The trust is a partner in the Pine Marten Recovery Project, which aims to restore viable populations to Wales and England. Last year it oversaw the first translocation of pine martens from Scotland to mid Wales. Their reintroduction appears to have a side benefit of controlling grey squirrel numbers, Wilson explained. "Greys will strip bark off young trees in the winter, but there are fewer of them where pine martens are present. People are asking me: 'Where can I rent one?' As a woodland charity we have an interest in this too."
He added that native red squirrels, which are lighter and more agile so able to avoid martens, "are better for trees because they hibernate so don't get hungry in the winter - they leave trees alone", and also benefit from greys being controlled.
On another candidate species for reintroduction, he added: "Lynx could keep deer numbers down, including muntjac, and so have knock-on beneficial effects on entire ecosystems." The Woodland Trust was among those consulted on the Lynx UK Trust's proposed five-year trial reintroduction of the Eurasian lynx to the Kielder Forest and Scottish Borders area.
An online survey in March showed support for the proposal among the nearly 10,000 respondents at more than 90 per cent. The proposal's net benefit - reductions in crop and forestry damage by deer plus the creation of tourism opportunities - has been estimated at more than £30m. The risk to sheep farming has been described as "negligible".