April 23, 2009

Grey Vs. Red: An Ongoing Battle

Several organizations are vowing to support the revitalization of the dwindling red squirrel population in Europe.

The red squirrel used to dominate the countryside, with more than 3.5 million strong. But now, only about 150,000 remain. Of the remaining, about 75 percent roam the wild in Scotland, and the rest are in protection in northern England.

Organizations blame the red squirrel's American cousin, the grey squirrel, for the population decline.

Grey squirrels were brought to country estates in 1876. Their larger size and thicker fur helped them quickly become the dominating breed of squirrel. In 1930, the import of grey squirrels into the wild became illegal for fear of completely wiping out the red squirrel population.

The major blow to the red squirrel population came from a squirrel pox virus carried by the grey population. The virus results in death for red squirrels, meanwhile greys are immune.

"It can take only one grey squirrel to introduce this virus to a local population of red squirrels, and then the virus can spread throughout the reds with devastating effect," says the group Save our Squirrels (SOS).

As a result of the virus and encroachment by the grey squirrel population, red squirrels have been a protected species since 1981.

According to a study released earlier this month, red squirrels are making a comeback in Cumbria, Northumberland and regions of Wales after 20 years of decline.

Officials at the Red Squirrel Survival Trust said the evidence shows that the red squirrel population makes a faster rebound when greys are trapped and killed.

"Ten years ago there were fewer than 40 red squirrels on the island of Anglesey, and their prospects were bleak," Dr Craig Shuttleworth, Project Director of Friends of the Anglesey Red Squirrels and RSST adviser, told the UK's Telegraph.

"However, through a strong local partnership, grey squirrels have almost completely been removed from the island, and the red squirrel population has increased to 300. Significantly they have spread from the conifer trees to the broadleaf areas "“ showing that reds are happy in a whole variety of habitats providing they are untroubled by greys. Anglesey has turned the grey tide."

The RSPP estimates that 22,287 squirrels have been killed since January 2007.

"We only call ourselves the Red Squirrel Protection Partnership because if we called it the Grey Squirrel Annihilation League people might be a bit less sympathetic," supporter Baron Rupert Mitford told the UK's Guardian newspaper.

Conversely, the Saving Scotland's Red Squirrels project is aimed at protecting the habitat of red squirrels while keeping the greys under control.

Now, many experts have their eye on a new challenger: the black squirrel.

Alison Thomas, a geneticist at Anglia Ruskin University in Cambridge, conducted a study to show that there are about 25,000 black squirrels in existence, but "the black mutation gene has a dominant aspect which explains their rapid increase," she told AFP.


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