New research from the Game and Wildlife Conservation Trust (GWCT) has revealed a significant decline in the number of capercaillie in the Scottish Highlands. Numbers have almost halved in the past 10 years, with only 304 birds remaining in 2020. This is a stark contrast to the 580 birds that were present in 2010.
The largest grouse species in the world, capercaillie was once widespread across Scotland before becoming extinct in the 1780s. Reintroduction efforts in the 1830s saw the bird reappear in the Scottish Highlands, primarily in the Cairngorms National Park.
Despite legal protection in the UK, capercaillie have been in steady decline since the 1970s, when there were around 20,000 left in Scotland. National transect-based surveys conducted between 1992 and 1994 showed that only 2,200 birds were remaining and by 1999 this had dropped to 1,073.
The GWCT study, which ran over 10 years, recorded a 48% decrease in numbers, with the biggest decline occurring in the last five years.
Dr David Baines, Head of Uplands Research at GWCT, commented: “Declines are associated with a reduction in breeding success, which varies annually in relation to poor weather in June when chicks are growing and increased signs of predators such as pine marten in recent decades. This has happened despite efforts by land managers to improve habitat, and legally control foxes and crows. To reverse the trend and save the capercaillie from extinction, urgent action must be taken and conservation measures must be stepped up, including legal predator control, reducing predation risk by pine marten and further reducing the risk of bird collisions with deer fences.”
The research also found that breeding success fell from 1.24 chicks per female to 0.05 between 2010 and 2020 across five forests in Badenoch & Strathspey. This was linked to a 2.9% yearly decline in the number of males at spring leks.
According to Dr Baines, “Given the importance of low breeding success in the current decline and the variety of changing factors that influence annual success, the Trust firmly recommends that the previously comprehensive programme of brood monitoring should be restored to provide more robust estimates of productivity.”
The study showed that 83% of the remaining capercaillie males reside in the Cairngorms, emphasising the need for immediate conservation action in this area.
The devasting impact of collisions with deer fences on capercaillie and the related black grouse is now well established. Despite knowledge of the risks, many unmarked fences remain in place, with the study suggesting that these are still causing deaths in full-grown birds.
Dr Baines concluded: “By 2020, the risk of capercaillie extinction in Scotland was 23% after 25 years, 95% after 50 years and 100% after 100 years. When we removed deaths caused by fences from our analyses, the likelihood of extinction went right down to 0% after 25 years, 3% after 50 and 40% after 100 years, highlighting that fence removal must be an immediate and high priority to help save the capercaillie.”
Funded by the G & K Boyes Charitable Trust, this research marks a crucial step in the ongoing conservation efforts to save the capercaillie from extinction in Scotland. The GWCT is an independent wildlife conservation charity that has been providing research-led conservation for a thriving countryside since the 1930s.
Derick is an experienced reporter having held multiple senior roles for large publishers across Europe. Specialist subjects include small business and financial emerging markets.