Raccoons and opossums respond similarly to high and low development in the East Texas Pineywoods

Abstract

Over the last half-century, cities across the southeastern United States have experienced consistent human population growth, which has increased the rate of urban sprawl and subsequent habitat fragmentation with resource subsidies from development. The northern raccoon (Procyon lotor) and Virginia opossum (Didelphis virginiana) are mesopredators commonly associated with and benefiting from urbanized areas. We conducted a small-scale study of raccoons and opossums within the Nacogdoches, Texas, in January 2014. We captured and marked individual raccoons and opossums and used occupancy and spatial-capture-recapture models to examine habitat use, detection, and population density in high- and low-density urban study areas. We predicted to find high densities of each mesopredator, relative to other studies in larger metropolitan areas. We also expected to find a response to landscape features in the high-development study area to be closely associated with anthropogenic features and proximity to water, but less pronounced in the low-development study area. Contrary to our predictions, the detectability of each species in the high-development study area had a positive association with areas further from buildings, and raccoon habitat use had a positive association farther from natural water. Similarly, in the low-development study area, we found raccoon detectability had a positive association with areas farther from the urban edge and opossums had a positive association with areas with smaller forest patches (i.e., edge habitat). We were able to estimate 13.66 raccoons/km2 (95% CI 7.10–26.30) in the high-development study area and 12.55 opossums/km2 (95% CI 04.36–36.15) in the low-development study area. Our results indicate high densities of each species, and the first urban density of Virginia opossum using spatial-capture-recapture methods which further supports that these mesopredators are adapted to and benefit from urban-derived resources in urban areas. This study highlights the adaptability of these small mesopredators and the need for managers to consider adaptive strategies across different urban intensities as the ecology of these species may differ as compared to larger cities.