How pine martens help red squirrels in battle with greys – leader comment

Red squirrels have evolved to be sensibly afraid of pine martens, while the greys have not.

Pine martens induce fear in red squirrels which means they are harder to catch, while they greys are, unfortunately for them, not quite as scared (Picture: Josh Twinning/PA Wire )

The demise of the red squirrel once seemed like only a matter of time, given the seemingly relentless advance of their American cousins, the greys.

However, following the reintroduction of pine martens, a predator of both species, researchers began to notice the reds seemed to be doing better than expected.

Now a new study has discovered one reason why: the reds, having evolved over centuries to live alongside pine martens, have learned to be scared of them. Very scared. In fact, the slightest sniff of ‘eau de marten’ was enough to make the reds scarper.

The greys, on the other hand, lack the same innate sense of justifiable fear meaning they are, in the words of the scientists, “highly vulnerable to predation”.

Humans have killed off many leading predators and we are only just discovering how significant the effects of the absence of these animals can be on the wider eco-system.

It’s a bit of shame for the blameless greys, but if the return of pine martens helps save the reds, that’s another reason to welcome them back.