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Show 73 college of science Behavioral defenses, such as preening in pigeons, can be an effective defense against ectoparasites. However, other defenses against ectoparasites include immune defenses, which can create specific an-tibodies against ectoparasites. In the system we study, an ectoparasitic fly, Pseudolynchia canariensis, transmits the malaria blood parasite Haemoproteus columbae between pigeons. With this experiment, we tested whether pigeon preening or pigeon immune defense work independently or together to decrease fitness of the fly and/or of the malaria parasite they carry. There were four treatments in this experiment: pigeons that had no defenses against the fly, pigeons that had immune defenses only, pigeons that had preening defenses only, and pigeons that had both defenses. At the start of the ex-periment, ten malaria-infected flies were added to each bird. Both defenses were effective in reducing fly fitness. Blood samples were collected from all birds every three days to determine malaria prevalence and to directly count the malaria parasites in the blood to determine infection intensity by examining stained blood smears under a microscope. To understand the dynamics of malaria infection the number of immature and mature malaria parasites per field was quantified. We also looked at the onset of infec-tion, peak infection intensity, and total parasites seen in the blood for the duration of the experiment, which was carried out for 70 days after malaria flies were added. These data are now being analyzed to answer our final question: did the reduced fitness of the flies impact the number of malaria para-sites transmitted to the pigeons? We expect that birds with both immune and behavioral defenses will have the lowest prevalence of malaria parasites and later onset of malaria if fewer fly bites decrease malaria transmission. We also expect birds with neither of these defenses to have the highest preva-lence and most rapid onset. Birds with one defense are hypothesized to have a lower prevalence and later onset than those without any defenses, but will have higher prevalence and sooner onset than birds with both immune and behavioral defenses. THE EFFECT OF HOST DEFENSE ON A VECTOR AND THE PARASITE IT CARRIES Autumn Henry (Dale Clayton, Sarah Bush) Department of Biology University of Utah UNDERGRADUATE RESEARCH ABSTRACTS Autumn Henry Dale Clayton |
