Ictidomys tridecemlineatus
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
Ictidomys
Ictidomys tridecemlineatus

description: 214. Thirteen-lined Ground Squirrel <i>Ictidomys tridecemlineatus</i> <b>French:</b> Spermophile rayé / <b>German:</b> Dreizehnstreifenziesel / <b>Spanish:</b> Ardilla terrestre de trece franjas <b>Taxonomy.</b> Sciurus tridecemlineatus Mitchill, 1821, near the source of the Mississippi River. Restricted by J. A. Allen in 1895 to central Minnesota, USA. Ten subspecies are recognized. <b>Subspecies and Distribution.</b> 1. t. tridecemlineatus Mitchill, 1821 — SC Canada and C USA. I.t.alleniMerriam,1898—WCWyoming(USA). I.t.arenicolaA.H.Howell,1928—EColorado,WKansas,WOklahoma,NENewMexico,andNWTexas(USA). I.t.blancaArmstrong,1971—SCColorado(USA). I. t. hollister: Bailey, 1913 — C New Mexico (USA). I.t.monticolaA.H.Howell,1928—ECArizonaandWCNewMexico(USA). Lt.olivaceusJ.A.Allen,1895—NEWyomingandWCSouthDakota(USA). ILt.pallidusJ.A.Allen,1874—NGreatPlains(USA). Lt.parvus].A.Allen,1895—SCWyoming,NEUtah,andNWColorado(USA). I. t. texensis Merriam, 1898 — SE Kansas, SW Missouri, Oklahoma, and C Texas (USA). <b>Descriptive notes.</b> Head-body 170-310 mm,tail 60-132 mm; weight 110-270 g. Dorsal pelage of the Thirteen-lined Ground Squirrel is very characteristic, with alternating light and dark longitudinal stripes. Five cinnamon to sepia to black dark stripes are usually evident, with series of white to buff spots or squares along middle of each stripe. Alternating with these dark stripes are six light cream to buff stripes that are sometimes broken into spots. Additional lines or spots can occur lower on the sides. Chin, cheeks, eye rings, and sides of nose are buff to cinnamon-buff. Ventral pelage ranges from buff to cinnamon-buff to pinkish buff, and tail is fuscous black on dorsal surface, suffused with brown and frosted with buff; on ventral side, tail is fuscous black throughout, with russet brown at base and cinnamon buff near tip. Subspecies alleni and blanca are small and pale. Subspecies arenicola is also small and pale, with light brownish dark stripes. Subspecies hollisteri has reddish tinge to dark stripes and strong buff tinge to light stripes. Subspecies monticola has reddish tinge to dorsum and underside oftail. Subspecies olivaceus is much darker on dorsum, with light stripes and pale yellowish olivaceous spots. Subspecies pallidus is another small and pale form. Subspecies parvus has two of the medial light dorsalstripes broken into spots. Subspecies texensis is smallish, with pale back and underside of tail, and reddish tinge. Chromosomal complement is 2n = 34 and FN = 64. Sex chromosomes consist of submetacentric X-chromosome and acrocentric Y-chromosome. <b>Habitat.</b> Dry and sandy soils of open and very short grasslands, meadows, and shrublands. The Thirteen-lined Ground Squirrel is very adaptable and also occurs in road verges, cultivated fields, airfields, golf courses, and suburban lawns. <b>Food and Feeding.</b> Dietis variable and more omnivorous than many other ground squirrel species. It consists of shoots, leaves, flowers, seeds, and fruits of grasses, forbs, and trees. Insects are also commonly eaten and sometimes even small vertebrates. Seed storage in the burrow for winter is common. <b>Breeding.</b> Mating of the Thirteen-lined Ground Squirrel occurs soon after females emerge from hibernation. Males defend breeding territories but also wander far beyond defended areas to find females. Male-male aggression is low because males queue while waiting to mate with female. Copulation most frequently occurs aboveground, and females mate with multiple males. Pregnancy lasts 27-28 days, and litters of 1-14 young (average eight), weighing c.3-2 g. each, are born in burrows. Juveniles emerge when they are c.5 weeks old and are weaned at 6-7 weeks old. Juveniles disperse from natal areas and reach adult size in c.11 weeks. Females reach sexual maturity at one year of age, and males at ¢.8 months. Only a single litter is produced per year, except some southern populations may breed a second time. <b>Activity patterns.</b> The Thirteen-lined Ground Squirrel is diurnal and terrestrial and hibernates for 5-8 months. Emergence from burrows begins in mid-March, with adult males emerging through April or sometimes May, and adult females emerging in May. Hibernation begins in late July, with adult males immerging first andjuveniles immerging later in about October, after accumulating considerable fat stores that enable them to reach sexual maturity by their first spring. <b>Movements, Home range and Social organization.</b> Although not very social, Thirteenlined Ground Squirrels tend to aggregate in areas of high-quality habitat. In some populations, territories are defended, while in others, there is a considerable home range overlap. Male home ranges (5 ha) are larger than those of females (0-5-0-8 ha), and individuals rub cheek glands on objects to scent-mark. It builds two types of burrows: simple, short and inconspicuous escape burrows used as a temporary shelter against possible threats and deep and complex nesting burrows that can be 8 m long and 0-5 m deep, with grass-lined nest chamber. Burrow entrance is plugged each night. Alarm call is described as soft whistled trill, usually given close to burrow entrance in response to terrestrial predators, but not aerial ones, and mainly by females with young, suggesting a main function warning to their progeny. <b>Status and Conservation.</b> Classified as Least Concern on The IUCN Red List. Subspecies monticola is of special concern in Arizona (USA). Current population trend of the Thirteen-lined Ground Squirrel is stable, and there are no major threats. It is common in manicured grass landscapes throughout much of its distribution and usually tolerated by humans due to low densities, small burrow structures, and intriguing appearance. Although not hunted,it is occasionally removed from some areas by trapping or poisoning. Status does not warrant conservation concern, and distribution includes several protected areas. <b>Bibliography.</b> Allen (1895), Arenz &amp; Leger (1999), Cothran (1983), Cothran &amp; Honeycutt (1984), Devenport et al. (2000), Hayssen et al. (1993), Luna &amp; Baird (2004), Schwagmeyer (1980), Schwagmeyer &amp; Woonter (1985), 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 pages 804-805, DOI: 10.5281/zenodo.6840226