Red squirrel populations are put at risk by conifer tree plantations that are intended to help boost their numbers, a study has found.

Conifer plantations have long been considered an ideal habitat to support red squirrel numbers, partly because they are not favoured by their grey rivals.

However, a new study has found it is the presence of pine martens, which prey on grey squirrels, that is more likely to impact their numbers.

Pine martens were once on the brink of extinction in the UK, but their numbers have recovered significantly in recent years.

As their numbers have increased, conifer plantations have become more dangerous for red squirrels because without their grey relatives, they become prey for pine martens, researchers believe.

In addition, single species plantations do not give red squirrels any places to hide, as they would in a diverse forest, said Dr Joshua P Twining, the study’s lead author from Queen’s University Belfast. 

“Timber plantations are often promoted as being beneficial to red squirrel conservation, but our results show that they will have a detrimental effect on the species in the future,” Mr Twining said.

“If you think about an old growth woodland or wood that’s allowed to grow over 30 years old, you’re going to get lots of snags and gnarls and these small refuges that squirrels are going to be able to hide in,” he said. 

“The distinction is between natural and manmade habitats. Natural habitats are structurally complex while manmade habitats are simplified and uniform.”

Conifer woodlands are planted foremost for commercial purposes as timber plantations, but have also been promoted as a positive habitat for the red squirrel, considered an endangered species.