Giving black grouse a lift

Black grouse could be restored to the North York Moors this spring thanks to a GWCT translocation project that aims to expand the iconic bird’s range, writes Joe Dimbleby

Once present in every county in England, today black grouse are red-listed as a species of high conservation concern. The GWCT has been studying this iconic bird and monitoring numbers in the English uplands since the early 1990s. In that time the population has been broadly stable, fluctuating between 1,000 and 2,000 displaying males, but it remains restricted to the North Pennines: parts of County Durham, Northumberland, Cumbria and North Yorkshire. To build resilience into the existing population and mitigate against negative impacts of climate change, it is vital to expand their range.

A series of events, including rare sightings of greyhens in the North York Moors in recent years, widespread land manager support and landscape-scale habitat improvements, inspired the GWCT to apply to Natural England’s Species Recovery Programme to fund a project that could result in the first known black grouse breeding success in the North York Moors for decades. “The occasional appearance of a female was attributed to dispersal eastwards from the black grouse stronghold in the North Pennines but the birds were not settling, presumably due to an absence of males,” says Phil Warren, the GWCT scientist leading the project.

“Natural recolonisation of the North York Moors from the North Pennines is limited by the 30-kilometre gap of unsuitable lowland farmland habitat in the Vale of Mowbray. This is a particular issue for males, which normally don’t stray far from their breeding display areas known as leks,” he explains.

At higher altitude the North Pennines are generally cooler and wetter than the North York Moors. Such weather in June, when broods hatch, can lead to low chick survival. In comparison the North York Moors have much drier and warmer summers. These conditions, combined with significant landscape-scale management on the fringes of moorland managed for grouse shooting, have increased the amount of suitable habitat available for black grouse. “Bracken control, restoration of bilberry and heather moorland, returning conifer woodland plantations to bog, heath and scrub, and more extensive grazing on inbye grasslands are among the measures that have expanded the area of grousefriendly habitats,” says Warren. “All these factors led those of us at the GWCT to believe this is the right time to attempt an initial translocation of 20 black grouse from the North Pennines. But no ambitious project like this is possible without the support of the private landowners and gamekeepers who manage both the donor and recipient grouse moors and surrounding areas,” he adds. Black grouse remain on the quarry list but the sole intention of these working conservationists is to restore them as a breeding bird and build up the population. Jimmy Brough is headkeeper on Rosedale and Westerdale estate, one of the recipient sites. “There have been sporadic sightings of black grouse in the North York Moors in recent years but there is no record of them producing young. We would love to see them here, performing their magical mating display,” he says. (Read blackcock leks: a spectacular spectacle.)

Combination of habitats

More than 95% of England’s remaining black grouse live on the fringes of grouse moors where associated management provides them with the habitat they need. Nowhere is this more apparent than on Raby’s Upper Teesdale estate, which is home to 15% of the English population and is a donor site for the project. “Black grouse require a mix of heather moorland, rough grazed pasture, hay meadows and scrubby woodland on a landscape scale to allow natural movement between lekking groups. This combination of habitats also benefits a range of moorland fringe birds and so their presence indicates the health of the upland ecosystem,” explains Warren.

GWCT research indicates that forestry and closed-canopy woodland can have a negative impact on black grouse through the loss of moorland habitats. In contrast, sheep and cattle farming plays a pivotal role in delivering desirable sward for the insects on which the chicks depend in the first few weeks. In addition, fences are fitted with strike markers as a matter of course to prevent the birds colliding. At Raby small-scale tree and shrub planting in the gills with berry-producing species such as hawthorn or mountain ash provides winter food and cover. (Which types of grouse are toughest?)

Historically, large commercial conifer plantations have been avoided on parts of the estate. As ground-nesting birds, black grouse are highly vulnerable to predation. Accordingly, year-round legal predator control not just on the grouse moors but crucially on surrounding inbye land is carried out by the keepering team at Raby, led by Andrew Hyslop. “During the breeding season the estate endeavours to keep human disturbance to a minimum to avoid greyhens abandoning their chicks,” he says. “There is also a wild pheasant shoot in the dale and the black grouse benefit from the supplementary feeding sites that run from November to March.”

Raby’s land agent Joe Robinson has no hesitation in believing that going to such lengths is worth it. “Black grouse are a symbol of Raby; watching a lek is an extraordinary experience and a real privilege. But most of all they are an iconic North Pennines bird and a barometer of the conservation work of which we are extremely proud. That goes not just for the estate but our neighbours, tenants and partners, all of whom bolster our efforts,” he explains.

“However, conservation should not just be about preserving a species stronghold, it should be about expanding the range of this once-widespread bird and that’s where we think this project could make a real difference,” Robinson insists. “While game management absolutely underpins our efforts, it is not our only driver. We don’t allow the shooting of black grouse on the estate, as we’d rather any harvestable surplus be available for the preservation and expansion of this rare species.” In addition to the translocation, Warren and research assistant Holly Appleby are studying brood rearing and foraging habitats currently used by black grouse females in the North Pennines. “This phase began last spring when seven greyhens were caught and fitted with GPS tags under British Trust for Ornithology licence,” says Warren. “Tracking data identified the nest sites, start of incubation, hatch date, brood foraging and roosting locations, and was used by us to calculate the brood home range. Five of the females nested, three were predated but one re-nested and three chicks were hatched.” This study revealed that all the chicks that did survive were lost within a month of hatching, likely due to the lack of key insects in the critical early days. As part of the study, the GWCT team is looking at how livestock grazing influences the composition and abundance of invertebrates, especially sawfly larvae that are favoured by black grouse chicks. The findings will help guide landscape-scale management of moorland fringe grassland to increase chick food.

Positive signs

In November and December 2024 (with invaluable help from the Raby estate and other donor moors in the North Pennines) Warren, Appleby and GWCT director of research Andrew Hoodless began catching and moving black grouse to the North York Moors under licence by Natural England. It was a delicate operation. “In total 10 males and 10 females were successfully released just before the deadline of 10 December (the end of the black grouse season) after which date the licence prohibits them from being taken,” Warren explains. “Several of the birds were fitted with radio tags to study movements and survival rates. So far, I’m really pleased with the results.

“Subsequent visits to the North York Moors at the end of last year showed that all the birds have settled in the vicinity of the release area. This is a positive initial sign but there is still a long way to go and we will have to study the information gathered by radio-tracking closely before we can confirm a successful translocation,” he concedes. “The data will help us decide whether to make further releases, where they should be and whether we should try to establish a network of interconnected lekking groups.”

The GWCT has a long history of working with private land managers on the ground, which is critical to success. Raby’s Joe Robinson believes that building trust has been key to delivering so many of its conservation projects: “Phil and his team have a personal relationship with the land managers, which allows for rapid, constructive communication. The Trust’s scientific basis and extensive databases going back decades means its depth of knowledge is unrivalled.”

To date, the project has been funded by the Natural England Species Recovery Programme Capital Grant Scheme and supported by donations from the GWCT Black Grouse Appeal and BASC’s Wildlife Fund. In the long term, the survival and recovery of black grouse will depend on the continuation of the blend of public finance in the form of well-funded agri-environment schemes and private investment for which grouse management is a driver.

“We will continue to monitor the settlement patterns, survival, formation of leks by males in the spring and breeding productivity this summer to gauge the initial outcomes of the project,” says Warren. “Translocations of wild species are not always successful but we hope that this will help black grouse establish in the North York Moors and provide a blueprint to help recolonise other formerly occupied areas.”