The effects of black-tailed prairie dogs on shortgrass prairie diversity

Funding: U.S. Fish and Wildlife Service

Investigator: Justin Kretzer, M.S. Candidate

Advisor: Jack F. Cully, Jr.

Expected Completion Date: May 1998

Recent studies have demonstrated that there are a number of species that may be dependent on prairie dogs for the creation and maintenance of suitable habitat. Therefore, there has been great concern that the tremendous reduction in the abundance and distribution of prairie dogs over the last century has put a portion of the biotic diversity of the Great Plains at risk. The objective of this study is to determine the extent to which vertebrate (reptiles and amphibians) and invertebrate (ground beetles) diversity in a shortgrass prairie ecosystem is influenced by the presence of black-tailed prairie dog colonies. This study was conducted on the Cimarron National Grasslands, Kansas during the summers 1996 and 1997. Two treatments were established: areas colonized by prairie dogs; and areas not colonized by prairie dogs.

Ten species of reptiles and three species of amphibians were captured in both treatments combined. Amphibian and reptile species richness, evenness, and diversity did not differ significantly among treatments; however, reptile species composition differed between treatments. Abundance of western rattlesnakes (Crotalus viridis) over 2 years were significantly greater on prairie dog colonies than on non-colonized shortgrass sites. Conversely, the racer (Coluber constrictor) was more abundant in areas where prairie dogs are absent. The ornate box turtle (Terrapene ornata), six-lined racerunner (Cnemidophorus sexlineatus), Great Plains skink (Eumeces obsoletus), and milk snake (Lampropeltis triangulum) were unique to prairie dog colonies; while, the blackhead snake (Tantilla nigriceps) was only captured on non-colonized shortgrass prairie sites.

Ground beetles were captured using pitfall traps and are currently being sorted and identified to species level.