The Effect of Habitat Fragmentation on Mesocarnivore Relative Abundance in an Urban Landscape
University of Delaware
The objective of this study was to identify landscape variables associated with habitat fragmentation, which predicted the presence of mesocarnivores in urban landscapes. I used remote cameras to detect mesocarnivores in 21 urban forest fragments in Newark, Delaware. I conducted remote camera surveys June 2012 through July 2012 and June 2013 through July 2013. Using linear regression models, I determined if any of the following 6 landscape characteristics (i.e. proportion of multiflora rose cover within the plot; distance to the nearest road, stream, and house; patch size; and patch area to perimeter ratio) were related to species richness and relative abundance of northern raccoon (Procyon lotor), red fox (Vulpes vulpes), Virginia opossum (Didelphis virginiana), and domestic cat (Felis catus). Patch size was negatively related to species richness and relative abundance of raccoon, opossum, and cat, suggesting these 3 species utilize smaller patches while red fox, the only mesocarnivore with a positive relationship to patch size utilizes larger forest fragments. Species richness and raccoon relative abundance shared a negative relationship with distance to road, a likely result of high raccoon detection and their affinity for human-dominated landscapes. Domestic cats were positively related with patch area to edge ratio, contrary to red fox which was negatively related with patch area to edge ratio. While my research is only applicable to the 4 target species found in Newark forest patches, the results provide further insight to mesocarnivore habitat use within urban forest fragments.