SREL Reprint #3682

Influence of landscape attributes on Virginia opossum density

David A. Bernasconi1, Wesley C. Dixon1, Matthew T. Hamilton2, James L. Helton1, Richard B. Chipman3, Amy T. Gilbert4, James C. Beasley1, Olin E. Rhodes Jr.5, and Guha Dharmarajan6

1Savannah River Ecology Laboratory, Warnell School of Forestry and Natural Resources,
University of Georgia, Drawer E, Aiken, SC 29802, USA
2Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA
3National Rabies Management Program, USDA, APHIS, Wildlife Services, Concord, NH 03301, USA
4National Wildlife Research Center, USDA, APHIS, Wildlife Services, Fort Collins, CO 80521, USA
5Savannah River Ecology Laboratory, Odum School of Ecology, University of Georgia,
Drawer E, Aiken, SC 29802, USA
6Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken, SC 29802, USA

Abstract: The Virginia opossum (Didelphis virginiana), North America's only marsupial, has a range extending from southern Ontario, Canada, to the Yucatan Peninsula, Mexico, and from the Atlantic seaboard to the Pacific. Despite the Virginia opossum's taxonomic uniqueness in relation to other mammals in North America and rapidly expanding distribution, its ecology remains relatively understudied. Our poor understanding of the ecology of this important mesopredator is especially pronounced in the rural southeastern United States. Our goal was to estimate effects of habitat on opossum density within an extensive multi-year spatial capture-recapture study. Additionally, we compared the results of this spatial capture-recapture analysis with a simple relative abundance index. Opossum densities in the relatively underdeveloped regions of the southeastern United States were lower compared to the more human-dominated landscapes of the Northeast and Midwest. In the southeastern United States, Virginia opossums occurred at a higher density in bottomland swamp and riparian hardwood forest compared to upland pine (Pinus spp.) plantations and isolated wetlands. These results reinforce the notion that the Virginia opossum is commonly associated with land cover types adjacent to permanent water (bottomland swamps, riparian hardwood). The relatively low density of opossums at isolated wetland sites suggests that the large spatial scale of selection demonstrated by opossums gives the species access to preferable cover types within the same landscape.

Keywords: abundance index, Didelphis virginiana, landscape ecology, population density, southeast United States, spatial capture-recapture, telemetry, Virginia opossum

SREL Reprint #3682

Bernasconi, D. A., W. C. Dixon, M. T. Hamilton, J. L. Helton, R. B. Chipman, A. T. Gilbert, J. C. Beasley, O. E. Rhodes Jr., and G. Dharmarajan. 2022. Influence of landscape attributes on Virginia opossum density. The Journal of Wildlife Management 86(7): e22280.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).