Water vole activity or not?

[Howard Field]

I have today seen activity of an animal beneath slabs all round the edge of a moderately large garden pond --- 30 x 20 metres --- in the flood plain of the River Severn but 200 metres away from it. They look like burrows about 4 cm in diameter with exits/entrances at various intervals onto the pond just above the water line. "Water voles" I'm thinking ... until I find quite a few [30] empty water snail shells in one cavity beneath one slab and I don't think that water voles eat snails. If not water vole activity what else might it be?

[Billy Wobble Dagger]

I don't thinks it's unheard of for water voles to eat snails, but its rare, I would think more likely that it is rats specially with that number of shells.

BWD

[Howard Field]

You could be right --- thanks for replying --- but would rats swim into and under the water to harvest water snails?
I'm trying to see if it could be a water vole by throwing some half apples into the water which they simply cannot resist. If the apples are still there tomorrow, then we're back to another possibility.

[aeshna5]

Originally Posted by Howard Field

You could be right --- thanks for replying --- but would rats swim into and under the water to harvest water snails?
I'm trying to see if it could be a water vole by throwing some half apples into the water which they simply cannot resist. If the apples are still there tomorrow, then we're back to another possibility.

Rats like apples too!

[vole-woman]

I think water voles do sometimes eat snails, and crayfish too. There's even a record of a pregnant female w-v eating a fish.

I posted about snails a few years ago: About a Brook: Well blow me, water voles eat snails. In this case, there was chopped grass and water vole droppings right next to the snail shells. I don't know 100% it was w-v activity, but I'm strongly inclined to think it was.

As for field signs, the only definitive one is to find droppings. Rat footprints and w-v ones look the same, and feeding stations made of chopped vegetation can be field vole (if they're on a small scale). There are pics of droppings and the two types of feeding station on my blog, if it's any help.

I hope it turns out to be water voles, Howard!

[vole-woman]

Re the burrows, 4cm sounds about the right size - they say you can fit a Pringles tube down one - where rats' are a bit bigger. But the obvious difference is that rats make a spoil heap outside theirs because they dig into the bank. Water voles come up from below, kicking soil into the water, so the land entrances to their burrows are neat. Often there'll be nibbled grass round the entrance, too.

[Howard Field]

Thanks, Kate, for your comments, observations and really helpful info on your excellent blog site ! Superb! Nice photograph(s) !!! I shall have another look tomorrow although it's unfortunate that the bank was being cleared, i.e. the slabs were being taken up for reseating purposes when the discovery of runs / exits into the water was made; this will have disturbed any mammal that was using them which is a great pity. I'll just have to wait for the vegetation to regrow although this time of year is obviously not the best for that. I hope it's water vole activity, too.

[Apackofangrybats]

I observed the same thing - snail shells at the burrow entrance - when carrying out surveys on Walthamstow Marshes and similarly, I once saw cockles at the entrance of water vole burrows (verified by an expert) on a site in Tilbury.

[vole-woman]

That's interesting about the cockles. The fish incident is recorded in a book by S R Ryder, and refers to a pregnant female water vole who the author thought might be in need of extra protein. I'm beginning to suspect they're slightly less vegetarian than we think!

If the area does turn out to be inhabited by water voles, Howard, the landowners need to know as w-vs are a protected species. You can ultimately go to prison for interfering with them. That doesn't mean the banks can't be maintained, but there are ways of dealing with overgrown vegetation and other management work which will only have a small impact on the voles.

[Howard Field]

You've guessed right, Kate, about the pond not being mine. It was dug out in the flood plain, a few years ago now, because my neighbour and his wife are very keen on wildlife. When I moved 'next door' to this idyllic spot of Worcestershire three years ago, he even lent me his small mechanical digger to dig out a pond of my own, albeit a rather smaller one. Being an retired biology teacher / ecologist, I hardly needed any extra bidding. His pond is a haven to wild-life where, like mine, it has become colonised quite naturally with small fish [sticklebacks] during flooding, which happens usually about twice a year; planarian worms; a myriad of insects, crustaceans & molluscs; newts; frogs; moorhens, which breed in amongst the reeds; mallard ducks; willow tits; kingfishers, about which I am very jealous; and now water-voles, maybe, about which our neighbours are absolutely delighted --- he's even thinking of fixing up a discrete camera for observation purposes. We also have a 'clapham junction' of a badger sett on waste land in the middle of our quiet settlement. It's so WONDERFUL, literally! No worries, then, about not wanting to protect the wild-life.