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dc.contributor.authorSpivey, Timothy J.
dc.descriptionThesis (M.S.) University of Alaska Fairbanks, 2017en_US
dc.description.abstractMallards (Anas platyrhynchos), the most abundant species of dabbling duck in North America, are increasingly wintering in urban centers at latitudes north of their traditional wintering grounds. We captured mallards throughout the non-breeding period in Fairbanks, Alaska in 2012/13 and 2013/14, as well as in Anchorage, Alaska, in 2014/15, to assess seasonal patterns in forage selection and body condition, as well as the influenza A virus (IAV) dynamics within these urban wintering mallard populations. Using stable isotope data (δ13C and δ15N values) from serum and whole blood, we identified seasonal shifts in diet from invertebrates and aquatic vegetation in autumn to anthropogenic food subsidies (i.e. corn and bread) during winter by mallards in both populations. Additionally, mallards wintering in Fairbanks maintained higher body mass levels throughout the winter period than mallards wintering in Anchorage, which declined in mass from autumn to late winter. To study the associated health conditions mallards wintering at these high-latitude locations experience, we examined infection dynamics of influenza A viruses (IAVs), as mallards are considered a natural reservoir host of IAV viruses. We screened mallards for both active infections and prior exposure to IAVs. Molecular screening indicated both IAV prevalence and seroprevalence varied by each season at each site/year. Age differences were pronounced for both infection and immune responses, with juvenile mallards having higher IAV prevalence and adults having higher IAV seroprevalence. Evidence for active infections and antibodies to IAVs were detected throughout each sampling year at both locations. Variability in mallard immune responses, suggests individual heterogeneity in the timing of infections and duration of immune responses to IAVs across the non-breeding period. Thus, the combination of these findings provide valuable information about when mallards may be relying most on anthropogenic food subsidies and the potential for these populations to serve as biotic reservoirs for IAVs throughout the non-breeding period. Wildlife management agencies may consider these data when developing management objectives or regulations concerning these urban wintering mallard populations.en_US
dc.description.tableofcontentsChapter 1. Use of anthropogenic food subsidies by two high-latitude wintering mallard (Anas platyrhynchos) populations -- Chapter 2. Maintenance of low-pathogenic influenza A viruses and antibody response in high-latitude urban wintering mallards (Anas platyrhynchos) -- General Conclusions -- Appendices.en_US
dc.titleSeasonal variation in the health of high-latitude wintering mallards (Anas platyrhynchos)en_US
dc.identifier.departmentDepartment of Biology and Wildlifeen_US
dc.contributor.chairLindberg, Mark S.
dc.contributor.committeeO'Brien, Diane M.
dc.contributor.committeeRamey, Andrew M.

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    Includes WIldlife Biology and other Biological Sciences. For Marine Biology see the Marine Sciences collection.

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