The pine marten (Martes martes) is recovering across Scotland and parts of Wales and Ireland following centuries of persecution and habitat loss. As mustelid predators recolonizing their former range, pine martens are affecting ecosystems in complex waysâincluding surprisingly positive effects on red squirrel conservation through their predation of grey squirrels.
UK pine marten populations crashed through the 19th and early 20th centuries due to trapping, poisoning, and deforestation. Scottish populations survived and have recovered substantially with legal protection. Reintroduction programs in Wales (since 2015) and England (Northumberland, since 2019) are establishing new populations through translocations of Scottish individuals.
Translocation welfare requires: thorough health screening, appropriate quarantine, soft-release methods (acclimatization enclosures), minimizing handling stress through skilled capture techniques, post-release monitoring via GPS collars, and supplementary feeding during establishment. Translocation mortality is a welfare cost that must be weighed against population benefit.
Pine martens preferentially predate grey squirrelsâlarger, slower, and less familiar with marten predation riskâover red squirrels, which evolved alongside mustelid predators and retain appropriate avoidance behaviors. Areas with recovering pine marten populations show declining grey squirrel density and recovering red squirrelsâan unexpected welfare and conservation benefit.
Pine martens occasionally predate gamebird eggs and chicks, creating conflict with game management. Legal protection prevents lethal control, requiring non-lethal deterrence (nest protection, predator-proof release pens). Building coexistence frameworks that address legitimate management concerns while maintaining legal protection is essential for continued recovery.
Part of the Animal Welfare Hub â 2375+ pages of evidence-based animal welfare information.