PARENT SESSION

Community Ecology 3 -- Session Chair: Catherin Schwemm-- Van Duzer Theater

CHANGES IN MESOPREDATOR COMMUNITY STRUCTURE IN RESPONSE TO URBANIZATION. Suzanne Prange^1,2 and Stanley D. Gehrt^1,2. ¹ Max McGraw Wildlife Foundation, P.O. Box 9, Dundee, IL, USA; ² Ohio State University, School of Natural Resources, 2021 Coffey Road, Columbus, OH, USA.

ABSTRACT- Raccoons (Procyon lotor), Virginia opossums (Didelphis virginiana), and striped skunks (Mephitis mephitis) are common urban inhabitants, share many ecological characteristics, and presumably respond to urbanization in similar ways. We addressed their relative response to urbanization by identifying mesopredator community structure in large and small patches of habitat in northeastern Illinois. We selected patches of each size category within urban, suburban, and rural matrices. We used road-survey and trapping data to examine effects of site, season, year, and their interaction on community structure. Raccoons dominated the mesopredator community at all sites for both sampling types, but the relative abundance of the other species exhibited some variation. For large sites, the site*season model was most parsimonious for both data sets and relative occurrence of opossums and skunks was higher at the rural site (P < 0.001 for all tests). For small sites, the site model best fit the road-survey data, with a higher relative occurrence of skunks at the rural site (² = 21.06, df = 1, P < 0.001). The season model best fit the trapping data, although the site*season model received moderate support. Despite similarities among these species, our data indicated they do not respond similarly to urbanization. Raccoons exhibited a greater demographic response, suggesting they exploit anthropogenic resources more efficiently. A disparity in anthropogenic resource use may be explained by differences in body size, competitive abilities, intraspecific tolerance, or the role of learning in foraging behaviors.

KEY WORDS: mesopredators, anthropogenic resources, urbanization, community structure