Meeting Abstract

P3.30  Jan. 6  Variation in avian blood parasite prevalence, insect vectors and haematology associated with the recent colonization of a city FOKIDIS, H.B*; DEVICHE, P.; Arizona State University; Arizona State University Bobby.Fokidis@asu.edu

Urbanization negatively impacts many avian species, but some species survive and prosper in these novel habitats. One factor contributing to the success of these species in urban environments may be the lessened presence of parasite-transmitting vectors in urban than rural areas (a component of the “enemy-release hypothesis). An alternate explanation for such differences may be variability in the innate immune response to infection, resulting from differences in exposure to “stressful” stimuli associated with urban living. We examined patterns of hemoparasite prevalence, biting insect occurrence, granulocyte and mononuclear white blood cells (WBC) distributions in sedentary songbirds (four native and one introduced species) that vary in their tolerance to urbanization. These birds were found to host three types of hemoparasites (Trypanosoma sp., Haemoproteus sp., and Microfilariae). The prevalence of the two former parasite types varied at a microgeographic scale, across species, and across seasons. For three native species, heterophil, lymphocyte, and eosinophil WBCs varied between urban and rural sites. Urban collection sites showed a decreased abundance of both biting midges (Ceratopogonidae) and mosquitoes (Culicidae), which may account for differences in the occurrence of parasites between habitats. Explanations for observed patterns will be discussed in the context of consequences of city colonization by native wildlife.