2 February: Water Voles

Today is World Wetlands Day. Wetlands are an important habitat for wildlife, including water voles. Here are ten things you might not know about them:

1. They belong to the genus Arvicola, and are sometimes known as the water rat or water dog.

2. They must eat 80% of their body weight each day to survive.

3. Water voles in Britain have been recorded eating 227 different species of plant. These include reeds, grasses, rushes, sedges, roots, rhizomes, bulbs and tree bark. They have been spotted as high as 2.5 metres up a tree. They will also eat insects and other invertebrates occasionally.

4. They are found in mainland Britain but not in Ireland, the Channel Islands, Anglesey, the Isle of Wight or the Sound of Jura Islands.

5. They typically live in colonies spread out along a watercourse. They are territorial. Females fiercely defend their territory, marking them by latrines. Their poo has no scent, so they’ll rub their feet on the scent glands on their chests and then walk over their poo.

6. Females produce between two and five litters of two to eight young a year. The babies leave home after 28 days. Juvenile water voles need to weigh at least 170g to survive winter.

7. There are colonies of water vole which don’t live anywhere near water at all. They live in burrows like Moles and forage above ground. One such colony lives in an area of rough urban grassland in Glasgow.

8. Water voles in Scotland are descended from migrants from the Iberian peninsula. Those in England and Wales are descendants of from water voles from south east Europe which recolonised Britain following the last Ice Age.

9. Water vole populations have fallen by 90% since 1970. Minks escaping from mink farms would commonly eat them. An even bigger threat, however, is the drainage of natural wetlands and the agricultural and urban development of river banks.

10. 'Ratty' in Kenneth Grahame's The Wind in the Willows is a water vole.