One of Britain's best-loved mammals, the red squirrel, is to be given a lifeline to help it to withstand the onward march of its grey cousin.

The plan should enable them to live and breed undisturbed, and possibly to grow in numbers.

It is being launched by the wildlife trusts of Durham and Northumberland, in what they call "an attempt to save the north-east's last remaining colonies of red squirrels".

The species was once widespread throughout the British Isles, but now there are only 160,000, most of them in Scotland. The numbers in Northern Ireland are not known. The number in England is about 30,000, with roughly half of those in the north-east.

Best chance

The two trusts have identified eight refuges, and another 17 are being proposed at a meeting on 15 October of conservation groups, private landowners, forest managers and local authorities.

The refuges are being chosen for several factors, including the type and size of the woodland, the ease of defending it, and the nature of the surrounding landscape.

Jason Reynolds works on red squirrel conservation for the trusts. He said: "It is only in the past few years that we have discovered the specific type of habitat where they have the best chance of survival.

"Reds prefer conifer woodland planted with particular varieties of trees, for example Scots pine, Norway spruce and larch. Our aim is to identify the best sites and ensure they are managed in a way which is attractive to them. Habitat management is central to the survival of the red squirrel."

Woodland fragmentation

Liz Woznicki of the Wildlife Trusts, the body which co-ordinates the work of the 47 county trusts, told BBC News Online: "No-one knew earlier what sort of habitat the reds preferred, because no-one had done enough research.

"It's only recently that we've realised how precarious their plight is, and how much research is needed."

The red squirrels' decline is blamed on several factors, including disease, the loss and fragmentation of woodlands, and competition by the greys.

Grey squirrels were introduced to the UK in the 19th century, and now number more than 2.5 million animals. They can exploit deciduous woodlands better than the reds, and their breeding prospects and adult survival rates are better there.

In conifer woods, though, the reds' survival chances are much higher.