Ecological Interactions Between Two Ecosystem Engineers: Gunnison's Prairie Dog and Botta's Pocket Gopher

Abstract

We examined ecological interactions between two ecosystem engineers, Gunnison's prairie dogs (Cynomys gunnisoni) and Botta's pocket gophers (Thomomys bottae), across a 67,000-km2 range of northern Arizona. We examined densities of burrows, composition of vegetation, and characteristics of soil associated with locations where each species occurred alone and compared them to where they were both present. Density of T. bottae was significantly lower in the presence of C. gunnisoni than where occurring alone, while density of C. gunnisoni more than doubled at locations where they occurred with T. bottae compared to where they were alone. Vegetational communities associated with locations where C. gunnisoni occurred alone were significantly different from locations where T. bottae occurred alone and where both species were present. We also detected that burrows of T. bottae and C. gunnisoni occurred in soils that did not differ significantly in depth, texture, or rock content, but characteristics of soil played an influential role in patterns observed in vegetational communities.