The Discovery of a Water Vole at Amwell

8th July 2014

Water Voles used to be present at Amwell but then the American Mink arrived and wiped them out. I always say that if you don't see Mink on a reserve you almost certainly have them, and if you do see them you really do have a problem. This is because Mink are mainly nocturnal, but when numbers build up they will hunt by day. It was about 10 years ago at Amwell that Mink could be seen running across the Lee Navigation towpath and along the bank in front of the viewpoint.

When Herts and Middx Wildlife Trust bought Amwell Quarry in December 2006, five mink rafts were installed around the site and in the first year about 20 Mink were caught. In subsequent years just a few animals were caught and it is now over a year since the last Mink was trapped. Therefore, Amwell can be regarded as reasonably Mink-free at the present time. As a result the first signs of the return of Water Voles to the area have been seen over the last few months, all along the Magna Fishey on the old River Lea consisting of just one or two sightings and some droppings. Hopefully they will spread into the surrounding area.

Today I had gone to Amwell with the sole intention of looking for Emerald Damselflies on the Dragonfly Trail at Hollycross Lake. Although it was quite warm with the sun out for a while there was no sign of any Emeralds. However, although they should be on the wing by now, I seem to remember that last year's records were a little later in the season. I then moved back to the pond between the viewing platform and Hollycross Lake itself and couldn't believe my eyes, for there right in front of me was a Water Vole gnawing away at some vegetation.

Water Voles have never been recorded on the Dragonfly Trail since its formal opening on the 4th July 2008 and, as stated above, have been absent on site for more than 10 years. In my opinion their return to the site is a direct result of the long-term programme of Mink raft monitoring that has been carried out and credit must go to Andy Johnson for his tireless work in monitoring the rafts each week.

The photo was taken about 12 feet in front of the right-hand end of the main viewing platform looking at Hollycross Lake. At this point there is a stand of Common Bulrush Scirpus lacustris, a fairly scarce plant despite its name and as far as I can remember, apart from the old River Lea which is not part of the reserve, this is the only place on the reserve where it is found. It may not be present for much longer, however, as it is systematically being devoured by the vole as can be witnessed by the dozen or so stems that have been chewed off about six inches above the water, two of which can be seen in the photo.. Hollycross Lake and the dragonfly ponds provide ideal habitat for Water Voles so let us hope that they build up a colony, as not only will it be great to have them back on site, but the Dragonfly Trail boardwalk will provide an ideal vantage point for seeing them.

Well, I didn't see my Emerald Damselflies, but what a consolation prize.