Living in Kent you could be mistaken for thinking that water vole are plentiful. Their burrows and piles of chopped vegetation seem to line every ditch and river bank in the county, but while water voles thrive in Kent the story is not the same everywhere. In Cornwall for instance numbers have struggled and loss of ditch systems, coupled with pressure from mink, have seen water vole numbers plummet nationally by as much as 90%.
They key to a healthy population of water vole is a good network of suitable habitat. In areas with many ditches such as Stodmarsh National Nature Reserve water voles can even survive alongside mink as they can recolonize an area and build their numbers back up once a mink has moved on or been captured.
This is why every piece of water vole habitat is protected under the Wildlife and Countryside Act, making it an offence to kill an animal or destroy it’s burrow. The law is not there to stop lawful management of water ways but it does mean that the needs of water voles need to be considered and mitigation measures put in place.
Carol Donaldson Associates has recently worked with two landowners, the RSPB at Lydden Valley and St Augustines Golf Course to advise on water vole mitigation measures. The RSPB have a need to widen ditches in order to restore the valley to wet grazing marsh and create a system of reedbeds and lagoons of benefit to breeding waders and St Augustines Golf Course wish to create a new pond attached to a chalk stream which flows through the site.
“Both these projects,” said Carol Donaldson, “will ultimately benefit wildlife but we need to ensure water vole populations are properly managed to prevent animals being harmed and to stay within the law.
In both situation it should be possible to move the animals temporarily away from their burrows systems without the need to trap them which can be stressful for the animals and costly for the landowner. We use a destructive bank technique where vegetation is removed from the site to be developed and the site is checked daily by an ecologist to ensure no animals are present. When all field signs have vanished burrows will be excavated by hand and then the bank can be peeled off in layers.”
In this way due care is given to the needs of water vole and once the banks have re-established animals can re-colonise.
This type of work is only suitable for moving a few animals from a short stretch of bank and larger schemes would still need to involve more complex programmes of relocating animals.
“Many people see the law surrounding water voles as a hindrance to their plans.” Said Carol Donaldson, “but it can often be an opportunity to re think a scheme and create something of greater benefit to both people and wildlife.”