Arvicola amphibius - The Water Vole

 The Water Vole

By Lachlan Royle 

Distribution and Population Dynamics 

A rather shaky photo of a water vole on the UEA river 

The water vole is perhaps the trickiest mammal to lay eyes upon not only on UEA's campus but also across the UK, a very shy and sweet rodent its population has plummeted in the last few decades due to one large factor; the American mink. The current population of the UK is roughly 130,000 individuals but this has seen a 94% decrease in sites it has been previously seen, in 1990 just 34 years ago the population was estimated to sit at 7.3 million. No other mammal in the British Isles has witnessed a population decline even close to that of the water voles in that time. They can still however be found in most counties form Cornwall up to North East Scotland, but to actually sight one now is considered a rarity.

Behaviour

Water voles often surprise people with their size, being a member of the vole family they are not thought of as large. Whilst not compared to many other species, comparatively within their family they are very large, so much so they are sometimes confused with brown rats. They take to grassy banks on slow moving rivers or marshland. Here they dig burrows into the side of the bank, often as a form of protection they dig the entrance to these burrows underwater to deter some predators. They are diurnal and do their feeding and foraging throughout the day, often instead of seeing water voles you will hear the distinctive sound of them dropping into the water to avoid you when they detect your presence. There are active conservation efforts particularly in London aiming to restore water vole populations across the UK. Hopefully this fascinating mammal can make a comeback in this country in years to come.