Genus Urocitellus Ground Squirrels

Urocitellus is a genus of ground squirrels. They were previously believed to belong to the much larger genus Spermophilus, but DNA sequencing of the cytochrome b gene showed that this group was paraphyletic to the prairie dogs and marmots, and could therefore no longer be retained as a single genus. As a result, Urocitellus is now considered as a genus in its own right.

All but two species are native to the northern and western parts of North America, from California and Minnesota through the north-western United States and western Canada; the Arctic ground squirrel inhabits Arctic terrain on both sides of the Bering Strait, while the long-tailed ground squirrel is exclusively found in Asia.

Species in this Gallery:

  • Northern Idaho Ground Squirrel (Urocitellus brunneus)

  • Wyoming Ground Squirrel (Urocitellus elegans)

  • Uinta Ground Squirrel (Urocitellus armatus)

  • Columbian Ground Squirrel (Urocitellus columbianus)

  • Richardson’s Ground Squirrels (Urocitellus richardsonii)

  • Arctic Ground Squirrel (Urocitellus parryii)

  • Belding's Ground Squirrel (Urocitellus beldingi)

The Northern Idaho Ground Squirrel (Urocitellus brunneus) is a species of the largest genus of ground squirrels. This species and the Southern Idaho ground squirrel were previously considered conspecific, together called the Idaho ground squirrel.

The species is about 233mm in length. The squirrel hibernates for 8 months and lives in dry meadows in Adams and Valley Counties in western-central Idaho.

In 2000, the species was classified as threatened under the Endangered Species Act due to many threats.

The habitat of the northern Idaho ground squirrel consists of dry rocky meadows. Ground with deep soil and scattered with ponderosa pine and Douglas-fir forests at the elevation between 915 to 1,650 meters is the preferred habitat of the squirrels. Original vegetation in the habitat of the NIDGS was big sage brush, bitterbrush, native bunch grasses, and forbs, but now the area contains cheatgrass and medusahead.

During the winter, the NIDGS hibernates in environments with larger coverage compared to the active season habitats. The NIDGS mainly hibernates at a completely different habitat than the active season habitat.

The northern Idaho ground squirrel lives in the Adams and Valley Counties in western-central Idaho. The species used to occupy 1,600km2, but now the species only occupies less than 20km2.

Predators of the northern Idaho ground squirrel consist of: badgers, prairie falcons, Cooper's hawk, goshawks, red-tailed hawks, northern harriers, coyotes, and long-tailed weasels. The species only has one mating call for predators, which are given mostly by female individuals when the young leave the nest.

Northern Idaho Ground Squirrel (Urocitellus brunneus) - Tamarack Idaho


Wyoming Ground Squirrel (Urocitellus elegans) - Southern Wyoming and Rocky Mountains National Park, Colorado (See a distribution map and one on this gallery).

The Uinta ground squirrel (Urocitellus armatus), commonly called a "chisler" and Potgut in northern Utah, is a species of rodent native to the western United States.

The Uinta ground squirrel is a moderately sized ground squirrel, measuring 28 to 30 cm (11 to 12 in) in total length. They weigh about 210 g (7.4 oz) when they emerge from hibernation, a figure that steadily increases until they are ready to hibernate again in the fall. Their fur is brown to cinnamon in color, being paler on the underside and grey on the sides of the head and neck. The 6 to 8 cm (2.4 to 3.1 in) tail is buff with a grey underside, as distinct from the ochraceous or reddish color found in closely related species such as Belding's or Wyoming ground squirrels. Females have ten teats.

First described from the Uinta Mountains, the squirrels are found in Wyoming west of the Green River, in southwestern Montana, eastern Idaho, and northern and central Utah. They inhabit open areas, such as meadows, pasture, and shrub-steppe habitats, at elevations between 1,220 and 2,440 m (4,000 and 8,010 ft). There are no recognised subspecies.

Uinta ground squirrels are primarily herbivorous, and mostly eat grass, seeds, and the leaves of forbs, along with a small amount of earthworms and discarded human food. The exact composition of the diet changes throughout the year. Their most common predators are coyotes, badgers, weasels, and raptors.

Although they often live in colonies, adults react aggressively towards one another outside of the breeding season, with females being more intolerant than males. Males mark their territories with scent glands in their cheeks, which they rub on the ground, but do not mark the entrances to their burrows. The squirrels greet one another by sniffing, escalating to threat postures and bristling the hair on their tails, and eventually to wrestling, boxing, and chasing if the intruder does not retreat.

The squirrels make six distinct vocalisations: chirps, squeals, squawks, trills, growls, and teeth clattering. These are used primarily as a means of gaining attention, and all are used in aggressive interactions between individuals. However, chirps are also used to warn of aerial predators, and trills to warn of predators on the ground, with squirrels hearing them either adopting an alert posture or running for their burrows.

Uinta ground squirrels are only active for a few months each year. Adult males wake from hibernation around mid March, but may wait a few weeks before emerging, depending upon the weather. Females emerge slightly later, followed by female and then male yearlings. Adults return to their burrows to hibernate between late July and mid August, with juveniles following about two weeks later.

During their active periods the squirrels are diurnal.

Uinta Ground Squirrel (Urocitellus armatus) - Yellowstone National Park, Grand Tetons NP, Wasatch Mountains Brighton

Belding's Ground Squirrel (Urocitellus beldingi), also called pot gut, sage rat or picket-pin, is a squirrel that lives on mountains in the western United States. In California, it often is found at 6,500 to 11,800 feet (2,000–3,600 m) in meadows between Lake Tahoe and Kings Canyon. This species is not of conservation concern, and its range includes some protected areas.

The Belding's ground squirrel is medium-sized with "a relatively short tail, short limbs, and small ears".[3] It has a gray pelage become more cinnamon at the underside and reddish-brown on the back. Its body length is 230 to 300 millimetres (9.1–11.8 in). The tail is 44 to 76 millimetres (1.7–3.0 in) and is bushy but also flattened. The distal hairs of the tail have three color bands, one black, one white and one red. On average, the ground squirrel weighs 290 grams (0.64 lb). Its feet are covered in little to no hair. Compared to other ground squirrel species, its cheek pouches are moderate in size.

Being native to the northwestern United States, the Belding's ground squirrel ranges covers northeastern Oregon and part of Washington, north California, southwestern Idaho, north and central Nevada and northwestern Utah. The ground squirrel prefers to live at higher altitudes, occurring in alpine and subalpine meadows.[5] It is also found in sagebrush flats, brush/grass habitats and cultivated areas. The grounds squirrels are largely restricted to open areas with enough fresh vegetation and water. They do not live in dense forests, tall grasses, rocky slopes or thick shrubbery as they cannot watch for predators. In addition they do not prefer grass that is too short as they cannot hide from predators.

Belding’s Ground Squirrel (Urocitellus beldingi) - Saddlebag Lake & Yosemite National Park California

The Columbian ground squirrel (Urocitellus columbianus) is a species of rodent common in certain regions of Canada and the northwestern United States. It is the second largest member of the genus Urocitellus, which is part of the tribe Marmotini, along with marmots, chipmunks, prairie dogs, and other holarctic ground squirrels. They are stout, with short dense fur, which is characteristically tawny across the bridge of the nose. Social encounters sometimes are initiated with kissing behavior and the most common activity above ground is standing at attention. Residing in mountainous terrain and high plains in northern latitudes, they hibernate for 8 to 9 months of the year in burrows, which may be used for many years. They are emaciated when emerging in the spring. The Columbian ground squirrel came to the attention of the scientific community through writings produced by Lewis and Clark, while 21st century molecular genetics has more finely illuminated its ties with other close relatives.

The Columbian ground squirrel is one of the largest members of the genus, the largest being the Arctic ground squirrel. They have a relatively sturdy, robust build. They measure 325–410 mm (12.8–16.1 in) in length overall, with a tail measuring 80–116 mm (3.1–4.6 in). The hind feet measure 47–57 mm (1.9–2.2 in) and the ear 16–22.5 mm (0.63–0.89 in).

The hair is dense and relatively short. The facial fur is bronze across the bridge of the nose. The fur along the back, legs, and feet is a more cinnamon buff, with darker fur closer to the body. There is a pale beige to buff ring of fur around the eye. The neck fur is gray along the sides of the cheeks. The flanks may be light beige or gray. They have a darker tail, with darker underfur and some lighter beige markings above and dark to grayish white below. Molting occurs diffusely, without a clear line of delineation.

Columbian ground squirrel at burrow entrance

Two subspecies have been described, which vary in appearance. Compared with U. c. columbianus, the population U. c. ruficaudus has a tail more rufous and less gray above. The sides of the face and throat are also more deeply rust shaded. The legs and feet are darker as well. The skull of U. c. ruficaudus is broader, with more robust zygomatic arches.

Several albino variants have been found. An albino squirrel was captured alive by a student near Pullman, Washington in 1932. It had been in an alfalfa field. The animal had white hair and pink eyes. A zoologist reported intentions to keep the animal alive to study genetic inheritance patterns. The following year, he reported finding three more young albinos in the same area. Around 30 years prior, two albino skins had been collected, also near Pullman. It was proposed that the recessive trait persisted in the locality, appearing at sporadic intervals.

The Columbia ground squirrel is found in western areas of North America. It occurs in the Rocky Mountains, from as far north as western Alberta and southeastern British Columbia. They are found in the western parts of Montana, through central Idaho and into northern and eastern reaches of Washington. They are also found along plains of eastern Washington. In Oregon, they occur in mountainous area in the east-central part of the state. They reside between 700–8,000 feet (210–2,440 m) in elevation.

The known fossil record of the Columbia ground squirrel consists of specimens recovered from the Wasden fossil site (Owl Cave) in Bonneville County, Idaho.[5] Fossils from this site date to the late Pleistocene (Rancholabrean). The site is located at 1,584 metres (5,197 ft) elevation. Fossils of small mammals deposited at this site are primarily attributed to owl predation.

The distribution of the Columbia ground squirrel in Oregon was assessed based on consideration of animals obtained in 71 localities. Over 98% were obtained in the Blue Mountains ecoregion, which includes the Wallowa and Blue Mountain ranges. The remaining squirrels came from the Owyheee Uplands.

Columbian Ground Squirrel (Urocitellus columbianus) - Glacier National Park, Montana (scanned slides from years ago)

 The Arctic Ground Squirrel (Urocitellus parryii) is a species of ground squirrel native to the Arctic and Subarctic of North America and Asia. People in Alaska, particularly around the Aleutians, refer to them as "parka" squirrels, most likely because their pelt is good for the ruff on parkas and for clothing.

The Arctic ground squirrel has a beige and tan coat with a white-spotted back. This squirrel has a short face, small ears, a dark tail and white markings around its eyes. Arctic ground squirrels undergo a coat change from summer to winter. Summer coats include red/yellow colorations along the cheeks and sides of the animal. In fall, these red patches are replaced with silvery fur. The average length of an Arctic ground squirrel is approximately 39 cm (15 in). Since Arctic ground squirrels undergo drastic seasonal changes in body mass, it is difficult to give an average mass, but for adult females it is close to 750 g (26 oz), however, males generally are around 100 g (3.5 oz) heavier than females.

The Arctic ground squirrel can be found in regions of Northern Canada ranging from the Arctic Circle to northern British Columbia, and down to the southern border of the Northwest Territories, as well as Alaska and Siberia.

The Arctic ground squirrel is native to the North American Arctic tundra, where its main habitats are on mountain slopes, river flats, banks, lakeshores and tundra ridges of the arctic tundra. Ground squirrels live in sandy soil due to easy digging and good drainage. Arctic ground squirrels make shallow burrows in areas where the permafrost does not prevent them from digging. The Arctic ground squirrel inhabits dry Arctic tundra and open meadows in the most southern habitats of this species.

Arctic Ground Squirrels (Urocitellus parryii) - Alaska and Mt Saint Elias, Yukon Canada

Richardson's ground squirrel (Urocitellus richardsonii), also known as the dakrat or flickertail, is a North American ground squirrel in the genus Urocitellus. Like a number of other ground squirrels, they are sometimes called prairie dogs or gophers, though the latter name belongs more strictly to the pocket gophers of family Geomyidae, and the former to members of the genus Cynomys.

Native to the short grass prairies, Richardson's ground squirrel is found mainly in the northern states of the United States, such as North Dakota and Montana, and in western Canada, including central and southern Alberta and southern Saskatchewan. The range of this animal expanded as forests were cleared to create farmland. They are not simply restricted to prairie; sometimes they adapt to suburban environments, causing them to be seen as pests because of the burrows they dig. It is not unusual to find squirrels digging tunnels under the sidewalks and patios of urban homes

Richardson’s Ground Squirrels (Urocitellus richardsonii) - Montana (scanned slides; ID unconfirmed; location unconfirmed)