50.

Tian Shan Red-backed Vole

Myodes centralis

French: Campagnol dAsie centrale / German: Tienschan-Rotelmaus / Spanish: Topillo rojo de Tian Shan

Other common names: Tian Shan Gray Red-backed Vole

Taxonomy. Evotomys centralis G. S. Miller, 1906, “Koksu Valley, altitude 9000 feet [= 2743 km |,” western Tian Shan Mountains, Kazakhstan.

In the past, centralis was included in Fvotomys or Clethrionomys; both generic names are junior synonyms of Myodes . Some authors synonymized centralis with glareolus or rutilus . Molecular evidence showed that centralis is phylogenetically closer to glareolus . Two subspecies of centralis were classified as distinct species in the past; Chinese authors continue to treat them this way. Two subspecies recognized.

Subspecies and Distribution.

M.c.centralisG.S.Miller,1906—SEKazakhstanandNWXinjiang(China).

M. c. frater Thomas, 1908 — Kyrgyzstan and NW Xinjiang (China).

Descriptive notes. Head-body 104-115 mm (males) and 104-120 mm (females), tail 41-52 mm (males) and 50-56 mm (females); weight 24-33-5 g (males) and 28-5-33 g (females). Sexes are about the same size. The Tian Shan Red-backed Vole is similar in appearance to the Bank Vole ( M. glareolus), but pelage is less rusty. Back is ocherous buff to rich brown, and belly is light smoke gray. Darker juvenile pelage is replaced with adult pelage at body weights of 17-18 g. Tail is sharply bicolored. Skull is of same size and proportions as in the Bank Vole. Unlike in other red-backed voles, the Tian Shan Red-backed Vole has longer roots of upper incisors that stretch posteriorly close to roots of M'.

Habitat. Forests at elevations of 1300-3500 m, exceptionally at lower elevations. Majority of the distribution of the Tian Shan Red-backed Vole coincides with fir ( Abies, Pinaceae) forests and preferred habitats have shrubs, rocks, and dead wood.

Food and Feeding. Diets of Tian Shan Red-backed Voles mainly contain green plants; seeds and fruits are next in importance; and mushrooms and insects are rarely consumed. Preferred plants are willowherbs ( Epilobium, Onagraceae); Siberian clematis ( Clematis sibirica, Ranunculaceae); Alpine bells (Cortusa matthioli, Primulaceae); various species of Mulgedium and goldenrod ( Solidago virga-aurea), both Asteraceae; gentian ( Gentiana, Gentianaceae); geranium ( Geranium, Geraniaceae); raspberry ( Rubus idaeus), hawthorn ( Crataegus tianschanica), and rowan ( Sorbus tianschanica), all Rosaceae; and berries of barberry ( Berberis, Berberidaceae).

Breeding. Breeding season of the Tian Shan Red-backed Vole lasts c.7 months from early March to late September—early October at lower elevations and 4-4-5 months from early May to late August—early September in northern parts of its distribution. Females have up to three litters each breeding season; only two litters are born if spring starts late. Numbers of embryos are 2-9/litter. Adult females have litters averaging 4-4-5-3 young, depending on year, season, and location. Resorption of embryos was rarely observed. Young males are sexually mature at 2-2-5 months old and females at more than one month old. Both sexes participate in reproduction during their first year oflife. Young females are only 5-10% ofthe reproductive population, and they have a low number of embryos (mean 3-6). Young weigh c.1-5 g at birth, 2-1-2-8 g at day three, and c.7-5 g at two weeks. Eyes and ears open at 11-12 days of age, and young start eating solid food on day 15.

Activity patterns. The Tian Shan Red-backed Vole is mainly nocturnal and crepuscular, rarely diurnal. Two peaks of activity were recorded in August: 22:00 h and 05:00-07:00 h. Nests chamberis frequently inside a decaying fir tree ( Abies, Pinaceae), under roots or rocks, or in soil 25-30 cm below the surface and at least 30-35 cm from the entrance. Nest is woven from plant material (leaves, steams, and mosses), hairs, and feathers, and is 25-30 cm in diameter. Winter nests are constructed under thick snow, frequently close to a tree trunk.

Movements, Home range and Social organization. When feeding, Tian Shan Redbacked Voles rarely move more than 3 m from entrances to their burrows.

Status and Conservation. Classified as [Least Concern on The IUCN Red Last.

Bibliography. Fedosenko (2016), Gromov & Erbajeva (1995), Luo Zexun et al. (2000), Shenbrot & Krasnov (2005), Sludskiy et al. (1978).