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Steppe Vole

Lagurus lagurus

French: Campagnol des steppes / German: Steppenlemming / Spanish: Topillo de estepa

Other common names: Steppe Lemming

Taxonomy. Mus lagurus Pallas, 1773, mouth of Ural River, Indersk District, Atyrau Region, Kazakhstan.

Five subspecies are recognized.

Subspecies and Distribution.

L.l.lagurusPallas,1773—SEuropeanRussia,plainsofKazakhstan,andSWSiberiaWoftheObRiver.

L.l.abacanicusSerebrennikov,1929—SCSiberia(MinusinskDepressioninKhakassiaandSKrasnoyarskKrai).

L.l.agressusSerebrennikov,1929—C&SEEuropeanRussia(fromRyazan,Lipetsk,andVoronezhEtoBashkortostan).

L.l.altorumThomas,1912—severalsmallisolatedpopulationsinEKazakhstan,NWChina(NXinjiang),andSRussia(STuva),includingTarbagataiMts,DzungarianAlatau,TianShan,UvsNuurDepression,BaytagBogdUul,andMongolianAltai.

L. l. occidentalis Migulin, 1938 — Ukraine and S European Russia between Dnieper and Don rivers.

Descriptive notes. Head-body 73-125 mm, tail 6-16 mm, ear 5-7 mm, hindfoot 11-16 mm; weight 17-46 g. Male Steppe Voles are slightly larger than females. Fur color of head and upperparts varies from dark brown to light pale-gray; head and back have longitudinal dark strip; underparts are light whitish gray, with coating of yellow; and tail is uniformly light whitish, with long terminal brush of hairs. There are four plantar pads. Auditory bullae are large and inflated. M* has four inner and three outer angles. M| has seven isolated dentine areas on masticatory surface; anterior loop with additional angles on lingual and labial sidesis isolated from paraconid. Chromosomal complement has 2n = 54 and FN = 60.

Habitat. Steppes, semi-deserts, and mountain meadows at elevations up to 3000 m. In western part of its distribution, the Steppe Vole also occurs in open areas of foreststeppe; in the south, it penetrates desert. In forest steppe and steppe,it prefers dry areas with sparse grass-forb or grass-sagebrush ( Artemisia, Asteraceae) vegetation and avoids shrubs and dense Stipa (Poaceae) stands. In semi-deserts and deserts of Kazakhstan, it prefers relatively wet depressions with abundant green grass. In semi-desert of Tuva and north-western Mongolia (Uvs-Nuur Depression), it prefers Nanophyton-Salsola (both Amaranthaceae)-Artemisia associations. In agricultural landscape, it prefers abandoned fields but often inhabits edges of crop fields.

Food and Feeding. The Steppe Vole feeds mainly on green plant parts. Local lists of forage plants include 90-100 species. Although not selective, it prefers most juicy plants. It also eats seeds, roots, bulbs, and insects but usually in small amounts. Food is usually not stored; winter food stores were recorded in only western Kazakhstan.

Breeding. Breeding of Steppe Voles occurs mainly in March-September, but some females also have litters in winter. Litters have 1-14 young (averages 6-4-8-9). During reproductive season, overwintered females can produce 3-4 litters. Gestation lasts 19-23 days. Females can reach sexual maturity at 13-35 days old (usually 30) and can produce 2-3 litters in their first year.

Activity patterns. Steppe Voles are active round-the-clock, but activity patterns change seasonally. In late autumn, winter, and early spring, activity is mainly diurnal, but in summer,it is nocturnal and crepuscular.

Movements, Home range and Social organization. Steppe Voles live in monogamous family groups. At the beginning of the breeding season, the family group is usually composed of one male and one female. Later, family group also includes yearlings from 1-2 generations. Some yearlings remain in parental family groups until spring of the next year, but they do not breed due to behavioral mechanisms of inbreeding avoidance. Each family group occupies a single burrow with area c.0-25 ha around it; adult males aggressively defend their family burrow from strange males. All individuals in a group are amicable, share common nest, and participate in rearing young. Contacts among individuals from different family groups are usually aggressive. Burrow has a nest chamber (10-20 cm in diameter) at depths of 20-40 cm and 5-10 entrances that spread over surface areas of 1-5-8 m?; total lengths of tunnels are 3-28 m. Contacts among individuals include acoustic communication with quiet and sharp squeals. Quiet squeals are emitted by females during amicable and sexual contacts; sharp squeals are emitted by individuals of both sexes during aggressive contacts.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Populations of Steppe Voles are typified by large increases, often accompanied by mass migrations, and then long deep population declines. Subspecies occidentalis became extinct in Ukraine to the west of Dnieper River (Kiev and Odessa regions) at the beginning of 20™ century and to the east of Dnieper River (Poltava, Dnipropetrovsk and Zaporizhia regions) in the mid-20" century.

Bibliography. Abramson & Lissovsky (2012), Bannikov (1954), Gebczynska (1967), Gromov (2008), Gromov & Erbajeva (1995), Ognev (1950), Popov (1960), Potapov et al. (2012), Rutovskaya (2015), Sludskiy et al. (1978), Yudin et al. (1979), Zagorodnyuk (2009b), Zhang Yongzu et al. (1997).