Spermophilopsis leptodactylus

Introduction

Spermophilopsis leptodactylus is the only species within the genus Spermophilopsis. Known as the Long-clawed ground squirrel, S. leptodactylus is a terrestrial squirrel, usually inhabiting sandy deserts in regions of Central Asia such as Afghanistan and Iran. This ground squirrel is social like most ground squirrel species, but tends to have smaller sized family groups compared to prairie dog (Cynomys) colonies. The small family unit will congregate in and around burrows that are near or hidden by brush and foliage. The squirrel’s diet ranges from fruits and seeds to green vegetation and insects. It has been observed to travel almost 1,000 meters in search of food when its food sources have diminished (Novak 1999).

S. leptodactylus is active during the day, and therefore easily observable by researchers. This species of squirrel does not hibernate and mating occurs annually in February and March, with two to six offspring being born around April or May (Krapp in Grzimek 1990; Novak 1999). The squirrel’s name comes from the unusually long claws on its forelimbs. No other squirrel has claws as long as S. leptodactylus. In 1996, the World Conservation Union put S. leptodactylus on their Red List of Threatened Species (Baillie 1996).

Characteristics

The Long-clawed Ground Squirrel is an average sized squirrel species, with a head and body length of 200-280 mm and tail length approximately 70-90 mm. The color of their coat is separated, with the dorsal side a yellow to grayish-yellow tint and the ventral, underside, white. There are no stripes evident on this species. The coat is very short in the summer and long and fuzzy in the winter. With this seasonal change in coat, the squirrel is active throughout the year. The bottom of the tail has a black tint and the top is fringed with yellow and white bristles. The soles of the feet are heavily furred year round (Krapp in Grzimek 1990).

A unique characteristic of S. leptodactylus is the multiple pairs of vibrissae on the underside of its body. Vibrissae are stiff hairs, similar to whiskers on cats, that are very sensitive to surrounding environments. The vibrissae on this squirrel may be helpful when it is climbing through shrubs.

The defining features of this species are the long, thick claws. Growing more than 10 mm long, these claws are very powerful and are used for multiple purposes, including digging burrows (Novak 1999).

Systematics

Originally, this species was described as Arctomys leptodactylus (Lichtenstein 1823). The genus Spermophilopsis was derived by Blasius (1884), and placed in the tribe Xerini by Moore (1959). Gromov et al. (1965) placed S. leptodactylus into the Subfamily Xerinae. Nadler and Hoffman (1974) found S. leptodactylus to be genetically related to the African xerine squirrels (Wilson and Reeder 2005). In 2004, Steppan et al. concluded that there were three major lineages within the ground squirrel clade known as the Xerine group. One major lineage, the Old World Xerini, includes S. leptodactylus, and places the species among the African Xerus  and Atlantoxerus species (Steppan et al. 2004).

Geographic Distribution

S. leptodactylus is the only species of the xerine squirrels found outside of Africa. The squirrel is concentrated in Central Asia, from the southeastern shore of the Caspian Sea to Lake Balkhash in Kazakhstan.  This includes the countries Turkmenistan, Uzbekistan and is limited to the western parts of Tajikistan. The northwest region of Afghanistan and northeast region of Iran create the southern most boundary of the squirrel’s distribution (Corbet 1978; Lay 1967; Wilson and Reeder 2005).

Other Names for Spermophilopsis leptodactylus

• Long-clawed Ground Squirrel
• Spermophilopsis
• Arctomys leptodactylus Lichtenstein 1823

References

Baillie, J. 1996. Spermophilopsis leptodactylus. In: IUCN 2006. 2006 IUCN Red List of Threatened Species. www.iucnredlist.org.

Corbet, G.B. 1978. The mammalsof the Palaearctic Region: a taxanomic review. British Mus. (Nat. Hist.), London.

Gromov et al. 1965. Fauna SSSR. Mlekopitayushchie, Volume 3, no. 2. Ground Squirrels (Marmotinae). Nauka, Moscow-Lenningrad.

Grzimek, B., ed. 1990. Grzimek’s encyclopedia of mammals. Mc-Graw-Hill, New York, vol 3.

Lay, D.M. 1967. A study of the mammals of Iran. Fieldiana Zool. 54:1-282.

Moore, J.C. 1959. Relationships among the living squirrels of the Sciurinae. Bulletin of the American Museum of Natural History.

Nadler, C.F., and R.S. Hoffmann. 1974. Chromosomes of the African ground squirrel, Xerus rutilus. Experientia, 30:889-890.

Nowak, N.M. Walker's Mammals of the World. 6th ed. Vol. 2. Baltimore, MD: Johns Hopkins UP, 1999.

Steppan, S. J., B. L. Storz, and R. S. Hoffmann. 2004. Nuclear DNA phylogeny of the squirrels (Mammalia: Rodentia) and the evolution of arboreality from c-myc and RAG1. Molecular Phylogenetics and Evolution.30:703-719.

Wilson, D. E., and D. M. Reeder (Eds.). 2005. Mammal Species of the World, Third Edition. Johns Hopkins UP, Baltimore, MD.