Alexandromys mongolicus

117.

Mongolian Vole

Alexandromys mongolicus

French: Campagnol de Mongolie / German: Mongolische Wiihimaus / Spanish: Topillo de Mongolia

Taxonomy. Arvicola mongolicus Radde, 1861, Omutnaya River Valley, tributary to Amur River, Transbaikalia (Chitinskaya Oblast), Russia.

In the past, A. mongolicus was considered a well-differentiated subspecies of Microtus arvalis. It is now in subgenus Alexandromys and mongolicus species group. This species group is morphologically well defined within the subgenus, but mtDNA suggests close affinities to the A. middendorffii + A. gromovi clade. Some morphological differences exist among populations from western and eastern parts of the distribution. Monotypic.

Distribution. S Siberia (Altai Republic, S Krasnoyarsk Krai, Tuva, Buryatia, Zabaykalsky Krai, and Amur Region of Russia), N & E Mongolia, and NE China (Inner Mongolia [= Nei Mongol], Heilongjiang, and Jilin).

Descriptive notes. Head-body 81-123 mm, tail 21-39 mm, ear 7-15 mm, hindfoot 12-18 mm; weight 13-40 g. Fur color of head and upperparts is dark blackish brown, underparts are dark ash-gray, and tail is distinctly bicolored. Sole of foot has five plantar pads. M® has 3-4 (usually four) inner and 3-4 (usually three) outer angles. Baculum is medium-sized; its base is wide, with right-angle or rounded proximal edge. Median process is long, and lateral processes are short. Chromosomal complement has 2n = 50 and FN = 58.

Habitat. Riparian habitats in boreal coniferous forest, mixed forest, forest steppe, and steppe zones and mountain meadows up to elevations of ¢.3000 m. Main habitats of Mongolian Voles are wet tussock meadows.

Food and Feeding. The Mongolian Vole eats green and underground parts of plants. It stores food (bulbs and roots) for winter in caches in its burrow; winter caches are 1-2 kg/family group.

Breeding. Breeding of wild Mongolian Voles was recorded in May—August. Litters have 5-9 young (usually 6-7). Adult females have 2 litters/year.

Activity patterns. Summeractivity of Mongolian Voles in well-protected habitats with dense vegetation is round-the-clock, with a short interruption at midday. In open habitats, individuals are active at dusk and night.

Movements, Home range and Social organization. Mongolian Voleslive in family colonies. Home range of a colony contains 5-6 nest burrows. Within the colony, all nesting burrows, simple shelter tunnels, and foraging sites are connected by pathways; length of one pathway can be up to 10 m. Nesting burrows have 2-8 entrances, a nest chamber (20 cm in diameter and 15-30 cm deep), and 1-2 storing chambers.

Status and Conservation. Classified as Least Concern on The IUCN Red List (as Microtus mongolicus).

Bibliography. Abramson & Lissovsky (2012), Bannikov (1954), Bannikova et al. (2010), Gromov & Erbajeva (1995), Lissovsky & Obolenskaya (2011), Malygin (1983), Meyer et al. (1996), Shvetsov et al. (1984), Zhang Yongzu et al. (1997).