by Matt Walker
Editor, Earth News
A potential victim of the pox
An outbreak of pox virus among red squirrels could ultimately help save the species from dying out in the UK.
Scientists are embarking on a study of an epidemic of squirrelpox virus among red squirrels at Formby near Liverpool.
The study should help uncover how the squirrelpox virus is spread between grey and red squirrels and why reds are particularly vulnerable to it.
In turn, that may help scientists stem the spread of the disease and ensure the red squirrel's long-term survival.
The exact causes of the catastrophic decline in red squirrel numbers in the UK are hard to pin down.
Scientists believe the larger and more aggressive grey squirrels have been able to out-compete their red cousins for resources.
But they also think that a deadly pox that appeared soon after the greys arrived has also been responsible for the decline.
Around 160,000 red squirrels remain in the UK, compared to 2.5 million grey squirrels
Remaining havens include Formby on the Sefton Coast, the Lake District, Brownsea Island in Dorset, parts of Northern Ireland and Scotland and the Isle of Wight
Squirrelpox can kill red squirrels within weeks
The virus is carried by both grey and red squirrels, but while greys are relatively unaffected by it, the disease can be lethal to reds.
In 2007, a major outbreak of the virus caused a 90% fall in the number of red squirrels living around Formby, on the Sefton coast of Lancashire.
That was despite woodlands in the area being designated part of the UK's third National Red Squirrel Refuge, with a 5km buffer zone being set up around the trees to prevent grey squirrels intruding.
The disease continues to affect the remaining squirrels as well as others along the coast.
Scientists based at the University of Liverpool are now embarking on a four-year project to study these squirrels to find out more about the action and spread of the disease.
By repeatedly monitoring the squirrels, the researchers hope to find out exactly how the squirrels become infected and whether any survivors have developed immunity to the disease.
The study will also determine how fast the infection progresses and what might halt its spread.
"Formby is on the front line in the battle for survival between red and grey squirrels," says Professor Mike Begon from the School of Biological Sciences at the University of Liverpool.
"We are hopeful this new research will help us understand the dynamics of squirrelpox virus and how that knowledge can be used to ensure the long term survival of red squirrels across the UK."
The research is being funded by the National Trust and the National Environment Research Council.