Why the difference in behaviour between European water voles and UK ones?

[vole-woman]

Does anyone know? I was asked on a course yesterday and I didn't have an answer to why UK w-vs always live by water, and ones in Europe make their homes in fields and orchards, making little hills like moles.

[STYRBJORN]

The difference is that European W.V.s carry identity cards.

Ric

[Adam Cheeseman]

Hi V-W

Try this chap

Derek Gow Consultancy | Specialists in Water Vole Conservation l Useful Resources

met him several times in relation to introduction projects. He should know.

Cheers,

Adam

[vole-woman]

He's lovely, isn't he? I've spoken to him on the phone re flooding. Other likely experts I could approach are Xavier Lambin and Rob Strachan. I just wondered whether anyone here happened to know.

[poschiavanus]

Originally Posted by vole-woman

Does anyone know? I was asked on a course yesterday and I didn't have an answer to why UK w-vs always live by water, and ones in Europe make their homes in fields and orchards, making little hills like moles.

Not strictly true, there are relict populations of fossorial water voles on various Scottish Islands, such as Jura. See this SNH page.

Until relatively recently (mid 1950s IIRC) the two ecotypes were regarded as separate species (Arvicola terrestris and Arvicola amphibius), but since then have been lumped. The scientific name seems to be still subject to argument because the two original descriptions were on the same page of Systema Naturae.

There doesn't seem to be anything about this in the Handbook of British Mammals.

There is a good account in Die Saugetiere Baden-Wurttembergs (a very good source of info about non-marine British Mammals ), which treats the fossorial form as a separate sub-species A. t. scherman. It has a nice table showing the differences between its diggings and those of moles. Food plants given for the fossorial form include: wild plants such as Hogweed, Dandelion, Wild Carrot, Salisfy, Broad-leaved Dock, Cow Parsley, Plantains, Buttercups, Yarrow; crops : Sunflower,Jerusalem Artichoke, Potatoes, Lucerne, Clovers; cultivated vegetables; orchard trees, mainly Apple; wild trees, pretty much any sapling broad-leaved tree and larches; garden plants. Much of the literature is concerned with the pest status of this form in countries where it is common. There do seem to be some physical differences between the two, with the fossorial form being smaller, lighter and with a relatively shorter snout.

I've found a short article which I remember reading a while back in a newsletter of the Derbyshire Mammal Group.

I'd be surprised if there isn't more on the genetics of the different populations as there has been a considerable amount of work population genetics of rodents both in Britain (island forms of mice and voles, Sam Berry) and elsewhere in Europe (e.g., Francois Bonhomme on mice).

[Adam Cheeseman]

Originally Posted by vole-woman

He's lovely, isn't he? I've spoken to him on the phone re flooding. Other likely experts I could approach are Xavier Lambin and Rob Strachan. I just wondered whether anyone here happened to know.

Rob and Chris Strachan may well know. Very nice guys who probably know as much, if not more, than Derek. I was at the London wetland centre release with them. They both paid several visits to Bedfont with regards our introduction. Afraid I don't have any contacts for them.

Cheers,

Adam

[vole-woman]

Wow, thanks!

[vole-woman]

So if I've read the Derbyshire newsletter right, we used to have land-living water voles too (and we still have a few on Jura) but they sound as though they're a different sub-species as they're larger? Is that correct?

[poschiavanus]

There's a paper in J. Zool. about the genetics (DOI: 10.1017/S0952836902003321 if you've got access to JSTOR).

As for size, the german book has a clear description:

Die groessten and schwersten Schermaeuse mit ueber 200 mm K-R-L und bis ueber 300g Gewicht leben in England.

"The largest and heaviest water voles, with Crown-Rump length of over 200 mm and weights to greater than 300 g live in England [probably meaning Great Britain."

For comparison the population they quote sampled from around Stuttgart in the 1950s (not specifically from either subspecies) had C-R lengths of 149-178 and weights from 78-117 g. In other words significantly smaller than British w-vs. The SNH site suggests that British w-vs are from two different glacial refugia with Scottish ones from Iberia, and English ones from S-E. Europe.

It seems to get more complicated still looking at the IUCN page. Here the subspecies sherman has been raised to specific rank, but this still leaves 3 (or more) distinct populations in A. terrestris/amphibious.

The abstract of one last paper more or less says that speciation in subgenus Microtus is on-going and/or poorly understood.

Looks like there's loads more to learn about Water Voles and there may be a few surprises down the line.

P.S. Sam Berry's New Naturalist Inheritance and Natural History has a lot about island populations of small mammals in Britain.

[vole-woman]

"The SNH site suggests that British w-vs are from two different glacial refugia with Scottish ones from Iberia, and English ones from S-E. Europe."


That little bit I knew, but not the rest. Thanks for the ref! So the European fossorial ones are a different sub species (or species?) from our larger aquatic ones?