Family: Sciuridae, Squirrels view all from this family
Description Yellowish buff mixed with black above; slightly paler below. Short, white-tipped tail. Terminal half of tail grayish white in center. L 12 1/8–14 3/4" (309–373 mm); T 1 1/2–2 5/8" (39–68 mm); HF 2–2 1/2" (52–63 mm); Wt 23–42 oz (650–1,200 g).
Similar Species White-tailed and Utah prairie dogs have white in center of tail rather than grayish. Black-tailed Prairie Dog’s tail has black tip.
Breeding 1 litter per year of 1–8 young, born in early May; gestation 27–33 days.
Habitat Shortgrass prairies in high mountain valleys and plateaus of southern Rocky Mountains at elevations of 6,000–12,000’ (1,800–3,600 m). Habitat is much more variable topographically and vegetationally than that of the Black-tailed Prairie Dog, which occurs at lower elevations.
Range Southeastern Utah, s and c Colorado, ne and c Arizona, and nw New Mexico.
Discussion Gunnison’s Prairie Dog, like the rest of its kin, is active only when the sun is up, and is most energetic near dawn and dusk. It is constantly vigilant while aboveground, often sitting upright on its hindfeet while it pursues its main activities: mainly feeding, but also grooming and playing. This animal generally is seen from April to October. It is inactive in winter, living on stored body fat, and probably hibernates. It usually emerges in April, though tracks were once found in the snow in late March. Gunnison’s Prairie Dog feeds on green vegetation, particularly grasses, but also forbs, sedges, and shrubs, as well as a few insects. Its colonies are generally smaller and less closely knit than those of other prairie dogs, resembling ground squirrel aggregations, with fewer than 50 to 100 individuals. The animals in the colony cannot always see one another because their habitat is in such varied and patchy terrain, which is caused in part by human activities. On flat ground—and where this prairie dog is protected, such as at Blue Mesa Reservoir in Gunnison County, Colorado—where contact among colony members can be bettered managed, colonies are much larger and more extensive. This species’ burrow systems are shallower than those of the Black-tailed Prairie Dog, and contain a single nest. Burrows have neither food storage nor excrement chambers, as these animals usually feed and defecate outside. Territoriality is not well developed in Gunnison’s Prairie Dog, although old males may defend small areas outside their burrows. Mother-young relationships form the basic social unit. Newborns remain in the burrow about three weeks before emerging and are weaned about three weeks later. The female sits almost straight up on her haunches to nurse her young, who suckle either pectoral or inguinal (hindleg) nipples. Gunnison’s alarm call, distinctive among prairie dogs, is important to the survival and structure of the community. It is a series of high-pitched barks of one or two distinct syllables, with the second syllable lower and more guttural. The call may be repeated frequently and may continue for as long as half an hour. It increases in intensity as danger escalates, and ends in chatter as the animal enters its burrow. Predators include American Badgers, Coyotes, weasels, and raptors. Plague (Yersina pestis), carried by fleas, can decimate populations of this species. However, humans, through their extermination programs, are the chief enemy of Gunnison’s Prairie Dog.
