Eurasian harvest mouse
Micromys minutus
Edward Lin · Neipu Township, Pingtung County
Key facts in one look
- Status in Georgia
- Vulnerable, declining
- Size
- Head and body 4.8–8 cm, 4–11 g
- Habitat
- Reed beds, tall grassland
- Family
- Muridae
- Conservation
- VU / LC
The Eurasian harvest mouse (Micromys minutus) is Europe's smallest rodent: an adult weighs 4–11 g. It grips stems with its long, prehensile tail and weaves a round nest on the stems of reeds or tall grass. In Georgia it has been found at a few places in the west: in Abkhazia near Gagra and Sokhumi, in Guria near Natanebi, and near Anikhva and Dedalauri. The 2021 national assessment lists it as Vulnerable, with a declining population. If you find a woven ball of grass fixed to stems in a reed bed, it may well be its nest.
Identification
Eurasian harvest mouse: how to identify it
A very small reddish-brown mouse with a white belly, a blunt muzzle and short ears. Its most striking feature is the long tail it uses to grip stems. It weighs about half as much as a house mouse.
Head and body 4.8–8 cm, tail 3.9–7.2 cm, weight 4–11 g. The ears are short, and the long tail is slightly prehensile: it wraps around plant stems and keeps the mouse balanced as it climbs.
The back is orange-brown, sometimes with a yellow or red tinge, and contrasts sharply with the white or cream belly. The tail is usually bicoloured and bare at the tip.
The house mouse is larger, with a uniform greyish-brown back that lacks the orange tone. The best sign of a harvest mouse is its round nest woven from grass.
Colour
Swatches are illustrative. Do not identify a species by colour alone.
Often confused with
It is a mouse of tall grass and reeds. It favours reed beds above all, also lives in cereal fields in summer, and moves into hedges and thickets after the harvest. It is mainly a lowland species, up to 1700 m. In Georgia it has been found in Abkhazia (Gagra, Novo-Troitskoe, Sokhumi), in Guria (Natanebi), and near Anikhva and Dedalauri. On the Black Sea coast the southern edge of its range reaches Kobuleti.
It eats mostly plants but is omnivorous: seeds, fruit, roots, moss and fungi. In summer it also eats insects and their larvae, and flower nectar. Mice living near fields feed on cereal grain.
It is mostly active at night, though sometimes by day. It spends much of its time on the ground but is an excellent climber, gripping stems with its tail and feet. It weaves its breeding nest, a ball 6–13 cm across, on reed or sedge stems 20–50 cm above the ground. It breeds in spring and summer: a female carries 2–12 embryos, and the young open their eyes at 8–10 days and are mature at 6–7 weeks. It spends the winter in burrows dug in the soil or in haystacks and does not hibernate.
In Georgia it is Vulnerable (VU B2a, 2021 national assessment), its numbers are falling, and its extent of occurrence in the country is about 4706 km². It is also listed as Vulnerable on the 2006 Red List of Georgia because of its small, fragmented range. Globally it is not threatened (LC, 2019). In many places its numbers are falling as natural landscapes are transformed. In Japan it suffers from wetland drainage, pesticides and the loss of grassland.
Related guides
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Yes, in Europe. An adult harvest mouse weighs 4–11 g, about half a house mouse. Its head and body are 4.8–8 cm long, with a tail of almost the same length. A newborn weighs less than a gram.
It has been found at a few places in western Georgia: in Abkhazia near Gagra, Novo-Troitskoe and Sokhumi, in Guria near Natanebi, and near Anikhva and Dedalauri. It favours reed beds and tall grass. Its range in the country is about 4706 km².
Like a ball woven from grass, 6–13 cm across. It is fixed to reed or sedge stems 20–50 cm above the ground. The outer layer is made of leaves of the same plant the nest hangs on. If you find one, do not touch it: it may hold young.
No, it does not attack. It is, however, a natural carrier of the agents of several diseases, including tularaemia and leptospirosis. So do not touch the mouse with bare hands.
References
What this profile is based on
Species profiles are compiled from peer-reviewed literature and established biodiversity databases, and are reviewed as new taxonomic and conservation data become available.
Prepared by the Reptiles.ge editorial team from the sources listed here.
