It was not so long ago that naturalists were predicting that the Water Vole would be extinct in the United Kingdom within a few years. Predation by the North American Mink, loss of habitat and pollution seemed to be the main culprits.
The much loved small mammal, immortalized in fiction as Ratty (
left) in Kenneth Grahame’s
Wind in the Willows, seemed destined for the history books. It was given protected status as late as 2008 - a legislative moved considered by many to be too little too late.
Yet just a few years after their dire predictions it seems that the water vole is back from the brink, testimony to the help it has received from conservationists.
Thriving colonies of over two thousand now exist in several places in the UK. Less than ten years ago, surveys of the same places revealed only a scattering of water voles, less than twenty in each location. If those numbers have made you raise an eyebrow you may not know just how fecund a water vole can be. Left to her own devices a female can produce up to
thirty young in a season with up to eight baby voles per litter. So, what did the environmentalists do to aid such a dramatic come back for this semi-aquatic rodent?
The main element in this resurgence has not necessarily been just making the environment itself more welcoming to the water vole. The water vole renaissance has been due to ensuring that its main predator, the North American Mink, remained absent from these protected areas. Take a look at water vole enemy number one.
The North American Mink (
above) is an invited but invasive species – which needs some explanation. It was introduced in to the UK in the 1920s and bred to provide the demand for fur coats. Some escaped or were released (it really doesn’t matter which if you are a water vole) and quickly bred and spread. Unfortunately for the water vole, the agile mink, a beautiful yet ferocious killing machine, found them to be the ideal diet for survival in its new country.
As a result the numbers plummeted. Before 1960 there were more than 8 million water voles in the UK. By the turn of the century this had declined to just a few hundred thousand. The only healthy populations were in the conurbations of London and Birmingham where the North American mink had not reached or was controlled by local councils because of its potential threat to children.
Another aspect of the conservation of water voles is the effort to increase its reed bed habitats in and around rivers. When properly preserved or restored these reed beds can support a huge network of water voles, known as a metapopulation. This is effectively what has happened at the three sites (two in Yorkshire and one in Gloucestershire).
Huge efforts have been made by the Wildfowl and Wetlands Trust and the Environment Agency to ensure this ‘Ratty renaissance’. In some places this has coincided with the return of the European otter (
above, taken in their element, Conwy Valley, Wales) which has helped the water vole population out too. The reason? There is nothing more a European otter loves for its dinner than a North American mink!
One battle may have been won but the war is far from over. The North American mink still thrives in large numbers across a large part of the UK and its eradication is far from certain. Of course, the water vole has always had enemies such as owls, stoats and herons (who can swallow one down in a single gulp), but today at least we can celebrate the at least partial return of ‘Ratty’ to the riverbank.
