The Mohave ground squirrel (''Xerospermophilus mohavensis'') is a species of

ground squirrel 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 ...

found only in the

Mojave Desert The Mojave Desert ( ; mov, Hayikwiir Mat'aar; es, Desierto de Mojave) is a desert in the rain shadow of the Sierra Nevada mountains in the Southwestern United States. It is named for the indigenous Mojave people. It is located primarily ...

in California. The squirrel was first described in 1886 by Frank Stephens of San Diego. It is listed as a

threatened Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensa ...

species under the California Endangered Species Act, but not under the federal Endangered Species Act. The IUCN lists this species as near threatened.

Description

The Mohave ground squirrel measures about nine inches from nose to tail and feeds on leaves and seeds from February to July. Near the end of July, the squirrels begin a period of

estivation Aestivation ( la, aestas (summer); also spelled estivation in American English) is a state of animal dormancy, similar to hibernation, although taking place in the summer rather than the winter. Aestivation is characterized by inactivity and a ...

, but this may occur as early as April in drought years. Populations generally do not reproduce following winters with less than 80mm of precipitation. Local populations can be wiped out if a drought lasts for multiple years.

Habitat and diet

This squirrel inhabits the western Mojave Desert in portions of Inyo, Kern, Los Angeles, and San Bernardino counties. It can occupy Joshua tree woodlands, creosote scrub, saltbush scrub and mojave mixed woody scrub. Typical forage plants are those that meet nutritional and water content requirements. These can include shrubs such as

winterfat ''Krascheninnikovia'' is a genus of flowering plants in the subfamily Chenopodioideae of the family Amaranthaceae known as winterfat, so-called because it is a nutritious livestock forage. They are known from Eurasia and western North America. Th ...

, spiny hopsage, and boxthorn ('' Lycium'' spp.). Preferred annuals include ''

Coreopsis ''Coreopsis'' () is a genus of flowering plants in the family Asteraceae. Common names include calliopsis and tickseed, a name shared with various other plants. Description These plants range from in height. The flowers are usually yellow wi ...

'' spp., '' Eremalche'' spp., ''

Astragalus ''Astragalus'' is a large genus of over 3,000 species of herbs and small shrubs, belonging to the legume family Fabaceae and the subfamily Faboideae. It is the largest genus of plants in terms of described species. The genus is native to tempe ...

'' spp., and lupine. Soils are usually friable and conducive to burrow excavation. Areas of preferred habitat include habitat types that provide ample forage to allow Mohave ground squirrels to persist during drought periods. These persistent populations may act as core areas from which populations expand from during adequate rainfall years which are required for Mohave ground squirrels to reproduce. This dynamic expansion and contraction in populations can make it challenging to determine whether the species is present since extended periods of drought can cause a die-off on local populations until surrounding populations expand during consecutive reproductive years.

Behavior

Mohave ground squirrels emit a high-pitched "peep" as an alarm call, when startled or when young begin to emerge from their natal burrows. The vocalization is sometimes confused with that of the

horned lark The horned lark or shore lark (''Eremophila alpestris'') is a species of lark in the family Alaudidae found across the northern hemisphere. It is known as "horned lark" in North America and "shore lark" in Europe. Taxonomy, evolution and systema ...

, and, in areas where the two species are sympatric, with round-tailed ground squirrels. Mohave ground squirrels can occasionally be sighted perched in ''Lycium cooperii'' or in Creosote bush (''Larrea tridentata'') during mid-morning (9-11 a.m.) hours (April–June) basking in the sun. Males emerge from hibernation in early February and females are soon to follow. Reproduction occurs in early March and gestation lasts for about four weeks. Litters range from 4-6 individuals. Juveniles emerge from the natal burrows in late May to Mid June. Predators include badgers, coyotes, snakes, falcons and hawks.

References

* Best, T. L. 1995. ''Spermophilus mohavensis''. Mammalian Species 509:1-7. * CDFG Special Animals List, February 2008.

*

External links

{{Taxonbar, from=Q1769414 Xerospermophilus squirrel Fauna of the Mojave Desert Mammals described in 1889 Taxa named by Clinton Hart Merriam