Pine martens can help in the conservation of red squirrels by reversing the spread of grey squirrel populations, a study has shown.

Scientists used DNA forensics to show how pine martens suppress grey squirrel populations in Scotland.

Scientists, from the University of Aberdeen, Waterford Institute of Technology and the University of Massachusetts Amhers, claim this is good news for both squirrel conservation efforts and the timber growing industry.

The research took place in the Scottish Borders, where pine martens have started to recolonise, Central Scotland, where this an established population and in the Scottish Highlands.

Multi-species feeders were deployed throughout the regions, baited with a mixture of nuts and seeds.

Sticky patches placed under the lid collected hair samples from squirrels and pine martens that took the bait, and trail cameras were used to improve detectability.

The study built on a 2014 study, which suggested that pine martens may be responsible for the decline of grey squirrels in Ireland, and confirmed that the relationship between red and grey squirrels is altered in the presence of a native predator.

Dr Sheehy said: "Our study has confirmed that exposure to pine martens has a strong negative effect on grey squirrel populations, whereas the opposite effect was observed in red squirrel populations who actually benefited from exposure to martens.

"Our evidence that, in addition to their intrinsic value, pine martens provide an ecosystem service by suppressing invasive grey squirrel populations is good news for both red squirrel conservation efforts and the timber growing industry, due to the detrimental impact of the invasive grey squirrel on both.

"The pine marten is already heavily suppressing grey squirrel populations where they are well established, and presumably this influence will spread as the pine marten's range expands southwards through Scotland and into the North of England but this is likely to be a slow and very gradual process."