GREY squirrels spotted in a red conservation area in the Lake District can clear out the natives within 'days'.

That's the warning after hikers using the new wildlife trail allowing access through Elleray Woods to Orrest Head took photographs of greys in the area.

Rob Milligan said he saw two greys on Sunday 29 September, snapping a photo of one in the woods. 

Geoff Hetherington, chairman of the conservation group Westmorland Red Squirrels, said: "We have been inundated with grey squirrels this year." 

He blamed this on a mild winter leading to an abundance of food resources. Greys can also breed multiple times a year unlike reds, Geoff said. 

"People insist on feeding them," Geoff added. The group is finding it 'very difficult' to drive back grey populations through culling by shooting or trapping. It is illegal to release grey squirrels without a licence, according to the Wildlife and Countryside Act 1981, meaning that conservationists cannot simply move them to a new area.

When asked how quickly grey squirrels can drive out reds, Geoff said 'within a matter of days, could be weeks.' 

Red squirrel populations are under threat from their non-native cousinsRed squirrel populations are under threat from their non-native cousins (Image: Danny Lawson/PA Wire)

Greys were introduced to England in the late 1870s from America and have since decimated the native reds. They out-compete reds for food and transmit lethal 'squirrelpox' which only the greys have natural immunity for. 

Once found throughout the nation, red populations are now contained to parts of northern England - particularly the Lake District. 

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The grey numbers are a 'big problem' in towns such as Kendal and Windermere, according to Geoff. This is despite red squirrels being spotted for the first time in 20 years in the Lune Valley near Kirkby Lonsdale in April. 

In terms of red populations shrinking and rising again, Geoff said 'this happens quite a lot.' 

He added the group needs more volunteers, including in administration roles, to tackle the problem. 

Geoff claims that even squirrel-proof bird feeders can be broken into by greys. He asked residents not to feed the 'invasive species.'