In September 1981, a ranch dog named Shep dropped a strange kill on a porch near Meeteetse, Wyoming. Inadvertently solved a mystery biologists thought was closed for good. The dead animal was a black-footed ferret, a species presumed extinct for years. The wild colony that turned up nearby was living entirely inside white-tailed prairie dog burrows. Every ferret reintroduction site chosen since has depended on the same rodent: a stocky, buff-colored prairie dog that spends nearly half the year asleep underground and builds looser, thinner colonies than its more famous relatives on the Great Plains.
A high-country prairie dog with a telltale tail
White-tailed prairie dogs run about 12 to 16 inches long and weigh roughly 1.7 to 3.3 pounds, with a yellowish buff-brown coat and a dark brown-black patch above and below each eye. The name comes from the field mark that actually separates it from its cousins: a short, white-tipped tail, in place of the black tip of a black-tailed prairie dog or the pale gray tip of a Gunnison’s. It also lives higher than any other US prairie dog, typically between 5,000 and 10,000 feet, on sagebrush flats and high-desert basins across western Wyoming and western Colorado, with smaller outposts in eastern Utah and southern Montana. Wyoming holds the largest populations by far, where old-timers still call the species “chiselers.”
Loose family clusters, not crowded towns
Unlike the black-tailed prairie dog, which packs thousands of animals into dense, contiguous towns, this species spreads out into small family clusters, sometimes called coteries, scattered across a much larger area of sagebrush steppe and high grassland. Colonies communicate with barks and visual posturing rather than the elaborate vocal repertoire of denser-living relatives. Individual burrow systems sit farther apart. They graze mostly on grasses, sedges. Forbs, favoring forbs when they’re available. Forage through the morning and afternoon before retreating underground during the hottest part of the day.
One of the few ground squirrels that truly hibernates
Most people picture a black-tailed prairie dog town, active through the winter with animals popping up on mild days. White-tailed prairie dogs behave nothing like that. They are spontaneous hibernators, meaning they stop eating and drop into deep torpor on their own schedule each autumn, rather than being forced into brief cold-triggered dormancy the way black-tailed prairie dogs occasionally are. A colony can spend five or six months of the year completely underground and inactive. Males surface first in late February or early March. Females follow two to three weeks later, compressing courtship, mating. Rearing into a short active season. Litters average about 5.5 pups after a gestation of roughly 30 days, one litter per year. Females don’t typically breed until their second spring.
Predators, plague. The ferret it unknowingly protects
Golden eagles, American badgers. Black-footed ferrets are the species’ main predators. That last relationship cuts both ways. The U.S. Fish and Wildlife Service considers a healthy white-tailed prairie dog colony, generally at least 3,000 acres, the minimum habitat needed to support a reintroduced ferret population, since ferrets eat almost nothing else and den in prairie dog burrows year-round. That dependency nearly doubled the tragedy at Meeteetse: the wild ferret population discovered there in 1981 collapsed in 1986 after canine distemper and sylvatic plague swept through. Only 18 animals were pulled into captivity to found today’s captive-breeding program. Ferrets weren’t released back at Meeteetse until 2016. Sylvatic plague, a non-native flea-borne bacterium, remains the biggest threat to the prairie dogs themselves, on top of historical shooting and poisoning campaigns that have shrunk the species to roughly a tenth of its original range. Despite that contraction, the IUCN still rates it Least Concern.
Telling it apart from Gunnison’s and black-tailed prairie dogs
Range narrows the guesswork first. Black-tailed prairie dogs dominate the shortgrass plains east of the Rockies, into places like eastern Colorado and Wyoming’s plains country, while Gunnison’s prairie dogs hold the Four Corners region across New Mexico, Arizona, Colorado, and Utah. Where the three overlap along Colorado’s Front Range and southern Wyoming, tail color settles the question at a glance: white in this species, solid black in the black-tailed prairie dog. A duller grayish-white confined to just the tip in Gunnison’s. Body size helps too, since Gunnison’s prairie dogs run smaller and shorter-tailed than either of the others. If the animal is denning at elevation on sagebrush flats rather than open shortgrass plains. The tail flashes pale rather than dark when it bolts for its burrow, it’s a white-tailed prairie dog.
