Contraceptives to control pine marten proposed

Pine marten are among predators that eat capercaillie eggs

Pine martens could be lured into consuming contraceptives in an effort to control their numbers in parts of Scotland, it has been suggested.

The Game and Wildlife Conservation Trust said the measure would help protect one of the UK's rarest birds - capercaillie.

Pine marten are among animals that feed on the eggs of capercaillie.

The trust hopes to secure funding for a study into the effectiveness of contraceptive baits for pine marten.

Director Rory Kennedy said similar methods have been used to control non-native grey squirrels and feral goats in Wales.

• Cairngorms tourists urged not to seek out rare capercaillie

• Capercaillie at risk of extinction, survey finds

The trust works with conservationists, farmers and landowners in the management of game birds - such as grouse - and other wildlife in the countryside.

Mr Kennedy told the BBC's Good Morning Scotland programme reducing predation was one way of helping capercaillie.

He said: "There needs to be some sort of solution.

"We're looking at 20 to 30 years before capercaillie are likely become extinct in Scotland, and pine marten predation is one of the key aspects."

The trust has suggested using traps containing a contraceptive bait. A nut-based paste has been used for grey squirrels.

Mr Kennedy said trials might involve a bait filled with a dye which would show up in pine marten droppings, if they eat it.

He said culling pine martens was another possible method of control, but added that "no-one was leaping to that as the first option".

In the UK, capercaillie are only found in Scotland and fewer than 600 are thought to survive. The majority of capercaillie are found in the Cairngorms.

Conservationists warn capercaillie are on the brink of extincton

Both pine marten and capercaillie are protected species.

Habitat loss and persecution in the past led to dramatic population declines of pine marten. By the 1920s, they were only found in small areas of north-west Scotland, North Wales and the Lake District, according to the Mammal Society.

Conservation efforts have since seen their numbers increase in Scotland. There are thought to be up to 4,000 in Great Britain.

However Scotland's nature agency, NatureScot, said it recognised there was an urgent need to tackle threats to capercaillie.

A spokeswoman added: "Large-scale and well-managed forest restoration is the key conservation management tool to revive capercaillie populations."

The Cairngorms National Park Authority said: "Any proposal on contraception for pine martens would need to be assessed on its efficacy.

"As far as we are aware, no studies or scientific modelling has been carried out in relation to the use of contraceptive on pine martens to protect capercaillie, so it is difficult for us to advocate such an approach at this stage."