Current status of the water vole
The water vole is listed as a UK and Local Biodiversity Action Plan Priority Species. Protection for water vole was granted under Schedule 5 of the Wildlife and Countryside Act in 1998. It is now illegal to knowingly destroy water voles' place of shelter. This protection does not prevent maintenance work on riverbanks but does ensure reasonable care is taken to aviod damage of known sites.
There has been a serious decline of numbers in Britain with water voles lost from 89% of their occupied sites this century.UK surveys from 1989 and 1998 recorded a dramatic rate of decline. In Scotland, 239/730 sites surveyed in 1989 held water voles, with only 70/730 sites occupied in the repeat 1998 survey - catastrophic results.
Extensive surveys in the catchment of the Rivers Dee, Don and Deveron have been carried out by Aberdeen University and SNH. A first survey of the upper river Dee found voles were widely distributed in 3 headwater sub-catchments where 67 small sub-populations were found in backwaters and slow-flowing sections. Water voles have dramatically declined in sub-catchments of the river Dee which have been invaded by mink during the last 5 years.
An SNH survey identified 6 colonies in the catchment area of the River Deveron, one colony on a tributary of the Blackwater near Cabrach is also known. Water voles have disappeared from the headwaters of the River Don.
Current factors affecting water voles
American Mink.
Evidence suggests that the overriding factor causing the decline of the water vole in north east Scotland is predation by American mink. The mink were brought to Britain to be farmed for fur. A drop in demand for fur led to widespread releases abd the mink have become established in the wild. Though only small, about a third of the size of an otter, mink are a fearsome predator and take fish as well as waterside mammels and birds.
Habitat degradation
Lowland water voles in north east Scotland live along short sections of feeder streams and ditches in the midst of intensive agricultural land. In these areas, dredging or cattle tramping can destroy areas of suitable habitat.
Dredging
Dredging of field drains results in habitat destruction. Recovery of the habitat can take considerable time - up to 2 years.
Water voles are extremely fecund and very efficient at dispersing and will be able to naturally recover when conditions are right.
Action plan
- Maintain the current distribution and abundance of the water vole.
- Identify key areas still holding significant water vole populations.
- Raise awareness of water vole conservation issues.
- Ensure appropriate habitat management in occupied and non-occupied sections of 'key areas' to protect water margin habitat for voles.
- Co-ordinate and support mink control activities.
- Reduce the impact of dredging and drainage schemes in small tributaries, promote water vole friendly drainage practices.
- Inform farmers and land owners of the presence of water voles.
How to recognise Giant Hogweed
Closely related to common Cow Parsley - the two are similar in shape and colour. Giant Hogweed can grow in excess of 4 metres high and is naturalised by rivers.
The stem is green with dark red spots, is ribbed and had sparse, spiky hairs. Stems may be as thick as 10cm in mature plants.
The leaves can be up to a metre across and over two metres long.
The flowers are white, up to half a metre across and comprise clusters of smaller flowers forming an umbrella-shaped structure.
How it should be controlled
It is important that the plant is kept under control, even irradicated where possible. Using mechanical methods, the plant can be cut, mown or pulled. Physical control should never be undertaken unless protective clothing is worn.
Cutting before flowering will only achieve temporary control - the plant will regrom the following season.
Cutting after flowering has no benefit once the seeds have been formed. Small infestations can be controlled by digging out the whole plant. The relevant competent authority (English Nature, Wildlife Trust, Local Authority) must be satisfied that the management plan is appropriate.
The plant can also be controlled chemically. This method should only be considered after other practical methods have been ruled out. Properly used, the herbicide glyphosate (Roundup, Spasor, Sonic...) is most effective. Prior agreement with the Environmental Agency must be obtained before a herbicide can be applied in or near water.
The plants may be sprayed with Glyphosate at a rate of 5 litres per hectare when growing actively but less than a metre tall, usually between April and May.
Control measures will only affect mature plant and so due to the longevity of the seeds, regular annual checks should be made for germinating plants.