Longish article here:
Tufty's saviour to the rescue
Pine marten numbers swell, killing off the grey interlopers who ousted the red squirrel
By Jeremy Watson
THEY have been vilified as a pest, persecuted for centuries and hunted for their fur.
But now one of Scotland's native animals is attracting a new body of support for its role as a potential saviour of the red squirrel.
The pine marten, a small mammal once prolific throughout the country's woodlands, only existed in remote pockets in the far north of Scotland a century ago.
As it has spread south again, however, it has come into contact with American grey squirrels which are taking over the territory of the native reds, now a threatened species.
Forestry researchers have now found that where the two species have moved on to the same ground, grey squirrel numbers have gone into reverse.
They believe that carnivorous pine martens prey on greys, which, unlike reds, mainly forage for food on the forest floor. But they are unable to catch the faster, lighter native species, which normally inhabit the treetops.
They are now calling for habitats for pine martens to be created to help stop the invasion of the greys in its tracks. Red squirrels are now one of Scotland's most endangered species, largely due to the bigger, more aggressive greys moving into their former territory.
The pine marten effect has been observed in woodlands in Perthshire, near Pitlochry and Aberfeldy, and published in a paper for the journal of the Royal Scottish Forestry Society.
Rob Coope, the Forestry Commission's Tayside region biodiversity manager, said: "Pine martens are opportunistic animals who will exploit any new food source that moves into their territory.
"Grey squirrels are a big threat to red squirrels, but what we have noticed is that in areas where pine martens are active, grey numbers go down and they almost disappear.
"Their march up the country has been pretty relentless, but in these areas it had been halted.
"We tried to think of reasons for this happening, and the theory is that expanding pine marten populations come up against expanding grey squirrel populations. Colleagues in Ireland feel they have seen the same thing happening."
Coope suggests that the answer to why pine martens hunt greys rather than reds is that the American invader mainly hunts for its food at ground level.
"We know that pine martens feed mainly on the ground and we know that greys spend more time on the ground than reds," he said.
"Reds tend to be in the treetops eating seeds from pine cones, whereas greys will run around on the forest floor looking for acorns and beech nuts. That's when they come into contact with pine martens.
"So it may be that in areas that are poor habitats for grey squirrels, pine marten predation tips the balance in favour of the red."
Pine martens, which grow to the size of an adult cat with a bushy tail, are part of the weasel family of animals, native to Northern Europe. Its fur is usually light to dark brown and grows longer and silkier during the winter months. It has a cream to yellow-coloured 'bib' marking on its throat.
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