Tunnel Diameter as a Noninvasive Method of Detecting Pocket Gopher (Geomyidae) Occupancy

Challenges in monitoring rare and elusive species often involve low detection and sampling success. Noninvasive methods have allowed researchers to more efficiently monitor rare and elusive species while reducing costs of more invasive, traditional techniques. We evaluated the use of a noninvasive method as an alternative to live-trapping pocket gophers. We found that tunnel diameter can be used to help distinguish between occupancy by the Wyoming pocket gopher (Thomomys clusius; a species of conservation concern) and its more abundant and widespread congener, the northern pocket gopher (T. talpoides). Our method reduces reliance on more invasive methods of monitoring occupancy (i.e., live- or kill-trapping) for co-occurring pocket gopher species, and likely can be extended to survey for other species of fossorial mammals.