The United Kingdom supports nearly 25% of the global Eurasian curlew (Numenius arquata) population, yet numbers have declined sharply—dropping by half in recent years. The primary driver behind this decline is low breeding success, not habitat limitations.
A large-scale study comparing grouse moors (with predator control) to unmanaged landscapes found significant differences in outcomes for curlew and other wading birds:
- 2x higher wader density on managed grouse moors
- 4x greater curlew productivity (1.05 vs. 0.27 fledglings per pair)
- 3–4x fewer predators such as foxes and corvids
Crucially, breeding success was strongly linked to predator presence, while habitat variables and grazing showed little impact. These findings were consistent across multiple wader species and validated through direct nest observations.
The research demonstrates that predator control plays a critical role in curlew conservation, with managed grouse moors functioning as source populations that help stabilize and rebuild declining numbers.
