Habitat and distribution of the Wyoming pocket gopher (Thomomys clusius)

The Wyoming pocket gopher (Thomomys clusius) is among the least understood species of Geomyidae. It was petitioned for listing under the United States Endangered Species Act in 2007, but found not warranted for listing because of the poor state of knowledge. As of 2008, it was only known from a handful of specimens and a coarse, qualitative assessment of the landscape from which they were collected. To begin resolving this problem, we investigated the distribution and habitat use of T. clusius by conducting pocket gopher surveys across its known range and the adjacent, previously unsurveyed, landscape. We compared habitat features at sites occupied by T. clusius to unoccupied sites and those occupied by the common northern pocket gopher (T. talpoides). We found that T. clusius was uncommon throughout a very limited range that was completely encompassed by T. talpoides, and that habitat occupied by the 2 species differed. In contrast to T. talpoides, T. clusius was more restricted to areas with Gardner's saltbush, often in combination with other moderately halophytic species typically found in relatively flat areas of fine-textured soil. Its restricted range, relatively rarity, and association with limited habitat all suggest that T. clusius could be sensitive to habitat change. As such, monitoring populations in the face of impending changes may be important to its long-term conservation.