Latin: Arvicola Terrestris
The water vole is a type of stud mouse. Stud mice can be recognized on their blunt snouts, short tail, short limbs, as well as small ears. This is in great difference from rats, which have an elongated snout, and whose tails are almost the same length as the body itself. The water vole is occasionally called water rats or ground rats, but as explained, they are not related to rats at all. Instead, they are closer related to the field mouse, which is also a type of stump mouse.
Appearance
A water vole can be recognized by its round compact shape. It has fairly small ears and a short, thin tail. The head is rounded, and they do not have much snout. Water voles typically have a darker brownish color all over the body, although the head can appear as lighter in color. The tail is also dark brown. Without the tail, an average Water vole is 12-22 cm long. The tail is between 5 – 11 cm long. Water vole can weigh up to 200 grams. There is no visible difference on the male and female water vole.
Biology and behavior
In the past, they were mainly found in wet and damp terrain. They are extremely skilled swimmers, but in recent time, they have been found in drier terrain. Water vole now and then live near streams and ponds, which has given them a bad reputation for stealing ducklings. However, it is typically the brown rats that does this and not the water vole. The water voles have so far shown to be herbivores, and they make depots of food such as carrots, potatoes, onions, and quick grass.
The water voles typically breed from April to November. During this long period of time, they typically get 4 to 5 litters. In total, this will be about 20 pups. Already as 2 months old, the pups are able to mate, which can lead to a sudden and drastic growth of water voles. However, they typically have a short life span, just 15-20 months.
Damage
The water vole is especially harmful as it digs up gardens, and parks. It can also wreak an orchards and ornamental plants, as it gnaws at the roots of shrubs and trees. Much like the mole, the water vole makes systems and mole holes. In fact, it can be difficult to determine whether mole hole in one’s lawn are from moles or water vole, as the two leave similar tracks. The water vole can move into abandoned passages from moles and vice versa, which does not make it easier.
If there are many open holes in between the mole holes, and it is during the summertime, it is typically the water vole. Moles usually close their holes when they dig down again, but water vole leaves them open every now and then. The water vole’s holes can vary in size, but they are typically between 5 and 8 cm in diameter.
In the ground, the water vole can also do great damage to underground cables, by gnawing into them.
Prevention and control
In 2004, a law was passed on the controlling of the water vole. The law “Lov om drift af landbrugsjorder” ” (Act no. 434 of 9 June 2004) states that the individual municipality can finance control against water voles for a fee from the owners of the affected properties. However, this is not binding, so it is possible for individual citizens to control water voles at their own expense without involving the municipality. In addition, there is no obligation to report invasions by water voles. This law applies to both the control of water vole and moles.
You cannot prevent water voles, but you can control them on private properties. However, it can be difficult because of the high fertility rate, with means that a few individuals will most likely survive the pest control. Water voles that live close by can begin to invade a cleansed area after a short time. Therefore, they are best fought when all neighbors or a landowner’s association stand together. Poison must not be used to control water voles. Instead, a person who has completed a course can use phosphorus hydrogen-developing pellets. These pellets can also be used to control moles. To use this solution, you should contact the municipality’s technical administration or a private company for pest control. Alternatively, traps can be used, which in most cases will work fine. It is allowed to used traps which kills the animals, such as mole scissors and rat traps.