Water vole
The water vole (Arvicola amphibius, formerly Arvicola terrestris) is a large, semi-aquatic vole that burrows into soft riverbanks. In Britain it has had one of the steepest declines of any animal: its numbers fell by 94% between 1990 and 1999.[1]
Description
The water vole is slightly smaller than the brown rat. It has a furry tail about half the length of its body, a rounded muzzle and ears hidden in its fur. Its colour ranges from light brown to almost black in Scotland. The head and body measure 14 to 22 cm, the tail 9 to 14 cm, and adults weigh 150 to 300 g. It makes a "plop" as it enters the water.[1] Its signs include burrows 4 to 8 cm across at or just above the water line, piles of grass clippings, and latrines of droppings.[2]
Habitat and behaviour
Water voles live along slow rivers and in freshwater marshes. Some Scottish populations live away from water and burrow like moles.[2] They eat only plants, mainly grasses, reeds and sedges; 227 plant species have been recorded in their diet. Each vole holds a territory of 25 to 200 m along a riverbank. They breed from March to September, with up to five litters a year of about six young each.[3]
History in Britain
Water voles are common in archaeological deposits. They are the main small mammal, together with field voles, in many sites from the Neolithic to the Iron Age. For example, they made up 68% of the small mammals at the Iron Age site of Winnal Down in Hampshire. Their abundance at sites far from water was first noticed at Snail Down in 1959. Since the Mesolithic, British water voles have become larger, with more upright front teeth.[4] They are absent from Ireland, the Isle of Man and Jersey.[5]
Decline
A national survey in 1986–88 found water voles at only 32% of the sites that had been occupied between 1900 and 1940. Declines continued after the survey of 1989–90; in the Thames basin, the share of sites with voles fell from 74% to 24%.[6] Yalden and Barrett link the decline since the 1970s to the spread of the American mink, which can wipe out vole colonies in the narrow strips of bankside habitat that remain.[7] Couzens and colleagues give the population as about 875,000 and still falling. They name habitat loss, intensive farming, pollution and mink as causes.[3]
Protection
The water vole is protected under Schedule 5 of the Wildlife and Countryside Act.[7] Couzens and colleagues record it on the biodiversity lists for England, Wales and Scotland.[1] Yalden and Barrett suggest that leaving a metre or two of rank vegetation along riverbanks would help. They also discuss reintroducing voles where new riverside habitat is created.[6]
See also
References
- ↑ 1.0 1.1 1.2 Couzens, Dominic; Swash, Andy; Still, Robert; Dunn, Jon (2021). Britain's Mammals: A Field Guide to the Mammals of Great Britain and Ireland (Updated ed.). Princeton University Press. p. 76. ISBN 9780691224862.
- ↑ 2.0 2.1 Couzens, Dominic; Swash, Andy; Still, Robert; Dunn, Jon (2021). Britain's Mammals: A Field Guide to the Mammals of Great Britain and Ireland (Updated ed.). Princeton University Press. p. 77. ISBN 9780691224862.
- ↑ 3.0 3.1 Couzens, Dominic; Swash, Andy; Still, Robert; Dunn, Jon (2021). Britain's Mammals: A Field Guide to the Mammals of Great Britain and Ireland (Updated ed.). Princeton University Press. p. 78. ISBN 9780691224862.
- ↑ Yalden, Derek; Barrett, Priscilla (2010). The History of British Mammals. T & AD Poyser. ch. 4. ISBN 9781408128718.
- ↑ Yalden, Derek; Barrett, Priscilla (2010). The History of British Mammals. T & AD Poyser. ch. 8. ISBN 9781408128718.
- ↑ 6.0 6.1 Yalden, Derek; Barrett, Priscilla (2010). The History of British Mammals. T & AD Poyser. ch. 9. ISBN 9781408128718.
- ↑ 7.0 7.1 Yalden, Derek; Barrett, Priscilla (2010). The History of British Mammals. T & AD Poyser. ch. 7. ISBN 9781408128718.