115.

Reed Vole

Alexandromys fortis

French: Campagnol des roseaux / German: Schilfwihlmaus / Spanish: Topillo de ribera

Other common names: Yangtze Vole

Taxonomy. Microtus fortis Buchner, 1889, left bank of the Huang Ho [=Yellow] River, Inner Mongolia, China.

Alexandromys fortis is in the subgenus Alexandromys and fortis species group. Morphological evidence and results of analysis of nuclear genes (but not of mtDNA) retrieve a sister species to A. sachalinensis . Six subspecies recognized.

Subspecies and Distribution.

A.f.fortisBuchner,1889—areasalongthegreatbendofHuangHeinChina(SpartsofInnerMongolia[=NeiMongol],Ningxia,Shaanxi,SEGansu,andNESichuan).

A.f.calamorumThomas,1902—middleandlowerpartsofYangtzeRiverBasininS&EChina.

A.f.dolichocephalusMori,1930—NEChina(EInnerMongolia,Jilin,andLiaoning).

A.f.fujianensisHongZhenfan,1981—SEChina(NFujian).

A.f.michnoiKastschenko,1910—SSiberiaandRussianFarEast(Transbaikalia,Amurarea,andNSakhalinI),N&NEMongolia,andNEChina(NInnerMongoliaandHeilongjiang).

A. f. uliginosusJ. K. Jones & D. H. Johnson, 1955 — Korean Peninsula.

Descriptive notes. Head-body 115-176 mm, tail 35-75 mm, ear 12-19 mm, hindfoot 18-26 mm; weight 36-117 g. Head and upperparts of the Reed Vole are dark grayish brown; underparts are silver-white; and tail is sharply bicolor, black above and whitish below. Sole of foot has five plantar pads. Baculum is large (4-4-5-6 mm); its base is wide, with weakly rounded proximal edge; and base is 1:7-2-5 mm wide. Distal processes are short; median is 0-9-1-6 mm long and lateral measures 0-7-1-3 mm. M?® has four inner and 3-4 outer angles. Chromosomal complement has 2n = 52 and FN = 64.

Habitat. Open habitats of boreal coniferous forest, broad-leaf forest, forest steppe, steppe, semi-desert, and desert zones. The Reed Vole occupies a wide variety of landscape types but prefers riparian habitats; it often occurs in crop fields and human settlements.

Food and Feeding. In summer, Reed Voles feed mainly on green parts of grasses, sedges, forbs, and, to a lesser extent, insects. In winter and spring, diet mainly contains roots, bulbs, seeds, and bark of trees. It stores food for winter in special chambers of burrows; winter store is c.1-4 kg/family group.

Breeding. Breeding of the Reed Vole in the wild was recorded in April-September. Litters have 1-13 young (average 5-8), and intervals between pregnancies are 17-74 days (average 29). Adult females can produce 3-4 litters/year (in some years, up to five). Pregnancies last 17-20 days. Females born in the first one-half of summer reach reproductive maturity at 45-50 days of age and produce 1-2 litters in the same season; those born at the end of summer reach reproductive maturity next spring.

Activity patterns. Reed Voles are active round-the-clock; in summer, activity is mainly nocturnal.

Movements, Home range and Social organization. Reed Voles live in family colonies. Burrows, nests, and foraging sites of each colony are connected by pathways. In summer, they construct two types of burrows: shelter burrows in foraging places and nest burrows. Shelter burrows are simple and consist of tunnels 20-40 cm in length and descend up to 10-17 cm. Nest burrows are built in dry habitat and consist of a nest chamber (12-17 cm in diameter) and 1-2 short tunnels leading to the ground’s surface. In wet habitats, nests are built aboveground. Winter burrows have complex structure and consist of a nest chamber, 1-2 storage chambers (10-19 cm deep), and a complex network of tunnels with up to 20 exits to the ground’s surface. Adult males display amicable behavior to members of its own family group (including grown-up offspring), but they are very aggressive to members of other groups; attacks with fighting and biting are common between adult males. Contacts between individuals are accompanied by acoustic communication expressed in quiet or sharp squeals and songs. Songs are produced by males at contacts with females.

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

Bibliography. Abramson & Lissovsky (2012), Allen (1940), Bannikova et al. (2010), Gromov & Erbajeva (1995), Haring et al. (2011), Kostenko (1984), Lissovsky & Obolenskaya (2011), Meyer et al. (1996), Sheremetyeva et al. (2010), Shvetsov et al. (1984), Won Changman & Smith (1999), Wu Zhengjun et al. (1996), Zhang Yongzu et al. (1997), Zorenko & Rutovskaya (2006).