Great Basin Naturalist Memoirs


The black-footed ferret (Mustela nigripes) occupied area lies in the western Big Horn Basin, Park County, Wyoming. Cody, a nearby town, shows a record high temperature of 40.5 C and a low of -43.3 C, with 173 days each year below 0 C. Area geology is dominated by Absaroka volcanics. Soils are shallow (0.5 m) and underlain by unconsolidated gravels; well-drained, medium-textured clay-loams (ca 1 m in depth); or clays derived from shale parent materials. Vegetation is characterized by a wheatgrass-needlegrass shrubsteppe type (Agropyron/Stipa/Artemisia). Prior to white settlement, the area hosted a diverse large mammal community. First white settlements began 1878–1885, with establishment of several area ranches. Predator and prairie dog (Cynomys Leucurus) poisoning began about 1884. Heavy livestock grazing of public ranges followed the demise of bison (Bison bison) by 1890, which likely was conducive to a continuation of an ungulate-range relationship favoring prairie dog habitat. Ferret specimens from Crow Indian inhabitants of the region dated to 1880s and two specimens from Park County date from the 1920s–1930s. Today ferrets are found on white-tailed prairie dog colonies (a "complex") totaling ca 2,995 ha. The areas occupied by these colonies are equally owned by private, state, and federal interests. Evidence shows, many abandoned prairie dog colonies which, along with the current ones total about 8,400 ha. Many of them may have been active simultaneaously prior to poisoning in the 1930s.