Xerospermophilus | |
---|---|
Round-tailed ground squirrel in Phoenix, Arizona | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Rodentia |
Family: | Sciuridae |
Tribe: | Marmotini |
Genus: | Xerospermophilus Merriam, 1892 |
Species | |
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 has shown Spermophilus to be paraphyletic to the prairie dogs and marmots, [1] this group is now separated, along with six other genera. [2] 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 placed in the subgenus (now a genus) Ictidomys . [2]
The name of the genus is a combination of the Greek word xeros, "dry", and Spermophilus , which also comes from Greek, meaning "seed lovers". [2]
The four species in Xerospermophilus are listed below. These are the same species that were previously grouped in the subgenus Otospermophilus. [2]
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 members of the squirrel family of rodents (Sciuridae), which generally live on or in the ground, rather than trees. 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. Together, they make up the "marmot tribe" of squirrels, Marmotini, a division within the large and mainly ground squirrel subfamily Xerinae, and containing six living genera. Well-known members of this largely Holarctic group are the marmots (Marmota), including the American groundhog, the chipmunks, the susliks (Spermophilus), and the prairie dogs (Cynomys). They are highly variable in size and habitus, but most are remarkably able to rise up on their hind legs and stand fully erect comfortably for prolonged periods. They also tend to be far more gregarious than other squirrels, and many live in colonies with complex social structures. Most Marmotini are rather short-tailed and large squirrels. At up to 8 kg (18 lb) or more, certain marmots are the heaviest squirrels.
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.
Spermophilus is a genus of ground squirrels in the squirrel family. As traditionally defined the genus was very species-rich, ranging through Europe, Asia and North America, but this arrangement was found to be paraphyletic to the certainly distinct prairie dogs, marmots, and antelope squirrels. As a consequence, all the former Spermophilus species of North America have been moved to other genera, leaving the European and Asian species as true Spermophilus.
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.
The thirteen-lined ground squirrel, also known as the striped gopher, leopard ground squirrel, squinney,, is a ground squirrel that is widely distributed over grasslands and prairies of North America.
The round-tailed ground squirrel, known as "Ardillón cola redonda" in Spanish, live in the desert of the Southwestern United States and Northwestern Mexico. They are called "ground squirrels" because they burrow in loose soil, often under mesquite trees and creosote bushes.
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 Baja California rock squirrel is a species of rodent in the family Sciuridae. It is endemic to Baja California, Mexico.
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 Sierra Madre ground squirrel is a species of rodent in the squirrel family. It is endemic to the Sierra Madre Occidental, in northern Mexico. Its natural habitat is subtropical or tropical dry lowland grassland.
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. Perote ground squirrels have traits similar to those of spotted ground squirrels found in the northern Mexican Plateau; however they are larger, have shorter tails and yellow backs. Its skull is relatively narrow with a large braincase and they have heavy, thick teeth. Perote ground squirrels have two annual cycles, an active phase (March–November) and a hibernation phase (December–February). Some overlap may occur in March and November however.
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.
Citellina is a genus of nematodes within the Oxyuridae family. Species of this genus typically parasitise marmots and ground squirrels of holarctic distribution. It was initially defined by Prendel in 1928, with the type species Citellina dispar
Otospermophilus is a genus of ground squirrels in the family Sciuridae, containing three species from Mexico and the United States. Otospermophilus was formerly placed in the large ground squirrel genus Spermophilus, as a subgenus or species group. Since DNA sequencing of the cytochrome b gene has shown Spermophilus to be paraphyletic to the prairie dogs and marmots, it is now separated, along with six other genera.
Notocitellus is a genus of ground squirrels, containing two species from Mexico. These species are the tropical ground squirrel, and the ring-tailed ground squirrel (N. annulatus). Notocitellus was formerly placed in the large ground squirrel genus Spermophilus, as a subgenus or species group. Since DNA sequencing of the cytochrome b gene has shown Spermophilus to be paraphyletic to the marmots, antelope squirrels, and prairie dogs, it is now separated, along with six other genera. The exact relations of this genus are unclear, though a relation to the antelope squirrels is possible.
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.
Ictidomys is a North American genus of rodent in the squirrel family, which contains the thirteen-lined ground squirrel, the Mexican ground squirrel, and the Rio Grande ground squirrel. These species were included in the species-rich ground squirrel genus Spermophilus until molecular data showed that this genus was not a natural, monophyletic grouping.
The Rio Grande ground squirrel is a species of squirrel in the family Sciuridae. It is found in the south-western United States and in north-eastern Mexico.