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

[vole-woman]

Just had a massive long reply fro Rob Strachan! Need to print it out, read and digest. Thanks everyone for your input.

[Hobjob]

So, two species were lumped in the 50s.

I'd bet a few quid on them being split any time soon - probably when someone can afford to do the genetics. Then there is a PhD to be done on describing the resulting hybrids .........

Cynic - Moi?

Interesting thread though - thanks.

[vole-woman]

Here is Rob Strachan's reply:


Hi Kate,

It is a good question and one that has puzzled naturalists through the ages since the species were given scientific names...

Back in 1693 the eminent English Zoologist described a Water Rat and named it Mus major aquaticus and this species was later reclassified by Carl Linnaeus in 1758 as Mus amphibius in his Systema Naturae, while also describing a burrowing large vole as Mus terrestris in Sweden. In about 1770 Gilbert White then wrote a comment that Mus amphibius and Mus terrestris were in fact the same species but with differing behavioural habits. In 1790s a French zoologist reclassified them into a new Genus Arvicola to distinquish them from true mice (Mus) and a full review of species and names was done by an American Zoologist GS Miller in 1912 - he decided there were in fact 6 water voles in Europe and 2 species in North America. Arvicola amphibius (Britain), A.sapidus (Spain and southern France), A.scherman (north central Europe) A.terrestris (Norway + Sweden), A. musigrani and A.italicus (both in Italy).
A study of water vole Chromosomes in the 1970s lumped water voles in to 2 full species in Europe (A.terrestris and A.sapidus) and a third full species in North America (A. richardsonii). Each with a number of sub-species. Thus the semi-aquatic and bigger British water vole has been generally known as Arvicola terrestris amphibius and the smaller, more fossorial (meadow living burrowing form) water vole of Europe as Arvicola terrestris scherman.

However, with the advances of modern DNA techniques the situation has again been muddied and 6 or 7 species/subspecies are thought to occur across Europe. Water voles in lowland England and Wales (and eastern and northern Europe) are now being called Arvicola amphibius and water voles in Scotland and upland parts of northern England and Wales (and southern and western Europe) are being called Arvicola terrestris.

Wherever they occur the species is still principally a burrowing animal that favours the riparian zone of flood plains, fens, wet meadows and water bodies. Water is a fantastic means of escape from predators and also provides an easy way of patrolling a territory.

When water voles are living in runs and tunnels of floodplains, grasslands or alpine meadows they are probably at risk from many predators and as such are likely to survive best in habitats that provide abundant cover by way of tussocky grasses, etc.. These exclusively burrowing water voles also rarely exceed 250g in weight while the aquatic ones can reach 350g body weight.

I hope you find the comments above have answered your question Many regards Rob

[vole-woman]

Isn't he great?