The Effects of Urbanization on Stress and Immunity in White Ibis (Eudocimus albus)


Meeting Abstract

P2-53.1  Friday, Jan. 5 15:30 – 17:30  The Effects of Urbanization on Stress and Immunity in White Ibis (Eudocimus albus) CUMMINGS, CR*; KAHN, NY; MURRAY, M; ELLISON, TJ; WELCH, CN; HERNANDEZ, SM; NAVARA, KJ; University of Georgia; University of Georgia; University of Georgia; University of Georgia; University of Georgia; University of Georgia cummings.carolineruth@gmail.com

Changes in land-use due to rising human populations are affecting wildlife as natural habitats become more urbanized or are degraded. The ability of a species to adapt to urban environments and the associated novelty is important when considering conservation of species for when suitable habitat has disappeared. Exposure to urban environments can have dramatic impacts on the health and physiology of wildlife, however many species are still abundant in these environments, including white ibis (Eudocimus albus). While they originate in and breed in remote wetland habitats, some populations of white ibis can be found foraging in urban parks throughout Palm Beach County, FL. Further, their diet has shifted from protein-rich crustaceans and insects to carbohydrate-dense “junk” food, either as a result of anthropogenic feeding or foraging in human-generated landfills. The impacts of the shift away from their natural habitat and diet on their physiology, behavior, and vectors of zoonotic disease is vital to their conservation and management. We hypothesized that “urban” ibis would exhibit higher levels of stress and would show inhibited immunity. To determine this, we captured ibis from both “urban” and natural populations and tested for bacteriocidal capacity (via bacterial killings assays) and circulating corticosterone levels at various times of capture to measure acute and chronic stress levels. These parameters were then compared between the two populations of ibis. Contrary to our hypothesis, urban ibis are significantly better killers of E. coli and Salmonella than their natural wetland counterparts. The significance of these results and their relationship to plasma corticosterone will be discussed.

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