113.

Muya Valley Vole

Alexandromys mujanensis

French: Campagnol de la Mouia / German: Burjatien-WihIimaus / Spanish: Topillo de Muya

Other common names: Muisk Vole

Taxonomy. Microtus mujanensis Orlov & Kovalskaya, 1978, Muja Valley, Vitim River Basin, Bauntovski District, Buryatia, Russia.

Alexandromys mujanensis is in subgenus Alexandromys and maximowiczii species group. Morphologically and genetically,it is sister species to A. evoronensis . Monotypic.

Distribution. Restricted to three small isolated areas of S Siberia (NE Buryatia and N Zabaykalsky Krai): N Barguzin River, Lake Baunt, and Lower Muya River hollows.

Descriptive notes. Head-body 110-158 mm, tail 34-58 mm, ear 12-16 mm, hindfoot 18-23 mm; weight 41-97 g. Male Muya Valley Voles are larger than females. Fur color of head and upperparts is dark brown, underparts are dirty gray, and tail is monochromatic. Sole of foot has five plantar pads. M? has 4-5 inner and 3-5 outer angles. Baculum is large (4-:3-5-9 mm long); its base is wide, with trapezoidal proximal edge (base widths 1-9-2-6 mm) and long median (1-5-2-3 mm) and lateral (0-9-1-6 mm) processes. Chromosomal complement has 2n = 38 and FN = 50-52.

Habitat. Riparian habitats of boreal coniferous forest zone. The Muya Valley Vole inhabits regularly flooded, wet sedge-grass, hummocky meadows with shrubs in highwaterriver beds.

Food and Feeding. The Muya Valley Vole feeds mainly on green parts of sedges and grasses, including bluegrass, mannagrass ( Glyceria) and woodreed (Camalagrostis), both Poaceae .

Breeding. Breeding of wild Muya Valley Voles was recorded in April-September. Litters have 3-12 young (averages 6-8-8-8), and intervals between pregnancies are 18-90 days (average 38-7). Females can have 2—4 litters/year. Gestation lasts 17-20 days.

Activity patterns. No information.

Movements, Home range and Social organization. Home range of the Muya Valley Vole is organized around a complex burrow, which is inside a ground mound 60-100 cm in diameter and up to 40 cm high, usually under a shrub or tree. Each burrow has 3-10 nest chambers, connected by tunnels. Burrows are connected to foraging sites by pathways.

Status and Conservation. Classified as Data Deficient on The IUCN Red List (as Microtus MuUjanensis).

Bibliography. Abramson & Lissovsky (2012), Borisova & Kartavtseva (2013), Golenishchev et al. (2015), Gromov & Erbajeva (1995), Lissovsky & Obolenskaya (2011), Meyer et al. (1996).