Berwyn's Birds: The Impact After Driven Grouse Shooting Ended
- Rob Beeson
- Apr 4
- 6 min read
High up in the rugged beauty of North Wales lies the Berwyn Special Protection Area (SPA), a sprawling expanse of blanket bog and upland heath. This area is a crucial haven for a diverse array of bird species, some of which are of international significance.
The Berwyn is constantly changing. A detailed study, spanning several decades, looked at these changes, revealing fascinating trends and raising important questions about the future of this precious ecosystem.
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More Than Just a Pretty Landscape
The Berwyn SPA, stretching across 241.8 square kilometers, is a vital area for conservation in Wales. Designated in 1998, its primary role is to protect significant populations of birds like the hen harrier, merlin, peregrine, and red kite. Beyond these flagship species, the Berwyn also supports substantial proportions of Welsh populations of upland breeding waders and is recognized as a Site of Special Scientific Interest (SSSI).
The landscape itself is a mosaic of habitats, transitioning from upland fringes at lower elevations to acid grassland, dry heath, and ultimately, the extensive blanket bog at higher altitudes. This blanket bog, dominated by heather and cotton grass, is the most extensive in Wales. The area also boasts the largest stand of upland European dry heath, characterized by heather and bilberry. This rich variety of habitats provides crucial breeding and feeding grounds for a wide range of bird species.
Bird Population Shifts
To understand how bird populations in the Berwyn have changed over time, researchers from the Game & Wildlife Conservation Trust (GWCT) conducted a comprehensive analysis. Their study looked at several key data sources, covering different periods:
Upland Bird Surveys (1983-85 & 2002): These repeat surveys across 107 one-kilometer grid squares provided a snapshot of the abundance and distribution of a wide range of upland birds.
Red Grouse Surveys (1995-2012): Regular counts of red grouse on four specific moors (Vyrnwy, Ruabon, Pale, and Llanarmon) offered detailed insights into their population trends.
Shooting Bag Records (1880-2010): Historical records of red grouse shot on four moors provided a long-term perspective on their abundance, particularly in relation to grouse moor management.
By combining these different datasets, the researchers were able to build a detailed picture of the changes that have occurred in the Berwyn's bird community over the past few decades.
Red Grouse: From Boom to Low Levels
The historical shooting bag records paint a clear picture of a once thriving red grouse population in the Berwyn. Numbers peaked in the early 1900s, with one moor recording an astonishing 282 grouse shot per square kilometer. While there was a post-World War II increase, numbers generally declined, and by the early 1990s, grouse were infrequently shot.
A significant shift occurred with the cessation of driven grouse moor management in the Berwyn by the late 1990s. This type of management involves activities like heather burning and predator control to create favourable conditions for red grouse. Today, only less intensive walked-up grouse shooting is practiced in some areas.
The more recent grouse count data from 1995 to 2012 on four moors reveal that red grouse numbers have remained at low levels on three of them. Notably, at Llanarmon, summer densities of adult grouse declined significantly from 15 grouse per square kilometer in 1995 to just 3 in 2009.
Compared to other areas in the UK where grouse moor management continues, the Berwyn's red grouse densities are now considerably lower. In fact, red grouse in Wales are now considered critically endangered following a rapid decline in their range and abundance.
The Decline of Breeding Waders
Perhaps one of the most concerning findings of the study is the dramatic decline in upland breeding waders between the 1983-85 and 2002 surveys.
Lapwing, once present in low numbers, had completely disappeared from the surveyed areas by 2002.
Golden plover numbers plummeted by 90%.
Curlew experienced a staggering 79% decline, despite their conservation designations. Their occupied range also shrank by a massive 75%.
Snipe numbers also showed a decrease, although less drastic.
Overall, the abundance of all breeding waders combined declined by 80% during this period. This significant loss is a major cause for concern, highlighting the vulnerability of these iconic upland birds in the Berwyn.
Winners and Losers in a Changing Landscape
While the waders faced a steep decline, the passerine bird community showed a more mixed picture.
Significant Increases:
Meadow pipits and whinchat doubled in number.
Stonechat experienced a remarkable ten-fold increase.
Other passerines like wren, willow warbler, whitethroat, grasshopper warbler, and chiffchaff also showed notable increases. Even woodpigeons increased significantly.
Significant Decreases:
Ring ouzel numbers declined by a concerning 78%.
Tree pipit also saw a substantial 50% decrease.
These changes suggest a shift in the suitability of the Berwyn habitat for different passerine species. The increase in scrub-associated species like willow warblers and wrens, alongside declines in more open moorland specialists like ring ouzels, hints at potential vegetation changes.
The Rise of Corvids and Raptors: A Cascade Effect?
The study also documented significant changes in the populations of corvids (like crows and ravens) and raptors (birds of prey).
Carrion crow numbers increased six-fold, with their occupied range doubling.
Raven populations quadrupled, and their occupied range tripled.
Buzzard abundance doubled, and their occupied grid squares increased four-fold.
Peregrine numbers increased seven-fold.
However, not all raptors fared well. Hen harrier numbers declined by half during the study period. While longer-term monitoring suggests some recovery in hen harrier numbers more recently, the Berwyn SPA has still struggled to meet its target breeding pair numbers for hen harriers, as well as for merlin, peregrine, and red kite, indicating an unfavourable condition for these designated species.
Understanding the Driving Forces Behind These Changes
The cessation of driven grouse moor management appears to be a key factor influencing the observed changes. The absence of regular heather burning and predator control, which were integral to grouse moor management, has likely had cascading effects on the wider bird community.
Impact on Waders: Grouse moors managed for red grouse have been shown to support higher densities of breeding waders compared to unmanaged moorland. The decline of waders in the Berwyn after the cessation of management aligns with this observation. The lack of predator control is a likely contributing factor, as generalist predators like carrion crows and foxes have likely increased in the absence of active management.
Habitat Shifts: Changes in grazing patterns and the absence of heather burning have likely led to subtle changes in vegetation structure, potentially making the habitat less attractive to some species (like waders) and more favourable to others (like scrub-loving passerines). The maturation of commercial forests in the area has also reduced open moorland habitat and potentially provided cover for predators.
Raptor Dynamics: The increase in buzzards and peregrines reflects broader UK trends, likely linked to recovery from past persecution and pesticide use. However, ground-nesting raptors like hen harriers and merlins can be vulnerable to increased predation in the absence of predator control.
Looking Ahead: Conservation Challenges and Recommendations
The findings of this study underscore the dynamic nature of upland ecosystems and the complex interplay of factors influencing bird populations. The significant declines in breeding waders are a major conservation concern, raising fears that species like lapwing, golden plover, and curlew could be lost from the Welsh uplands in the coming decades without intervention. These birds exhibit strong site fidelity, meaning if they disappear from a breeding area, recolonization is unlikely, even if conditions improve.
To address these challenges and restore breeding wader populations in the Berwyn SPA, the report recommends:
Incorporating predator control as a general tool within agri-environment schemes, particularly in areas where habitat enhancements through heather burning and appropriate grazing are being implemented. Predator control, targeting generalist predators like carrion crows and foxes, has shown positive results for wader breeding success in other regions.
Implementing habitat management through heather burning and appropriate grazing to create more suitable conditions for moorland birds.
The report notes that restoring traditional grouse moor management in its entirety in the Berwyn would be difficult and expensive due to factors like habitat fragmentation, disease, high raptor densities, and restrictions on heather burning on blanket bog. Therefore, a more integrated approach focusing on targeted predator control and habitat management within existing agri-environment schemes is likely the most viable path forward.