This case study is taken from our Real Wilders book, which you can download here or you can buy a print copy here.
Pine martens are driving one of Scotland’s most majestic native birds to extinction. Current conservation efforts are failing, and a new approach is needed before it’s too late.
Recent downward trends in Scotland’s capercaillie are far more worrying than anything we have seen to date. There’s a serious risk that the birds will soon pass beyond the point of no return, and that’s when a number of factors will begin to cascade against the birds, driving them into extinction. Conservative estimates suggest that we could lose the capercaillie from Scotland in the next 20 to 30 years, but it’s hard to know for sure because scarcity has made the birds extremely hard to monitor. That makes it desperately difficult to help them at a time when they need support more than ever before.
Kinveachy Forest: A Last Stronghold in Peril
Kinveachy Forest is part of Seafield and Strathspey Estates, and is home to one of the last real strongholds for capercaillie in Scotland. While numbers remain viable at Kinveachy, the estate has not been immune to the declines that have struck so heavily elsewhere.
Head gamekeeper Ewan Archer currently manages a team doing everything they can to turn things around for these extraordinary woodland grouse, but he is well aware of the challenges they face on the estate. As he explains: “Capercaillie numbers have been dropping since the estimates of the 1970s, and our main aim now is simply to preserve this species from extinction. If we continue with the current lack of productivity, we’re very concerned that we’ll lose this bird altogether.”
Even in their heyday, the capercaillie population was closely monitored at Kinveachy. In-depth studies monitored numbers, productivity and lek counts, so the estate was better placed than many to identify real problems when numbers appeared to crash.
Ewan’s predecessor, Frank Law, remembers the birds in their abundance, even back to a time when they were driven and shot on formal capercaillie days. “We’d aim for a bag of 10 or 20 birds in a day,” he says. “They were common back then. You’d expect to see a few of them every time you went into the forest, usually in the morning when they came out to find grit on the forest tracks.”
Seafield and Strathspey Estates stopped shooting capercaillie when declines were identified, but the birds have continued to decline ever since, even after they were given full legal protection in 2001.
Capercaillie are closely associated with Caledonian pine forests, and individual birds will use a mosaic of habitats including moorland, bog forest, and stands of mature conifers depending on the season. At a national level, these habitats have been badly fragmented and degraded during the 20th Century, and it’s not hard to see why the birds have steadily declined in the face of major changes.
Kinveachy carries a number of prestigious designations for its woodland habitats. Parts of the estate are recognised as a Site of Special Scientific Interest and, given that almost 20 percent of Scotland’s birds are found there, it’s also listed as a Special Protection Area for the birds. The forests on the estate are in excellent condition and getting better.
Habitat Management: A Promising Approach but Not Enough
A vast amount of work has gone into regenerating extensive areas of ancient woodland, which was felled as part of the war effort, and Kinveachy is meeting its woodland creation goals through deer management and careful monitoring.
Deer are culled to allow natural regeneration, but the year-round presence of herbivores at low densities means that brood-rearing habitats are kept open in a condition that is well suited to young capercaillie. Although it represents a great deal of hard work, this approach is more productive than the use of fences to exclude deer altogether.
Striking a balance with deer is not easy, but there’s every sign that Ewan’s team is getting things right. Kinveachy covers a large area, but capercaillie naturally move across even larger spaces during the course of a year.
There is a sense that some neighbouring land managers are pulling in different directions when it comes to deer management and capercaillie conservation, and it’s possible that Kinveachy is surrounded by less productive habitats where predator control is not treated as a high priority. This is an important issue to consider, even where collaboration and partnership working is generally good.
However, beyond discussions around habitat creation and management, it’s also clear that the birds themselves are not responding. Without tackling other root causes of capercaillie decline, Ewan’s fear is that at Kinveachy, “we’re going to have a pristine woodland that is expanding in size and character but without its full potential biodiversity.”
The estate is a clear example where good habitat management alone is proving insufficient for capercaillie. GWCT Research Assistant Kathy Fletcher is confident that poor productivity is driving declines, and this means that female birds are unable to produce enough youngsters each year to replace natural losses.
There is some evidence to suggest that the problem is exacerbated by poor weather and recreational disturbance, but predation is a major concern. Kathy’s work has contributed to a wider understanding of how crucial predator control can be for capercaillie. As she explains: “We know that when predators like crows and pine martens are in high abundance, capercaillie are found at lower densities, and this is borne out and confirmed by a recent report for the capercaillie Scientific Advisory Committee (SAC), which was commissioned by NatureScot in 2021.”
Predator Control: The Pine Marten Predicament
The SAC report is very clear about the current drivers of decline, and it confirms what many gamekeepers and researchers have been saying for years. Habitat is not the limiting factor for capercaillie in Scotland, and acknowledging the hard work of estates like Kinveachy, it’s clear that more good habitat becomes available every year. In the words of the report: “Predation is a significant contributor to variation in breeding success. Increases in some nest predators (notably the pine marten) in recent years are likely to be contributing to the decline in capercaillie breeding success and hence population size.”
A proactive engagement with predator control at Kinveachy means that foxes and carrion crow numbers are kept at a very low level, but pine martens are fully protected by law. There is currently no legal mechanism that allows them to be managed, and here is the root of the issue The pine marten is a native species to Scotland, although historical persecution meant that their impact was confined to a handful of marginal sites until relatively recently.
As part of an extensive expansion across Scotland over recent years pine martens returned to Strathspey during the 1970s. Their numbers have grown substantially ever since, and they have quickly become a common species in the area. Hard data are difficult to come by because capercaillie have become so scarce, but there is enough evidence to suggest that pine martens have become a very significant predator of capercaillie. Both are protected by the same level of legislation, but it’s clear that one protected species could soon drive another into extinction.
The Urgency of Taking Action: Saving the Capercaillie
For Frank Law and Ewan Archer, predator control is clearly a crucially important tool for conserving capercaillie, but the work is only of limited value if pine marten numbers remain unmanaged. While some conservation organisations have tried to find a way around the issue, a range of land managers insist that the only practical way to save capercaillie is to introduce a legal mechanism to permit the lethal control of pine martens.
As Frank Law explains: “It might be possible to trial a range of new conservation measures in the future, but now is not the time. We might only have four or five hundred of these birds left in Scotland. If we had four or five thousand, maybe there would be an opportunity to take our foot off the gas and see what else we can do. The goal now is simply to keep them in Scotland, full stop. We can still turn this situation around. It would be an act of folly to miss this opportunity.”
Many of the non-lethal techniques put forward as alternatives, are impractical. Trapping and relocating martens is extremely complex and expensive. Attempts to provide diversionary feeding for martens are only in the earliest stages and results are unclear. GWCT’s Scotland director Rory Kennedy believes a way through could lie in contraceptive baits, a technique currently being trialled with grey squirrels.
He said: “The problem with issuing special licences for controlling pine marten is that to be effective, it would need to take place on a landscape scale. Many estates surrounding Seafield and Strathspey will not countenance lethal control on ideological grounds. In addition, the current inability to address pine marten predation is used as a reason for many landowners to avoid the clear recommendations of the SAC, regarding the need for crow and fox control across the entire capercaillie range. We need to address this, if we are to save this species. Diversionary feeding combined with contraceptive population control could provide a workable outcome palatable to all parties.”
There are many factors to consider for the future. In parts of Scandinavia and Russia, pine martens and capercaillie are able to find a more natural balance, which does not depend upon human intervention. It’s clear that capercaillie numbers are now so low in Scotland that normal rules do not apply, and while it’s important to plan for a more natural future where predator and prey can find a lasting balance, the first challenge is to protect what we have to ensure these birds have a future at all. If we fail in this and lose the capercaillie from Scotland, there’s a risk that our pristine and resurgent Caledonian pine forests will always feel a little empty.