Kielder Forest in Northumberland, England, is home to birds of prey and red squirrels. Around 90 years ago, it was also home to the pine marten (Martes martes), a cute but deadly predator. The 1.6-foot (0.5 meters) long member of the weasel family was driven to extinction in England by 1926 because gamekeepers wanted to secure the safety of their game birds, according to The Guardian.
The martens thrived in Scotland, however, and the animals appear to be crossing back into England. A pine marten was spotted in Kielder Forest by John Hartshorne, a volunteer who monitors the red squirrel population in the forest, part of an effort to stop grey squirrels from further invading the red squirrels' territory.
"I was getting loads of great shots of red squirrels and then thought, 'Oooh, what was that?' I zoomed in and for a moment or two, I thought a badger had got up to the baited feeder but focusing in it was incontrovertibly a pine marten, which is superb," he told The Guardian.
"We know that there are pine marten around in Northumberland from anecdote, but we've been waiting for a clear picture of evidence that they are here."
The enemy of my enemy is my friend
The pine marten is one of the animals receiving a helping hand from Back from the Brink, a consortium of conservation groups working together to help save 20 species from extinction in England. Their efforts are aimed at helping the pine marten and other at-risk species, like the aforementioned red squirrel.
Red squirrels are threatened by invasive gray squirrels, which outcompete the native squirrels for food and pass on a deadly virus. Martens keep gray squirrel numbers in check, especially since the invasive critters aren't used to having a predator like the pine marten around. A 2018 student found that the presence of pine martens can be enough to push the gray squirrel population out of an area.
So the pine marten returning to Kielder is a win-win: The pine marten returns to part of its historic range and in doing so, helps red squirrels continue to survive.
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