Xerospermophilus spilosoma
Creators: name: Wilson, Don E.
name: Thomas E. Lacher, Jr
name: Mittermeier, Russell A.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Sciuridae
Xerospermophilus
Xerospermophilus spilosoma

description: 221. Spotted Ground Squirrel <i>Xerospermophilus spilosoma</i> <b>French:</b> Spermophile moucheté / <b>German:</b> Fleckenziesel / <b>Spanish:</b> Ardilla terrestre moteada <b>Taxonomy.</b> Spermophilus spilosoma Bennett, 1833, “that part of California which adjoins to Mexico.” Restricted by A. H. Howell in 1938 to Durango City, Durango, Mexico. Thirteen subspecies are recognized. <b>Subspecies and Distribution.</b> X.s.spilosomaBennett,1833—DurangotoJaliscoandWGuanajuato(Mexico). X.s.altiplanensisS.Anderson,1972—HighplainsofWCChihuahua(Mexico). X.s.ammophilusHoffmeister,1959—ExtremeNChihuahua,inthesanddunesSofCiudadJuarez(Mexico). X.s.annectensMerriam,1893—STexasandtheRioGrandeValley(USA). X.s.bavicorensisS.Anderson,1972—BasinoftheLagunadeBabicorainWCChihuahua(Mexico). X.s.cabreraiDalquest,1951—SanLuisPotosiandvicinity,inCMexico. X.s.canescensMerriam,1890—SEArizona,andSCNewMexicothroughTexas(USA),intoNSonoraandCoahuila(Mexico). X.s.eryptospilotusMerriam,1890—FourCornersareaofSEUtah,SWColorado,NEArizona,andNWNewMexico(USA). X.s.marginatusBailey,1902—EColorado,WKansas,NewMexico,WTexas,andtheOklahomaPanhandle(USA). X.s.obsoletusKennicott,1863—extremeSSouthDakota,SEWyoming,WNebraska,NEColorado,andNWKansas(USA). X.s.oricolusAlvarez,1962—coastalTamaulipas,inNEMexico. X.s.pallescensA.H.Howell,1928—CentralHighlandsfromSEChihuahuatoNZacatecas,inCMexico. X. s. pratensis Merriam, 1890 — N Arizona (USA). <b>Descriptive notes.</b> Head-body 185-253 mm, tail 55-92 mm; weight 100-200 g. Dorsal pelage of the Spotted Ground Squirrel varies from gray, brown, and cinnamon to reddish, with scattered small white-to-buff spots of variable intensity. Ventral pelage varies from whitish, buff, and cinnamon or pinkish buff. Tail is similar in color to dorsum but with fuscous black toward tip and cinnamon core on underside. Subspecies altiplanensis has dark and yellowish dorsum. Subspecies ammophilus is extremely pale. Subspecies annectens exhibits no distinctive color but has slightly longer skull that is narrower at base and broader at interorbital region. Subspecies bavicorensis is large and has an unusually blackish pelage. Subspecies cabrerai is large, with darker dorsum. Subspecies canescens has reddish hue, with spots that are larger and more numerous on posterior dorsum; apex of tail is dark. Subspecies cryptospilotus is pale and reddish, with distinct small spotting on dorsum. Subspecies marginatus has reduced number of dorsal spots; dorsum is pale and gray, tinged with red. Subspecies obsoletus is drab and has less distinct and sometimes obsolete spots on dorsum. Subspecies oricolus is distinctly spotted, with near cinnamon-buff on hindfeet. Subspecies pallescens is darker on posterior dorsum, with finer spots. Subspecies pratensis is smallish and short-tailed, with darker dorsum and tip of tail. Chromosome numberis 2n = 32. <b>Habitat.</b> Deep sandy soils with sparse vegetation, such desert grasslands, desert scrub, heavily grazed pastures, sand dunes, and coastal plains. The Spotted Ground Squirrel also occurs in grassy urban parks, cemeteries, and schoolyards. <b>Food and Feeding.</b> Diet consists of leaves, shoots, flowers, and seeds of grasses, forbs, small shrubs, and cacti. Insects and small vertebrates are consumed when available. Overwinter food caches are not common. <b>Breeding.</b> Mating of the Spotted Ground Squirrel occurs when females appear from hibernation. After gestation of 28 days, females give birth in burrows to litters of 3-8 young. Young emerge at 3-4 weeks of age and are weaned c.3 weeks later. Adults are aggressive during the breeding season, but after it ends, they become more tolerant with conspecifics. Young reach sexual maturity at one year of age, and adult females appear to be able to produce two litters per year. <b>Activity patterns.</b> The Spotted Ground Squirrel is diurnal, spending most ofits active time aboveground foraging and feeding. Hibernation lasts 7-8 months, but individuals can stay active or have only short bouts of torpor during mild winters. Adult males usually immerge in July-August, followed closely by adult females, but juveniles often remain active until late September. Yearlings are the first to emerge, followed by older adult males, and then after 2-3 weeks, adult females. <b>Movements, Home range and Social organization.</b> Home range sizes are relatively large for males (1-4-9 ha) and females (0-5-1-5 ha). Burrow densities and populations are typically low, probably consequences of resource availabilities and low levels of sociality. Burrows seem to be relatively simple, c.1 m deep. <b>Status and Conservation.</b> Classified as Least Concern on The IUCN Red List. Current population trend of the Spotted Ground Squirrel is stable with no major threats. It is highly tolerant of habitat modification and appears to be at home in areas with deep sandy soils, sparse desert, or short grass vegetation and in heavily grazed habitats and grassy urban parks. Seldom hunted or trapped, but when a pest,it is shot or poisoned. <b>Bibliography.</b> Howell (1938), Livoreil &amp; Baudoin (1996), Livoreil et al. (1993), Mandier &amp; Gouat (1996), Millan-Pena (1998), Stangl &amp; Goetze (1991), Streubel &amp; Fitzgerald (1978), Thorington et al. (2012).
description: Published as part of <i>Don E. Wilson, Thomas E. Lacher, Jr &amp; Russell A. Mittermeier, 2016, Sciuridae, pp. 648-837 in Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona :Lynx Edicions</i> on page 809, DOI: 10.5281/zenodo.6840226