This is a key question for conservationists, as Britain’s native red squirrels slowly succumb to alien greys. It is also a hot topic among foresters desperate to reduce the number of trees lost to the bark-stripping antics of these American invaders.
There is some cautious optimism that the pine marten, a native carnivore, may save the day. Recent research in Ireland, together with anecdotal evidence from Scotland, suggests that where pine martens are thriving, red squirrel numbers have increased and those of greys have decreased.
Grey squirrels are larger and heavier than their red cousins and spend much more time on the ground, making them easier prey for hungry pine martens. Dietary studies have also shown that red squirrels are rarely targeted.
The pine marten is doing well in Scotland and Ireland, and is on the increase in Wales. It is possible that the grey’s days are numbered; time will tell.
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