Capercaillie: Scotland's most threatened bird at the edge of extinction

Game & Wildlife Conservation Trust says that when surveys commenced in 1991, capercaillie numbered approximately 2,200 birds, spread from Argyll and Perthshire to the south and west Aberdeenshire in the east and Ross-shire in the north.

Just five years ago a national survey revealed there may be as few as 1,114 individuals.

Now, the GWCT say perhaps only 300 - 400 birds remain, with 90% confined to one area of Strathspey in Inverness-shire.

GWCT is now calling for urgent policy and practical action to easer the continued pressure on the popular native bird, whose Gaelic name translates as the “Horse of the Woods”.

The world's largest grouse, and an iconic species of old pinewoods, was reintroduced to Scotland in 1837 from Swedish stock after becoming extinct the previous century.

A steep decline in recent years has seen the largest member of the grouse family included on the “red-list” of species of highest conservation concern.

The Trust say the bird is now "living in fragments" of the once widespread Caledonian Forest, where it is in "severe trouble".

Picture: Arterra/Universal Images Group via Getty Images (Image: Picture: Arterra/Universal Images Group via Getty Images)

Sharp declines are occurring because fewer chicks hatch and survive in Scotland than elsewhere in their European and Russian range.

In August, the Trust completed its 33rd consecutive year of capercaillie brood surveys and it discovere "a continued decline in breeding success over time".

GWCT research has shown that capercaillie breed better in years when June weather is dry and warm, and in forests where predators such as carrion crow and pine marten are fewer.

his year, despite good weather, the survey found only 0.4 chicks fledged per female, below the 0.6 chicks needed to maintain numbers.

This was the fifth consecutive year when insufficient chicks fledged, thus hastening the decline, says the Trust.

Despite well-intentioned conservation programmes to improve capercaillie habitat, extinction "seems likely within the next 30 to 50 years", it said.

Earlier this year, scientific advisors to NatureScot reviewed causes of decline and urged four immediate management actions.

To increase breeding success, they recommended reducing the effect of predators by lethally controlling foxes and crows and translocating legally protected pine martens from capercaillie forests.

It also provided remaining predators with alternative diversionary food.

The Trust says NatureScot is still to address the need for proven, immediately available alternatives to protect capercaillie broods.

Lead surveyor Dr David Baines, GWCT’s head of upland research, commented: “The end is nigh for capercaillie unless we quickly turn around the low chick survival. Pine martens have increased in recent decades and are known to consume capercaillie eggs and chicks. Their licensed removal from key capercaillie strongholds is urgently required to help avoid species extinction.”

The capercaillie is the world’s largest grouse. Males - unmistakable with their slate grey plumage, blue sheen head and bright red eye ring - can reach around 90cm in length and 14lbs in weight. Females are smaller with brown and chestnut-red feathers and fan-shaped tail.

Despite their size, capercaillie are fairly elusive, often sitting quietly in pine trees or on the forest floor.

In spring, however, they can be seen gathering at communal “leks” -- the males’ courtship display in the hope of attracting a mate.

There were around 20,000 birds across Scotland in 1970, but a survey conducted by RSPB Scotland during the winte of 2015/16 revealed just 1,114 birds - around half the size of the population in 1993, when the first survey estimated there were 2,200.

Will Anderson, chief executive of Seafield and Strathspey Estates who hosted this year’s survey added: “We have been managing and extending our forests to benefit capercaillie for over 30 years and it would appear that neither habitat extent nor quality is limiting their numbers. We are concerned that in a year where weather is also unlikely to be a limiting factor, we have such poor brood numbers.

"We carry out legal predator control but there is no mechanism available to us for managing the impacts of protected predators and we await the response to a ministerial briefing, following a NatureScot report, for guidance on what further steps we can take to halt the decline of this important component of our pinewood habitats.”