Eurasian water vole
Arvicola amphibius
Jakob Fahr · NSG Riddagshausen
Key facts in one look
- Size
- Body 12–23 cm, weight 80–320 g
- Diet
- Herbivore: grasses, tubers, rhizomes
- Status in Georgia
- Resident; declining in the west
- Habitat
- Marsh, lake and river banks, pasture
- Family
- Cricetidae
- Conservation
- LC / LC
The Eurasian water vole (Arvicola amphibius) is one of the largest voles: it weighs 80–320 g and swims well. It lives along slow or still water, in marshes, around lakes and ponds, by ditches and along rivers. In Georgia the eastern population is in normal condition, but in the west competition with the brown rat has reduced it sharply. It feeds mainly on green plants, tubers and rhizomes. It is the main carrier of tularaemia, so do not touch one with bare hands, alive or dead.
Identification
Eurasian water vole: how to identify it
A large, robust vole with a heavy head, short ears that barely show above the fur, and small eyes. The back is mostly brown, the belly grey, and the tail and paws blackish brown. It looks like a rat, but its snout is rounder and its ears and tail are covered in fur.
Head and body 120–230 mm, tail 58–139 mm, weight 80–320 g. Aquatic forms are always larger. Males are larger than females. In aquatic forms the tail is 48–82% of the body length; in burrowing forms it is 40–59%.
Most animals have a brown back and a grey belly, with no sharp line along the flanks. In many populations the belly has a buff wash. Some populations are entirely black, and in Armenia 91% of animals are greyish brown. The tail and paws are blackish brown.
It resembles the brown rat and is often called the "water rat", but it is not a true rat. Its snout is rounder, its ears short and furry, and its tail and paws are covered in fur. A rat's tail is not furred like this. If you see such an animal at the water's edge, look at its tail.
Colour
Swatches are illustrative. Do not identify a species by colour alone.
The Eurasian water vole lives from sea level to 3210 m, and in the Caucasus up to about 3200 m. The aquatic form usually stays within 2 m of the water's edge: in marshes, around ponds and lakes, by ditches, streams and rivers. The water must be there all year round, still or flowing slower than 0.5 m per second. It needs steep loamy or sandy banks to dig its burrow, and dense vegetation for food and cover from birds of prey. The burrowing form lives mainly in the mountains and occupies pastures, forest clearings, fields and orchards. In Georgia the water vole lives in both the east and the west. The population of eastern Georgia is in normal condition. The population of western Georgia has declined sharply because the brown rat, which lives alongside people, competes with it.
The Eurasian water vole map combines public iNaturalist observations. Regions are taken from the records-by-region table, and the status column separates regions with enough records from regions with too few records. Record counts reflect observation effort rather than population density. Records are still too few to mark any region.
Data: Reptiles.ge + iNaturalist · Methodology
- Field observation
- Region with records
The Eurasian water vole feeds mainly on green plants, tubers and rhizomes. Every day it eats about 80% of its own body weight. It often takes common reed, cattail, sedges, nettles and other waterside plants. It stores food underground for winter: one burrow may hold 4–5 kg. In gardens it eats carrots and potatoes, and in orchards it damages bark and roots. It rarely eats insects, molluscs, crabs or fish.
The Eurasian water vole is active by day and by night. It swims well: air trapped in its dense fur adds insulation in the water. On land it uses runways 4–9 cm wide hidden in dense vegetation and avoids crossing open ground. Its burrow in the bank holds a nest and a food store. Females defend their territories; males do not. In central Europe the breeding season runs from March to September. Pregnancy lasts 20–30 days. A female has 1–5 litters a season, about three on average, with 1–11 young each, usually 4–6. The young are born naked with closed eyes and weigh 3.5–5.7 g. It can live up to three years, but few survive a second winter.
Globally the Eurasian water vole is not threatened (LC, 2021): it has a vast range and a stable overall population. Georgia's 2021 national assessment also lists it as Least Concern (LC). In the country its two populations are in different condition: the eastern one is normal, while the western one has declined sharply because of competition with the brown rat. It has crashed in some European countries: in Great Britain it declined by about 94% in the 1990s.
Related guides
Continue with related pages
Its main risk is disease. It is the main carrier of tularaemia and also spreads leptospirosis. People are most often infected while skinning the animals. Do not touch a water vole with bare hands, alive or dead.
No. It is often called the "water rat", but it is a vole of the family Cricetidae. Its snout is rounder, its ears short, and its tail and paws furry. In western Georgia the brown rat is its competitor and the reason for its decline.
In both the east and the west, along waterside places. The population of eastern Georgia is in normal condition. The western one has declined sharply because of competition with the brown rat.
Mainly waterside plants, tubers and rhizomes, about 80% of its body weight a day. For winter it stores up to 4–5 kg of food underground. In gardens it eats carrots and potatoes.
Sometimes, yes. During population outbreaks it damages fields, pastures, vegetable plots and orchards. In orchards it gnaws bark and roots. At the same time, in some European countries it is a rare and protected species.
Globally it is not threatened (LC, 2021), and Georgia's 2021 assessment also lists it as LC. Even so, its population in western Georgia has declined sharply. In Great Britain it fell by about 94% in the 1990s.
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.
