RESPONSES OF
WOOD STORKS TO
HUMAN-INDUCED LANDSCAPE CHANGE

URBAN FOOD SUBSIDIES REDUCE NATURAL FOOD LIMITATIONS
AND REPRODUCTIVE COSTS FOR A WETLAND BIRD

There is a strong conservation need to understand traits of native species that adapt to urban environments, but results have been equivocal. Wetland birds have shown a strong phylogenetic signal towards urban tolerance; however, these species have largely been ignored in urban studies. In their historic ranges, wetland birds inhabit dynamic systems, traveling long distances to locate food. This evolutionary adeptness of exploiting resources may translate to success in urban environments as these areas are characterized by novel food opportunities. We used Wood Storks (Mycteria americana), a wetland species of conservation concern, to determine if the ability to exploit resources in natural environments translated to exploitation of urban resources. We found that when wetlands offered optimal foraging conditions, storks nesting in both urban and natural wetlands had narrow diet breadths and high reproductive success. However, when natural wetlands offered poor foraging conditions, urban storks expanded their diet more than natural wetland nesting storks, to include anthropogenic prey items. Urban storks also had greater productivity than storks nesting in natural wetlands and therefore paid a lower penalty when wetlands offered suboptimal foraging conditions. Our study provides a mechanistic understanding of how a wetland species persists, and even thrives, in an urban environment. We demonstrated that species inhabiting dynamic systems can exploit urban areas which result in increased reproductive performance during suboptimal natural system conditions. Together, urban environments may support biodiversity in a variety of ways, but species-specific mechanistic understanding will help highlight how to best mitigate the potential threats of urbanization.