Pine martens are recovering in Scotland and being reintroduced to Wales and England. Their return benefits forest ecosystems and has surprising positive effects on grey squirrel management.
Pine marten reintroduction is largely a welfare-positive conservation story. Individuals used in reintroductions are wild-caught in Scotland, which involves capture stress, health assessment, and transport - all managed to minimise suffering by trained ecologists. The unexpected benefit for red squirrel conservation is significant from a welfare perspective: marten recovery naturally suppresses grey squirrels in ways that benefit red squirrel welfare without requiring systematic culling. The main welfare concerns for martens themselves are road casualties and illegal persecution, both of which remain threats as populations expand into new areas.