a number of endemic species of birds in the Hawaiian Islands has been attributed to the introduction of malaria and pox viruses. The extent to which exotic host species can influence native species, and the composition of local communities, in part depends on the likelihood of host-switching. Although host-switching has been examined in the medical literature for some diseases, it has not been addressed from a community perspective across a broad region, such as the Caribbean. This project builds on massive collections of blood smears and buffered blood samples obtained from almost 2,000 birds representing 37 species, and the complete phylogenetic appraisals of island populations of each avian host species. Research will correlate community relationships and geographic distributions of both host and parasite in a contemporaneous fashion. Fieldwork will substantially increase the sampling of host individuals in the West Indies to determine seasonal, habitat, and annual variation in parasite infections. Laboratory determination of parasite gene sequences will allow an accurate description of host- and parasite-sharing within island communities of Antillean birds. In addition, it will facilitate an understanding of patterns of colonization and endemism in a regional parasite fauna, as well as a quantification of the association between phylogenetic patterns in hosts and parasites. This history may reveal generalizations about potential emerging diseases in wildlife species.