The findings, published earlier this year in the European Journal of Wildlife Research, present a hopeful outlook for this endangered species, as its adaptability might be key to its future success providing continued legal protection, and provision of suitable habitat.

The results of this research, funded by wildlife charity People’s Trust for Endangered Species (PTES), show that despite their diets differing in each location, the eating habits of pine martens remained the same: they focused on a few staple food items and supplemented these throughout the year with seasonally available treats. The seasonal fluctuations in their diet was already documented, but the fact that every population across the range followed the same pattern, was not.

Joshua Twining, PhD Student from the School of Biological Sciences and the ecology end of IGFS, who led the project, explains: “The results are quite fascinating; it’s clear that pine martens are not only true opportunistic omnivores, but they’re also highly adaptable, and unlike many other species, they can switch their diet depending on what’s available around them at any given time.”

Surveys were conducted across the pine martens’ range in Northern Ireland, in a variety of habitats including semi natural broadleaf woodlands and coniferous plantations, as well as mixed habitats. Pine marten scats (droppings) were collected from different locations within their range on a monthly basis, to give a detailed picture of exactly what pine martens were eating.

Pine martens evidently have a sweet tooth, as the most commonly consumed food was fruit, with rowan, blackberries and bilberries all on the menu. These were consumed in abundance when available in late summer/autumn. Pine martens also appeared to target songbirds, shrews, grey squirrels and rabbits during each species’ specific breeding season, when they were at their most numerous and vulnerable. Whereas mice and insects – beetles, slugs, snails and earthworms – were eaten throughout the year and were staple foods, which pine martens supplemented with other food sources when available.

Rare and elusive, this enigmatic and magnificent member of the mustelid family are a native species to the British Isles and were once one of the most abundant predators in the country. Now, there are only an estimated 3,043 in Ireland and 8,900 in Great Britain, with approximately only 100 thought to be living in England.   

Nida Al-Fulaij, Grants Manager at PTES, says: “European pine martens are on the long road to recovery, and although they’re starting to recover in some areas, they still have a long way to go and remain one of the most threatened species in Britain. Less than 0.1% of Ireland and 2.4% of the U.K is made up of ancient woodland, so in order to help bring them back, we need to continue to conserve and manage our woodlands to ensure they provide suitable habitats for pine martens, as well as ensuring their legal protection is maintained. If these two aspects are continued, the newfound adaptability of their diet will enable them to survive.”

Nida continues: “Pine martens are an extremely important part of the ecosystem. Not only do they disperse seeds throughout the environments they live in, but they can also lower disease prevalence through removing carrion, as well as potentially playing a role in managing invasive species such as grey squirrels which in turn helps to bring back native species, such as red squirrels. Joshua’s work is a hugely positive step forward in helping us to understand pine martens, which hopefully will aid their recovery long term, too.”

To date PTES has awarded £6.5 million to research and conservation around the world and has funded 102 internships since 2002. The charity’s intern alumni includes conservationists working for wildlife NGOs, ecological consultancies, government agencies and universities, of which Joshua is one. Previous interns have developed software to identify different animals moving through wildlife mitigation tunnels, produced parkland management guidelines for rare invertebrate species and worked on DNA extraction and identification to help stop the trade in endangered wildlife.

Joshua concludes: “The gradual recovery of pine martens should be welcomed and cherished, as this wonderful and elusive mammal not only adds a little magic back into the wilds of Britain & Ireland, but as a small predator it’s key to returning our native ecosystems back to their natural order.”