Squirrels are members of the family Sciuridae, a family that includes small or medium-sized rodents. The squirrel family includes tree squirrels, ground squirrels, and flying squirrels. Squirrels are indigenous to the Americas, Eurasia, and Africa, and were introduced by humans to Australia. The earliest known fossilized squirrels date from the Eocene epoch, and among other living rodent families, the squirrels are most closely related to the mountain beaver and to the dormice.
The California ground squirrel, also known as the Beechey ground squirrel, is a common and easily observed ground squirrel of the western United States and the Baja California Peninsula; it is common in Oregon and California and its range has relatively recently extended into Washington and northwestern Nevada. Formerly placed in Spermophilus, as Spermophilus beecheyi, it was reclassified in Otospermophilus in 2009, as it became clear that Spermophilus as previously defined was not a natural (monophyletic) group. A full species account was published for this species in 2016.
Ground squirrels are rodents of the squirrel family (Sciuridae) that generally live on the ground or in burrows, rather than in trees like the tree squirrels. The term is most often used for the medium-sized ground squirrels, as the larger ones are more commonly known as marmots or prairie dogs, while the smaller and less bushy-tailed ground squirrels tend to be known as chipmunks.
Franklin's ground squirrel is a species of squirrel native to North America, and the only member of the genus Poliocitellus. Due to the destruction of prairie, the populations of Franklin's ground squirrel have dwindled, approaching levels of concern. Its decline in the eastern portion of its range is mostly attributed to habitat fragmentation.
The Mohave ground squirrel is a species of ground squirrel found only in the Mojave Desert in California. The squirrel was first described in 1886 by Frank Stephens of San Diego. It is listed as a threatened species under the California Endangered Species Act, but not under the federal Endangered Species Act. The IUCN lists this species as near threatened.
Belding's ground squirrel, 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 thirteen-lined ground squirrel, also known as the striped gopher, leopard ground squirrel, and squinny, is a ground squirrel that is widely distributed over grasslands and prairies of North America.
Heermann's kangaroo rat is a species of rodent in the family Heteromyidae. Their long smooth pelage resembles typical kangaroo rats, with their dorsal side showing a mixed range of olive, black and orange colors. There are 9 distinguished sub-species of Dipodomys heermanni: D.h. arenae, D.h. berkeleyensis, D.h. dixoni, D.h. goldmani, D.h. heermanni, D.h. jolonensis, D.h.morroensis, D.h. swarthi, and D.h. tularensis. The dental formula of Dipodomys heermanni is 1.0.1.31.0.1.3 × 2 = 20.
The tropical ground squirrel is a species of rodent in the family Sciuridae. At one time the species was originally described as Spermophilus adocetus, but the genus Spermophilus was revised and subdivided in 2009 and it was placed in the genus Notocitellus. It is endemic to arid upland areas and deciduous woodland in Mexico. It is locally referred to as Cuinique.
The ring-tailed ground squirrel is a species of rodent in the family Sciuridae. It is endemic to the Pacific coast region of central Mexico. It is a common species and feeds mainly on fruits and nuts. The IUCN has assessed it as being of "least concern".
The Columbian ground squirrel 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 Daurian ground squirrel is a species of rodent in the family Sciuridae. It is found in China, Mongolia, and Russia.
The Perote ground squirrel is a species of rodent in the family Sciuridae. It is endemic to Mexico and is currently at risk of extinction. Perote ground squirrels live within the same area as rock squirrels but they use different microhabitats. In one case it also shares its habitat with the Mexican ground squirrel.
The spotted ground squirrel is a species of ground squirrel in the rodent family Sciuridae. It is found throughout Mexico and the central and western United States. Characterized by a white spotted back, the spotted ground squirrel is one of the smallest squirrels found in North America. They are mainly herbivorous, but also eat insects. A burrowing mammal, the spotted ground squirrel will make tunnels to store its food, as well as shelter and hibernation quarters.
The speckled ground squirrel or spotted souslik is a species of rodent in the family Sciuridae from Eastern Europe. Spermophilus suslicus consists of three subspecies: S. s. boristhenicus, S. s. guttatus, and S. s. suslicus. It is threatened by habitat loss.
Townsend's ground squirrel is a species of rodent in the family Sciuridae. It is found in high desert shrublands in several areas of the United States.
The rock squirrel is a species of rodent in the family Sciuridae. It is native to Mexico and the Southwestern United States, including southern Nevada, Utah, Colorado, Arizona, New Mexico, West Texas, and the panhandle of Oklahoma.
Mearns's squirrel is a subspecies of the Douglas squirrel endemic to Mexico. It is endangered and occurs in low densities, and is threatened by habitat loss. It is possibly also threatened by competition from the eastern gray squirrel, which was introduced to the range of Mearns's squirrel in 1946, but may not be present anymore. It is closely related to other subspecies of the Douglas squirrel, but far less is known about its behavior, which was first studied in detail in 2004. It is named for the 19th-century American naturalist Edgar Mearns.
Spermophilus brevicauda is a species of rodent in the family Sciuridae. It is found in eastern Kazakhstan and the northern half of the Xinjiang region of China.
Pygmy ground squirrels are small ground squirrels in the genus Xerospermophilus, family Sciuridae, containing four species from Mexico and the United States. The members of this genus were formerly placed in the large ground squirrel genus Spermophilus. Since DNA sequencing of the cytochrome b gene showed that Spermophilus was paraphyletic to the prairie dogs and marmots, this group is now separated, along with six other genera. Within the genus, the Mohave ground squirrel and the round-tailed ground squirrel were thought to be close relatives, sometimes a subgenus Xerospermophilus, while the spotted ground squirrel and the Perote ground squirrel were formerly placed in the subgenus Ictidomys.
