177.

East European Vole

Microtus mystacinus

French: Campagnol de De Filippi / German: Ostfeldmaus / Spanish: Topillo europeo oriental

Other common names: Russian Vole, Sibling Vole, Southern Vole

Taxonomy. Arvicola mystacinus De Filippi, 1865, Lar Valley, N Iran.

Microtus mystacinus is in subgenus Microtus and mystacinus species group. It was recognized in 1972 as a distinct species from M. arvalis and subsequently reported under five different names: subarvalis named by M. N. Meyer, V. N. Orlov and E. D. Skholl’ in 1972 (not subarvalis by E. Heller in 1933), epiroticus, rossiaemeridionalis, levis, and mystacinus . It was separated from arvalis based on chromosomal evidence (2n = 54 in mystacinus and 2n = 46 in arvalis) and cross-breeding experiments. The latter failed to produce litters between mystacinus and arvalis . Taxonomic status of mystacinus is also evident from nucleotide sequences. Subspecific taxonomy was never thoroughly assessed. Monotypic.

Distribution. N & E Europe (S Finland, Baltic states, Belarus, Ukraine, Moldova, and W & SW Russia), Balkans (E Romania, S Serbia, Macedonia, Bulgaria, and Greece), Turkey, Armenia, NW & N Iran, W & N Kazakhstan, and Russia as far E as Tobol River in W Siberia. Introduced to Svalbard and Jan Mayen Is in the N Atlantic and to several scattered localities in Siberia, Olkhon I in Lake Baikal, and Khabarovsk Krai in Russian Far East.

Descriptive notes. Head—body 102-130 mm, tail 33-55 mm; weight 21-58 g. Males are, on average, heavier than females; means for 90day-old individuals are 30-5 g for males and 25-6 g for females. Individuals are, on average, larger in the south than the north. The East European Vole is moderately large, with short, stout, and large head; blunt muzzle; moderately large eyes; and long ears that protrude above fur. Tail averages 37% of head-body length. Legs are short, with six (exceptionally five) plantar tubercles. Females have eight nipples, two pairs each of pectoral and inguinal. Fur is shaggy and moderately long. Back is dark brown, frequently shaded buff, grizzled with black tips of long hairs. Flanks are lighter and more yellowish, and demarcation along flanks is faint. Belly is gray and washed with white or buff. Skull is of characteristic Microtus shape. Zygomatic arches are moderately expanded, and their widths account for ¢.656% of skull length. Supraorbital ridges merge in adults to form a sagittal crest. Incisors are orthodont. Molars are essentially same as in other social species of Mircotus, but M* lacks postero-lingual loop. M? is complex, with up to four reentrant angles on inner and outer sides.

Habitat. Open habitats and arable land on various substrates, including sand, from sea level to elevations up to ¢.2480 m. East European Voles preferred sites with high and dense herbaceous or grassy vegetation, hedgerows, and stands of reeds. They are frequently encountered with wet meadows and marshes and avoid short-grass meadows and dry areas. They can occur in urban areas including large cities such as Moscow. East European Voles occasionally settle in sparse woodland and inside buildings (e.g. greenhouses, stables, and vegetable stores).

Food and Feeding. The East European Vole is more granivorous than the Common Vole ( M. arvalis) and considered an agricultural pest.

Breeding. In the Balkans, breeding season of the East European Vole starts in early April and lasts into October. Reproductively active females weigh 15-50 g, and ovulation is induced. In captivity, gestation lasts 18-22 days. Numbers of embryos are 2-10/ female, and mean is 4-3 in Anatolia (Turkey) and 5-6 in the Balkans. Averagelitter in captivity is 4-6 young. Multiparous females have larger litters (5-9) than primiparous females (3-6). Females show postpartum estrus on the day of parturition, and interpartum times are 19-27 days. Young are born nude, blind, and with sealed ears. At birth, young weigh 1:4-3-2 g (mean 2-3 g), and at weaning (20 days old), they weigh 10-9-25-6 g (mean 18-7 g). Females are sexually mature at 45-60 days old (mean 54 days).

Activity patterns. Daily activity is polyphasic. East European Voles excavate extensive burrows, with numerous entrances and tunnels descending 20-25 cm. Each burrow system has at least one nest chamber that is usually situated at the deepest point. Complex systems go deeper (up to 30-35 cm) and have several nests. Entrances to burrows are connected by aboveground runways through vegetation. While exploring their habitat, East European Voles are less neophobic than Common Voles.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as [Least Concern on The IUCN Red List (as M. levis). Overall distribution of the East European Vole is ¢.3,800,000 km?.

Bibliography. Heller (1933), Krystufek & Vohralik (2005), Mahmoudi, Darvish, Aliabadian, Khosravi et al. (2014), Mahmoudi, Darvish, Aliabadian, Moghaddam & Krystufek (2017), Meyer, Golenishchev et al. (1996), Meyer, Orlov & Skholl’ (1972), Petrov & Ruzi¢ (1982), Shenbrot & Krasnov (2005), Tiunov et al. (2013), Widayati et al. (2003).