Urban vultures preferentially roost at sites surrounded by more developed land cover and lower deer carcass density.

Abstract Land cover changes resulting from urbanization alter habitat structure and resource availability. Vultures provide ecosystem services such as nutrient cycling and may help limit disease transmission, making them an important feature of urban areas. Urbanization may have positive and negative impacts on vultures, such as increasing foraging opportunities and decreasing nesting success, complicating our understanding of the effect of urbanization on these species. We examined how local and landscape features affect roost attendance of black vultures ( Coragyps atratus ) and turkey vultures ( Cathartes aura ) to better understand the factors that play a role in site selection and habitat and landscape use. We counted the number of vultures at twenty-nine roosting sites in the Charlotte Metropolitan Area, NC once a month between November and March over two years. At each roosting site, we measured roosting structure height, vegetation height, and open space, and calculated the amounts of developed land cover, open water, developed-forest edge density, and deer carcass density in surrounding landscapes of 0.4 to 20km radii. The best model for roost attendance included wind speed, vegetation height, developed land cover within 15km, developed-forest edge density within 15km, deer carcass density within 15 and 20km, and survey date. Developed land cover was associated with higher roost attendance while other variables were associated with lower roost attendance. The effects of landscape variables on roost attendance suggests urban vultures are relying more on trash and anthropogenic food sources, which may alter nutrient cycling, disease dynamics, and reproductive success.