Grouse moor management helps keep Teesdale curlews stable, study finds

Upper Teesdale’s curlews are holding their numbers while the species declines across Britain, and grouse moor management is one of the main reasons, a new study has found. Research by the Game & Wildlife Conservation Trust (GWCT), published in the journal Bird Study, estimates the North Pennines dale supports about 1,764 breeding pairs, roughly 3% of the UK population, with breeding success almost double the level needed to keep numbers stable.

What did the researchers find on the moors?

David Baines and Nicholas Aebischer surveyed breeding curlews across 114 one-kilometre squares within a wider upland landscape of 488 squares, and monitored 137 wader nests with camera traps. Curlews were present in 99% of surveyed squares and produced about 1.0 fledglings per pair, against the 0.5 to 0.6 thought necessary to hold a population steady. Repeat surveys about a decade apart found only a 3% change, not statistically significant, while nationally curlew numbers fell 49% between 1995 and 2021.

Blanket bog managed by burning or cutting for red grouse held twice as many curlews as unmanaged bog, which the authors say points to grouse moor vegetation management creating better structure and foraging for the birds.

What role did the keepers’ predator control play?

Across the seven estates in the study, 22 full-time gamekeepers carried out legal predator control at landscape scale. The cameras told the story: the most frequent clutch predators recorded were badgers, stoats and sheep, with only one fox recorded and no corvids at all, which the trust says reflects the effectiveness of culling across most of the study area. Of 50 nests camera-monitored in 2022 and 2023, 70% hatched, and 78% of all monitored wader nests hatched, with 19% lost to predation.

The findings sit alongside earlier work showing curlew productivity roughly four times higher on grouse moors than on comparable ground without predator control, and a Northumberland experiment in which year-round predator control trebled breeding success for curlews, lapwings and golden plovers.

What happens next?

The authors conclude that curlew conservation is most likely to succeed across large, connected landscapes where habitat management, predator control and wildlife-friendly farming work together, as they do in Upper Teesdale. The paper, High and stable Curlew numbers on low-intensity farmland and moorland managed for Red Grouse recreational shooting in northern England, is published in Bird Study, and the GWCT has issued a plain English summary for readers who want the detail.