112.

Evoron Vole

Alexandromys evoronensis

French: Campagnol de I'Evoron / German: Eworon-Wiihimaus / Spanish: Topillo de Evoron

Other common names: Evorsk Vole, Lake Evoron Vole

Taxonomy. Microtus evoronensis Kovalskaya & Sokolov, 1980, mouth of Devyatka River, Lake Evoron, Khabarovsk Krai, Russia.

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

Distribution. Restricted to three small isolated areas in the lower Amur River Basin of Russian Far East (Upper Bureya River Depression, Chukchagyr-Evoron lakes Depression, adjacent parts of Amgun River Valley, and Upper Zeya River Depression).

Descriptive notes. Head—body 122-157 mm, tail 40-65 mm, ear 11-15 mm, hindfoot 18-22 mm; weight 51-91 g. Male Evoron Voles are larger than females. Fur color of head and upperparts is dark brown, underparts vary from dark gray to whitish, and tail is bicolored. Sole of foot hasfive plantar pads. M? has 4-5 inner and 3-5 outer angles. Baculum is large (4-3-5-7 mm length); its base is wide but short, with acutely angled proximal edge (base widths 1-6-2-6 mm) and long median (1-5-2 mm) and relatively short lateral (0-65—1 mm) processes. Chromosomal complement has 2n = 38-40 and FN = 54-56.

Habitat. Riparian habitats of boreal coniferous forest zone. The Evoron Vole inhabits regularly flooded wet sedge and sedge-grass meadows in high-water river beds and shrub-peat moss and sedge-woodreed bogs.

Food and Feeding. The Evoron Vole mainly eats green parts of sedges and grasses, including woodreed (Camalagrostis) and mannagrass ( Glyceria), both Poaceae; burnet ( Sanguisorba, Rosaceae), and pondweed ( Potamogetonaceae).

Breeding. Breeding of wild Evoron Voles was recorded in May-July. Females can have up to 3 litters/year. Under laboratory conditions, breeding is intense, with litters of 3-11 young (average 5-7) and intervals between pregnancies of 18-42 days (average 23-4). Gestation lasts 17-20 days. Pregnancy often coincides with lactation.

Activity patterns. No information.

Movements, Home range and Social organization. Home range of Evoron Voles is organized around the nest, usually built under a hummock and connected to shelter burrows and foraging sites by pathways. Maximal length of pathway is 30 m.

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

Bibliography. Abramson & Lissovsky (2012), Gromov & Erbajeva (1995), Kostenko (1984), Lissovsky & Obolenskaya (2011), Meyer et al. (1996), Sheremetyeva, Kartavtseva & Vasiljeva (2017), Sheremetyeva, Kartavtseva, Vasiljeva & Frisman (2016).