# Water Vole — Facts, Threats & Conservation

*Arvicola amphibius*

> A water vole (Arvicola amphibius) is a large, semi-aquatic rodent found along rivers, ditches and reed beds across Europe and western Asia. With chestnut fur, a blunt muzzle and a furry tail, it is a true vole — not a rat — and the inspiration for "Ratty" in The Wind in the Willows.

**IUCN status:** Least Concern globally; rapidly declining in the UK  ·  **WARN range:** Europe, Russia, West Asia, Kazakhstan, United Kingdom

## Quick facts
| Fact | Value |
| --- | --- |
| Common name | Water vole (also "water rat") |
| Scientific name | Arvicola amphibius |
| Type | Semi-aquatic rodent (vole) |
| Head-and-body length | About 14-22 cm, plus a furry tail |
| Weight | Roughly 150-300 g in adults |
| Diet | Mostly vegetarian — grasses, sedges, rushes and roots |
| Habitat | Riverbanks, ditches, reed beds and wetlands |
| Range | Europe, Russia, West Asia and Kazakhstan |
| Lifespan | Usually a few months in the wild; up to ~2.5 years in captivity |
| Famous for | Being "Ratty" in The Wind in the Willows |

## Scientific classification
- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Mammalia
- **Order:** Rodentia
- **Family:** Cricetidae
- **Genus:** Arvicola
- **Species:** Arvicola amphibius

## Conservation status
- **Status:** Globally assessed as Least Concern by the IUCN Red List, reflecting a very wide range across Europe and into Asia. In the United Kingdom, however, the water vole is one of the fastest-declining mammals and is strictly protected under wildlife law, having disappeared from much of its former range due to habitat loss and predation by invasive American mink.
- **Population:** No reliable global total; the species is widespread but local populations, especially in Britain, are fragmented and have fallen sharply.
- **Trend:** Stable globally, but steeply declining in the UK
- **Assessed:** 2021
- **CITES:** Not listed on the CITES Appendices
- Globally Least Concern but a major conservation concern in Britain, where it and its burrows are legally protected and recovery focuses on restoring connected wetland habitat and controlling invasive mink.

## Key facts: Water Vole
- The water vole is a true vole, not a rat — note the blunt rounded muzzle, small ears almost hidden in fur, and short furry tail.
- It is the largest vole in Britain and the real-life inspiration for "Ratty" in Kenneth Grahame's The Wind in the Willows.
- Globally the species is assessed as Least Concern by the IUCN, with a wide range across Europe, Russia and western Asia.
- In the United Kingdom it is one of the fastest-declining mammals, driven by habitat loss and predation by the invasive American mink.
- Water voles are mainly vegetarian, grazing waterside grasses, sedges and rushes, and give themselves away with a distinctive "plop" as they dive.
- They are strictly protected in Britain, where their burrows and habitat are safeguarded by law.

## What does a water vole look like and how is it different from a rat?
A water vole is a plump, round-bodied rodent measuring roughly 14-22 cm in head-and-body length, with a tail about half that again. Adults typically weigh between about 150 and 300 grams, making this the largest vole in Britain. Its fur is usually rich chestnut to dark brown, occasionally near-black in parts of Scotland. The features that distinguish it from the superficially similar brown rat are worth learning: the water vole has a blunt, rounded muzzle rather than a pointed snout, small ears that barely show above the fur, and a short, hair-covered tail instead of the rat's long, scaly, near-naked one. Its eyes are small and its overall silhouette is rounded and chubby. When alarmed it dives into the water with a characteristic "plop", a sound that often reveals its presence before it is seen. Because of this resemblance, and the famous character "Ratty", many people wrongly assume water voles are rats — but they are gentle, plant-eating voles.

## Where do water voles live and what do they eat?
Water voles are semi-aquatic and tied to fresh water. Across their range they occupy the banks of slow-flowing rivers and streams, ditches, canals, marshes, reed beds and ponds, and in some upland areas they live in damp peatland and grassland away from open water. The species ranges widely across most of Europe, into Russia, parts of West Asia and Kazakhstan, and can be found from sea level up to around 1,000 metres in mountainous regions. They dig extensive burrow systems into soft, vegetated banks, with entrances at and below the waterline, and create networks of runs and feeding lawns through the surrounding vegetation. Their diet is overwhelmingly vegetarian: grasses, sedges, rushes, reeds and waterside herbs make up the bulk of it, supplemented by roots, bulbs, fruits, twigs and bark, especially in winter. Distinctively grazed grass stems cut at a neat 45-degree angle, along with latrines of small, rounded droppings, are classic field signs that water voles are present.

## Why are water voles disappearing in Britain?
Although the water vole is globally Least Concern, in the United Kingdom it has suffered one of the most dramatic declines of any British mammal, vanishing from large parts of its former range over recent decades. Two pressures drive this. The first is habitat loss and fragmentation: the canalisation and dredging of watercourses, drainage of wetlands, intensive bankside farming and urban development have stripped away the lush, vegetated banks water voles depend on, leaving isolated populations cut off from one another. The second, and especially severe, factor is predation by the American mink — a non-native carnivore that escaped and was released from fur farms. Female mink are small enough to enter water vole burrows and can wipe out entire colonies, a pressure the voles have no evolved defence against. Because of these threats, water voles and their burrows are strictly protected under wildlife law in Britain, and recovery depends on restoring connected, well-vegetated waterways and controlling invasive mink.

## How do water voles breed and how long do they live?
Water voles have a fast, prolific breeding strategy that helps offset high natural mortality. The breeding season runs from spring into late autumn, roughly March to October. After a gestation of about 21 days, a female gives birth to a litter of typically three to eight young in a nest within her burrow or, sometimes, woven among reeds. A female may produce several litters in a single season, and young from early litters can themselves breed before the year is out. The young are weaned and independent within a few weeks. Life is short and hazardous: most wild water voles live only a few months, and few survive more than two winters, as they are heavily preyed upon by herons, owls, stoats, pike and, where present, mink. This boom-and-bust pattern means healthy populations can bounce back quickly when habitat is good and predation is low — which is exactly why restoring riverbanks and tackling invasive predators can turn local fortunes around.

## Water vole vs brown rat: how to tell them apart
| Feature | Water vole | Brown rat |
| --- | --- | --- |
| Muzzle | Blunt and rounded | Pointed and long |
| Ears | Small, almost hidden in fur | Prominent and visible |
| Tail | Short and furry (about half body length) | Long, scaly and near-hairless |
| Body shape | Plump and rounded | Sleeker, more elongated |
| Diet | Almost entirely plants | Omnivorous, opportunistic |
| In the water | Dives with a clear "plop" | Swims but less specialised |

## What WARN does
WARN does not run field projects specifically for the water vole — the species lives mostly outside the five countries where WARN's partners work, and this guide is part of WARN's free educational mission to help people understand and value wildlife. The threats that hit water voles hardest, however — habitat loss, drained and degraded wetlands, and pressure from invasive species — are exactly the kinds of pressures that bear down on the animals WARN's partners do protect.

If learning about the water vole sparked a little wonder, a small gift helps keep WARN's free wildlife guides growing and supports the animals our partners protect.

## Frequently asked questions: Water Vole
### Is a water vole a rat?
No. Despite its size and brown fur, the water vole is a true vole, not a rat. You can tell them apart by the vole's blunt, rounded muzzle, small ears nearly hidden in its fur, and short, furry tail — compared with a brown rat's pointed snout, prominent ears and long, scaly, almost hairless tail. The confusion is reinforced by "Ratty", who is actually a water vole.

### Why is the character "Ratty" in The Wind in the Willows a water vole?
In Kenneth Grahame's 1908 classic The Wind in the Willows, the riverbank-loving character "Ratty" is named as a Water Rat, but the animal described — messing about in boats along a gentle English river — is a water vole. The old country name "water rat" caused the mix-up. Ratty has become so beloved that he is now the species' best-known cultural ambassador.

### What do water voles eat?
Water voles are almost entirely vegetarian. They graze on grasses, sedges, rushes, reeds and other waterside plants, and supplement this with roots, bulbs, fruits, twigs and bark, particularly in winter. They have been recorded occasionally eating aquatic invertebrates, but plant material dominates their diet. Neatly grazed stems cut at a 45-degree angle are a classic sign that water voles are feeding nearby.

### Are water voles endangered?
Globally, the water vole (Arvicola amphibius) is assessed by the IUCN as Least Concern, thanks to its very wide range across Europe and into Asia. The picture is very different in the United Kingdom, where it has become one of the fastest-declining mammals due to habitat loss and predation by invasive American mink, and is strictly protected by law. So the answer depends heavily on where you are.

### What is the main threat to water voles in the UK?
The two biggest threats are habitat loss and the invasive American mink. Drainage of wetlands, canalisation and dredging of rivers, and intensive bankside land use have destroyed the vegetated banks water voles need. On top of this, female American mink are small enough to enter water vole burrows and can wipe out whole colonies, against which the voles have no evolved defence — a combination that has caused steep, widespread declines.

### How long do water voles live?
Most water voles live only a few months in the wild, and relatively few survive more than two winters. They face heavy predation from herons, owls, stoats, pike and mink, as well as harsh winters. To balance this, they breed rapidly — a female can raise several litters of up to eight young between spring and autumn — so populations can recover quickly when habitat is healthy and predators are kept in check.

## Sources
- [European water vole — Wikipedia](https://en.wikipedia.org/wiki/European_water_vole)
- [IUCN Red List — Arvicola amphibius](https://www.iucnredlist.org/species/2149/197271067)
- [Water vole — Encyclopaedia Britannica](https://www.britannica.com/animal/water-vole)
- [The Wind in the Willows — Wikipedia](https://en.wikipedia.org/wiki/The_Wind_in_the_Willows)
- [American mink — Wikipedia](https://en.wikipedia.org/wiki/American_mink)

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Full guide: https://worldanimalrescuenetwork.org/wildlife-guides/water-vole