Rock squirrel

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Rock squirrel
Spermophilus variegatus.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Sciuridae
Genus: Otospermophilus
Species:
O. variegatus
Binomial name
Otospermophilus variegatus
(Erxleben, 1777)
Synonyms

Spermophilus variegatus

The rock squirrel (Otospermophilus variegatus) 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. [2]

Contents

Characteristics

Rock squirrels are one of the largest members of the family Sciuridae, with adults measuring up to 21 inches (53 cm) in length. [3] In front and on top, the squirrel's coat is a speckled grayish brown; on the rear and bottom, the gray becomes a more mottled brownish-black tone. They have a marked light-colored ring around their eyes and pointed ears that project well above their heads. Rock squirrels have a long, bushy tail with white edges.

Life history/behavior

The female rock squirrel has two litters a year, with three to nine young in each litter. The first litter is typically born from April to June, while the second is born in August or September. They are active in the early morning and late afternoons when the weather is warm; when very hot, they may estivate. They are social, and live in colonies with several females and one dominant male that fights other mature males to protect the group. Subordinate males lurk at the outer boundaries of the group. Rock squirrels dig burrows with their sharp claws and muscular legs. The burrows provide shelter, safety, living space, and food storage. Burrow systems can be complex and lengthy, as they are enlarged over a period of years. Entrances are usually hidden beneath rocks and can be wider than 3 inches. In the northern reach of their habitat, rock squirrels hibernate during the colder months of the year. In southern areas, rock squirrels may not hibernate at all. [4] They can withstand long periods of time without water, some even up to 100 days. [5] When alarmed, they whistle a short, sharp, oscillating call.

Diet

The rock squirrel is predominantly a herbivore, eating mostly leaves, stems, and seeds, and occasionally invertebrates and small vertebrates. They also eat acorns, pine nuts, fruits of native plants, assorted grasses, mesquite, juniper berries, agaves and cacti. The primary invertebrates include grasshoppers, beetles and earthworms and the vertebrates include young wild turkeys and other fowl. [6] The rock squirrel may eat their own kind, scavenging the remains of squirrels that are already dead. Its diet changes with the seasons, accustoming itself to what is available locally. [7]

Rock squirrels forage for their food on a daily basis, by climbing trees and bushes or on the ground. They collect generous amounts of food items in their cheek pouches, which are quite large. One researcher counted 62 Gambel's oak acorns carried in one squirrel's pouch. [6] These foraging trips are generally short-lived, usually only lasting about 12 minutes. Most foraging is done in the morning, to avoid the hotter parts of the day. They eat some of the food right away and bring a significant portion back to a lookout point or burrow, where they can safely consume or store the rest. [8]

Predators

A variety of snakes, birds of prey, and other mammals (bobcats, ringtails, gray foxes, raccoons, coyotes, badgers, domestic cats and dogs) prey upon the rock squirrel. Humans have also been known to eat rock squirrels, but can also view them as pests, resulting in lethal and nonlethal removal. The rock squirrel displays a variety of antipredator behaviors. When close to a snake, they make menacing movements and even throw debris at the snake. They often feed, rest, and sunbathe in trees, high rocks, and stumps. This allows them to watch for predators and to communicate alarm calls to other squirrels. They also emit musky scent from their anal glands when disturbed by predators. [2]

A Rock Squirrel in its natural environment along the Verde River in Arizona. A Rock Squirrel in it's environment along the Verde River in Arizona.jpg
A Rock Squirrel in its natural environment along the Verde River in Arizona.

Geographic Range

Because of their specialized habitat requirements, there's very select states in the US where these creatures can sustain themselves. These squirrels inhabit rocky mountains, canyon walls, cliffs, and steep rocky hills and there's only a few areas within North America with such type of landscape. These squirrels can be found throughout the southern US border along with Mexico in states like California, Arizona, Utah, Colorado, Oklahoma, New Mexico and parts of West Texas.[ citation needed ] Contrary to popular belief, in Mexico these squirrels are not found in eastern coastal lowlands, but they inhabit areas of Jalisco, Guerrero, Mexico, Morelos, Colima and Puebla. In the western edge of the range of these squirrels in the US, they mostly inhabit parts of southeasternmost corners of California, which includes some of the most arid areas in the entire state.

Related Research Articles

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<span class="mw-page-title-main">California ground squirrel</span> Species of rodent

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.

<span class="mw-page-title-main">Ground squirrel</span> Type of ground-dwelling rodent

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.

<span class="mw-page-title-main">Franklin's ground squirrel</span> Species of rodent

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.

<span class="mw-page-title-main">Richardson's ground squirrel</span> Species of rodent

Richardson's ground squirrel, 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.

<span class="mw-page-title-main">Mohave ground squirrel</span> Species of rodent

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.

<span class="mw-page-title-main">European ground squirrel</span> Species of rodent

The European ground squirrel, also known as the European souslik, is a species from the squirrel family, Sciuridae. It is among the few European species in the genus Spermophilus. Like all squirrels, it is a member of the rodent order. It is to be found in eastern and central Europe from southern Ukraine, to Asia Minor, Austria, the Czech Republic, Slovakia, Serbia, Greece, Romania, Bulgaria, North Macedonia and north as far as Poland but the range is divided in two parts by the Carpathian Mountains.

<span class="mw-page-title-main">Arctic ground squirrel</span> Species of rodent

The Arctic ground squirrel 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.

<span class="mw-page-title-main">Belding's ground squirrel</span> Species of rodent

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.

<span class="mw-page-title-main">Thirteen-lined ground squirrel</span> Species of rodent

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.

<span class="mw-page-title-main">Round-tailed ground squirrel</span> Species of rodent

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.

<span class="mw-page-title-main">Tropical ground squirrel</span> Species of rodent

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.

<span class="mw-page-title-main">Red-cheeked ground squirrel</span> Species of rodent

The red-cheeked ground squirrel is a species of rodent in the family Sciuridae. It is commonly referred to as the red-cheeked ground souslik and there are several recognized subspecies. It is found in central Asia. Spermophilus brunnescens, Spermophilus heptneri and Spermophilus ungae are accepted as synonyms. There is some controversy over whether Spermophilus pallidicauda and Spermophilus brevicauda should be regarded as synonyms or full species.

<span class="mw-page-title-main">Mexican ground squirrel</span> Species of rodent

The Mexican ground squirrel is a species of rodent in the family Sciuridae. It is found in Mexico and the United States. One of its closest relatives is the thirteen-lined ground squirrel.

<span class="mw-page-title-main">Little ground squirrel</span> Species of rodent

The little ground squirrel or little souslik, is a species of rodent in the family Sciuridae. It is found from Eastern Europe to Central Asia.

<span class="mw-page-title-main">Cascade golden-mantled ground squirrel</span> Species of rodent

The Cascade golden-mantled ground squirrel is a species of rodent in the family Sciuridae, in the order Rodentia. It is the largest species of the three within the genus Callospermophilus. It is found in the Cascade Mountains in the province of British Columbia, Canada and the state of Washington, United States.

<span class="mw-page-title-main">Spotted ground squirrel</span> Species of 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.

<i>Otospermophilus</i> Genus of rodents

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.

References

  1. Lacher, T.; Timm, R.; Álvarez-Castañeda, S.T. (2016). "Otospermophilus variegatus". IUCN Red List of Threatened Species . 2016: e.T20495A22263993. doi: 10.2305/IUCN.UK.2016-3.RLTS.T20495A22263993.en . Retrieved 12 November 2021.
  2. 1 2 Langstaff, Lucas. ""Spermophilus variegatus rock squirrel"". nhpbs.org. Retrieved 2019-10-11.
  3. Helgen, Kristofer M.; Cole, F. Russel; Helgen, Lauren E. & Wilson, Don E (2009). "Generic revision in the Holarctic ground squirrel genus Spermophilus". Journal of Mammalogy. 90 (2): 270–305. doi: 10.1644/07-MAMM-A-309.1 . S2CID   28483038.
  4. Marsh 1994, p. B-153.
  5. Oaks et al. 1987, p. 6.
  6. 1 2 Langstaff, Lucas. "Spermophilus variegatus (rock squirrel)". Animal Diversity Web. Retrieved 2019-10-11.
  7. "Rock Squirrel - Spermophilus variegatus". Nature Works.
  8. "ADW: Spermophilus variegatus: INFORMATION". Animal Diversity Web.

Sources

Further reading