Assessing Occurrence and Habitat Characteristics of the Southeastern Pocket Gopher (Geomys pinetis)

Abstract

The southeastern pocket gopher (Geomys pinetis), a species of conservation concern in Florida, Georgia, and Alabama, is of increasing conservation concern due to a range wide decline believed to be due to habitat loss and fragmentation. There is a strong need to better understand the southeastern pocket gopher’s occurrence in relation to vegetation attributes and habitat management. To gain better insight to the species it is important to develop new and creative ways to survey and assess occurrence efficiently. I used imagery in the Google Earth platform to assess presence of southeastern pocket gophers based on their soil mounds at 77 sites in Alabama, Florida, and Georgia, and compared imagery survey results to those of independent field surveys of these sites. I recorded imagery detections of mounds at 22 of 23 sites where presence of pocket gophers was observed in the field for a true positive rate of 96%. Additionally, I examined habitat factors associated with the presence of southeastern pocket gophers at a study site in southeast Alabama by using a case-control design. I measured vegetation structure and soil texture in 62, 0.1 ha sites occupied by southeastern pocket gophers and 62 unoccupied sites. All occupied sites at the study site in Alabama had a clay content below 8.05% within the 0-20 cm of soil; this attribute had overwhelming support as the most important single variable separating occupied and unoccupied sites. Logistic regression modeling to compare vegetation of occupied and unoccupied sites identified the quadratic effect of canopy cover as the model with highest support. The data obtained from this project, as well as the methodology, provides vital information that will aid in future pocket gopher conservation efforts.