627.

Eurasian Harvest Mouse

Micromys minutus

French: Rat des moissons / German: Eurasische Zwergmaus / Spanish: Raton espiguero

Other common names: Harvest Mouse

Taxonomy. Mus minutus Pallas, 1771,

Simbirsk (= Ulyanovsk), Middle Volga River, Russia.

In 2016, M. Pages and colleagues demonstrated that Micromys merits a monospecific tribe, Micromyini, which is the sister taxon of Rattini (including Dacnomys division). Phylogeographic analysis of the species by S. P. Yasuda and colleagues in 2005 suggested very low genetic distance among the different populations, with the exception of a single individual from China, which might constitute a valid species. Abramov and colleagues in 2009 determined that Vietnamese populations also clustered with this Chinese individual, being morphologically distinct from M. minutus as well, and came to the conclusion that they represented a separate species, M. erythrotis, although this is based upon few samples and further research is needed to validate these findings. Four geographic clades are distinguished (Europe; Korea-Japan; Russia; Taiwan) but their low degree of divergence suggest a recent and rapid recolonization of Europe from refugia in Central to East Asia during the last climatic optimum period. Monotypic.

Distribution. From N Spain and Britain E through Europe, Russia, and Kazakhstan to N Mongolia, China, Korea, Japan, NE India, Myanmar, Laos, and Vietnam.

Descriptive notes. Head—body 48-80 mm, tail 39-72 mm, ear 8-10 mm, hindfoot 12— 16 mm; weight 4-11 g. The Eurasian Harvest Mouse is one of the smallest Murinae. [t is also characterized by short ears and a long,slightly prehensile tail. Dorsal pelage is orange brown and contrasts with the white underparts. Females bear four pairs of mammae. Karyotype is 2n = 68.

Habitat. Lives in lowlands, occurring up to elevations of 1700 m. It is primarily specialized to life among reeds, where the nestis situated 20-50 cm above ground; to a lesser degree, it isalso adapted to living in cereals fields, where it occurs during summer. Immediately after harvest, it takes refuge in hedges surrounding fields, and builds another nest among brambles or in hawthorn thickets. In Japan and China, nests have been found placed on the ground of cereal fields or meadows.

Food and Feeding. The Eurasian Harvest Mouse is a plant-dominated omnivore that eats seeds, fruits, roots, moss, other plant matter, fungi, and small amounts of invertebrates.

Breeding. Reproduction is seasonal, with highest proportion of births during spring and summer. Females can bear 2-12 embryos, and mean litter size varies from 4-8 to 5-3, depending on the region. Young open their eyes after 8-10 days, and are weaned around day 18. Sexual maturity is achieved 6-7 weeks after birth.

Activity patterns. The Eurasian Harvest Mouse is generally nocturnal, but sometimes active during the day. Itis terrestrial, but also a good climber; it spends most ofits time on the ground and takes refuge in the nest. In winter, the species uses burrows dug in the soil.

Movements, Home range and Social organization. Eurasian Harvest Mice may be found in variable densities in function of meteorological conditions. Density 6-25 ind/ha; may occasionally pullulate. Home ranges are between 350 m? (females) and 400 m? (males).

Status and Conservation. Classified as Least Concern on The IUCN Red List. In some parts of its range, the species is considered a pest.

Bibliography. Abramov et al. (2009), Aulagnier et al. (2009), Corbet (1978), Haberl & Krystufek (2003), Pages et al. (2016), Quére & Le Louarn (2011), Smith & Yan Xie (2008), Yasuda et al. (2005).