Xerospermophilus mohavensis (Merriam, 1889)
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publication ID |
https://doi.org/ 10.5281/zenodo.6840226 |
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DOI |
https://doi.org/10.5281/zenodo.6818994 |
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persistent identifier |
https://treatment.plazi.org/id/064D0660-FFAB-ED56-FF10-FEFEFD3AFD6B |
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treatment provided by |
Diego |
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scientific name |
Xerospermophilus mohavensis |
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Mohave Ground Squirrel
Xerospermophilus mohavensis View in CoL
French: Spermophile du Mohave / German: Mojave-Ziesel / Spanish: Ardilla terreste de Mojave
Other common names: Mojave Ground Squirrel
Taxonomy. Spermophilus mohavensis Merriam, 1889 View in CoL , “Mohave River, California.” Restricted by J. Grinnell and J. Dixon in 1918 to near Rabbit Springs, about 24 km east of Hesperia, San Bernardino County.
This species is monotypic.
Distribution. NW Mohave Desert and Owens Valley of S California (USA).
Descriptive notes. Head-body 210-230 mm,tail 57-72 mm; weight 70-300 g. The Mohave Ground Squirrel is smallbodied and has light brown to pale drab gray dorsal pelage, nearly uniform in color, with conspicuous absence of spots, flecking, or stripes. Head frequently has suffusion of rust or cinnamon. Venter is white to pale buff. Feet are pale buffto cinnamon. Tail is short but broad and rufous on top, frosted with white to pale buff, and white to cream underneath. Chromosomal complement is 2n = 38 and FN = 70.
Habitat. Deserts with abundant annual herbaceous vegetation on sandy or gravelly friable soils. Creosote bush (Larrea, Zygophylaceae) associations are a favored component in these habitats.
Food and Feeding. The Mohave Ground Squirrel is opportunistically omnivorous and feeds primarily on shoots,leaves, flowers, and seeds of grasses, forbs, shrubs, which are often collected in cheek pouches and consumed while vigilant on a promontory. The Mohave Ground Squirrel also consumes insects and other animal matter in significant amounts.
Breeding. The Mohave Ground Squirrel inhabits burrows that are often convoluted and contain a nest chamber in which young are born. Males emerge c.2 weeks before females and establish home ranges. Soon after females emerge, mating occurs in burrows, usually in February-March. After a gestation of 29-30 days,litters of 4-9 young are born, most often in late March or early April. Reproduction does not occurin years of drought.
Activity patterns. The Mohave Ground Squirrel is diurnal and hibernates for c.6 months in modestly complex burrow systems. It is active aboveground beginning in early to mid-spring, usually March—May for males and 2-4 weeks later for females. Immergence begins in August.
Movements, Home range and Social organization. The Mohave Ground Squirrel can live in very low densities (c.l ind/ha) and appears to be solitary. Loosely structured colonies can occur in high-quality habitat, and aggressive chases do occur. Burrows are often located at edges of home ranges; multiple burrows are used for escape cover, hibernation, or rearing young. Male mean home ranges (6-7 ha) are much larger than those of females (0-73 ha). Juveniles disperse as far as 6-2 km and appear to recolonize areas, with males (mean distance 1-5 km) moving farther than females (mean distance 0-5 km). Individuals are extremely docile and tolerate approach by humans. Mohave Ground Squirrels will use escape burrows for short-term cover but also lie on the ground and remain motionless. Alarm call is distinct high-pitched raspy peep.
Status and Conservation. Classified as Vulnerable on The IUCN Red List. Population trend of the Mohave Ground Squirrel is decreasing. Major conservation challenges are degradation of rangelands and fragmentation of habitats due to human development in a distribution that is restricted to 430,000 ha. Recent increases in and incentives for development of alternative renewable energy sources provide another future complication for conservation. It was historically viewed as a pest that was shot, trapped, or poisoned. Drought is a serious challenge because Mohave Ground Squirrels depend heavily on annual plants and reproductive failure occurs during dry years. A closely related species, the Round-tailed Ground Squirrel (X. tereticaudus), has been expanding its distribution and may become sympatric with the Mohave Ground Squirrel in the future.
Bibliography. Best (1995i), Brooks & Matchett (2002), Chornesky et al. (2015), Grinnell & Dixon (1918), Hafner (1992), Hafner & Yates (1983), Harris & Leitner (2004, 2005), Inman et al. (2013), Laabs (1998), Leitner (2015), Thorington et al. (2012), Zembal & Gall (1980).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
