114.

Maximowicz’s Vole

Alexandromys maximowiczii

French: Campagnol de Maximowicz / German: Maxomowicz-Wiihimaus / Spanish: Topillo de Maximowicz

Taxonomy. Arvicola maximowiczii Schrenck, 1859, mouth of Omutnaya River, upper Amur Region, Chita Oblast, Russia.

Alexandromys maximowiczii is in subgenus Alexandromys and maximowiczii species group. Morphologically and genetically, it 1s sister species to the A. evoronensis + A. mujanensis clade. Within A. maximowiczi1, there are two distinct mtDNA clades: western (Buryatia and south-western part of Zabaykalsky Krai) and eastern (middle part of Amur River Basin). Two subspecies recognized.

Subspecies and Distribution.

A.m.maximowiczuSchrenck,1859—SESiberia(SEZabaykalskyKrai),RussianFarEast(A.m.Region,YevreyskayaAutonomousOblast,KhabarovskKrai,andPrimorskyKrai),EMongolia,andNEChina(InnerMongolia[=NeiMongol],Heilongjiang,Jilin,Hebei,andShaanxi).

A. m. ungurensis Kastschenko, 1913 —S Siberia (S & E Buryatia and SW Zabaykalsky Krai in Russia) and N Mongolia.

Descriptive notes. Head-body 114-152 mm, tail 28-57 mm, ear 13-15 mm, hindfoot 18-22 mm; weight 25-95 g. Male Maximowicz’s Voles are larger than females. Fur color of head and upperparts is dark brown, underparts are dark gray, and tail is fuzzy bicolored. Sole of foot has five plantar pads. M? has 3-5 (usually four) inner and 2-5 (usually 3-4) outer angles. Baculum is relatively small (3:9-5-5 mm); its base is wide, with rounded proximal edge (base width is 1-5-2-3 mm) and short median (1-1-7 mm) and lateral (0-8-1 mm) processes. Chromosomal complement has 2n = 36-44 and FN = 54-58.

Habitat. Boreal coniferous forest, broad-leaf forest, and forest-steppe zones. Maximowicz’s Vole inhabits swampy forests and coastal wet meadows with tall grass stand and shrubs.

Food and Feeding. In summer, Maximowicz’s Vole eats mainly green parts of grasses, sedges, forbs, leaves of trees, and, to a lesser extent, insects (mainly grasshoppers). In winter and spring, it mainly eats roots, bulbs, and acorns. It stores food for winter in caches within burrows; winter caches are usually 5-10 kg/family group, sometimes up to 16 kg.

Breeding. Breeding of wild Maximowicz’s Vole was recorded in April-September. Litters have 1-16 young (averages 4-2-8-7), and intervals between pregnancies are 17-150 days (average 31-9). Females can have 3 litters/year. Gestation lasts 17-20 days. Females born in the first half of summer reach reproductive maturity at 35-40 days old; those born at the end of summer mature the following spring.

Activity patterns. Maximowicz’s Voles are active round-the-clock, but they are particularly active in early morning and late evening.

Movements, Home range and Social organization. Home ranges are 100-800 m? (average 370 m®) for subadults, 200-900 m? (average 500 m?) for adult females, and 500-1400 m* (average 960 m®) for adult males. During estrus, home ranges of females increase to 400-2400 m* (average 1050 m?). Home range is organized around a complex burrow. In wet habitats, burrows of Maximowicz’s Voles are inside earth mounds up to 100 cm in diameter and 15-20 cm high. In drier habitats, burrows are excavated under shrubs on slopes of shallow depressions. Each burrow has a nest chamber (35-38 cm in diameter) and 1-2 storage chambers connected by tunnels. Maximowicz’s Voles can also build aboveground nests inside dense shrubs. Burrows are connected to foraging sites by pathways, each path 5-10 m in length. Contacts among individuals are accompanied by acoustic communication expressed in quiet or sharp squeals and songs.

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

Bibliography. Abramson & Lissovsky (2012), Bannikov (1954), Gromov & Erbajeva (1995), Haring et al. (2011), Kartavtseva et al. (2008), Lissovsky & Obolenskaya (2011), Meyer et al. (1996), Rutovskaya (2015), Sheremetyeva, Kartavtseva, Frisman et al. (2015), Sheremetyeva, Kartavtseva, Voyta et al. (2009), Shvetsov et al. (1984), Zhang Yongzu et al. (1997).