Upland Predator Control Works - and the RSPB Just Proved the Principle

KEY TAKEAWAY: Targeted predator control - on islands and on moorland - is an evidence-backed conservation tool that measurably improves breeding success for vulnerable ground-nesting birds.

The RSPB has completed a programme to remove feral ferrets from Rathlin Island, Northern Ireland, to protect breeding puffins and guillemots from predation.

It is a clear, practical example of a principle that moorland gamekeepers apply every day: when vulnerable ground-nesting birds face unsustainable predation pressure, targeted removal of the predators responsible is one of the most effective conservation tools available.

The parallel between Rathlin Island and the English uplands is direct. Both involve removing abundant, generalist predators to give declining bird populations the conditions they need to breed successfully. The tool is the same. The evidence base is the same. The only difference is the landscape.

Ground-nesting birds in the uplands face the same threat

On Rathlin, the problem was ferrets predating seabird eggs and chicks. In the English uplands, the species under pressure are curlew, lapwing and golden plover - all ground-nesting birds whose eggs and young are highly exposed to foxes, stoats and carrion crows.

These predators are adaptable, widespread and present in high numbers. Without intervention, a single spring can see an entire cohort of wader chicks lost. For species already in long-term decline - the UK’s breeding curlew population has fallen by an estimated 48% since 1995, according to the British Trust for Ornithology - those losses compound quickly.

Upland predator control, carried out legally by trained gamekeepers, is the primary management tool used to reduce this pressure during the nesting season.

Peer-reviewed research confirms the effect on curlew breeding success

The case for upland predator control does not rest on tradition alone. Peer-reviewed field studies - conducted over multiple years and across different sites - consistently show large, measurable improvements in breeding success where predators are managed.

Three findings stand out:

• The Game & Wildlife Conservation Trust (GWCT) recorded an average of 1.05 curlew chicks fledged per pair on keepered moorland, compared with 0.27 on unkeepered land - a fourfold difference and, for curlew, the gap between a population that can sustain itself and one that cannot.

• The Upland Predation Experiment, led by the GWCT in partnership with Natural England, found that legal predator control more than trebled breeding success for curlew, lapwing, golden plover and red grouse.

• Follow-up monitoring after the experiment ended showed that when gamekeepers left and predator control ceased, wader breeding success dropped back to pre-management levels within a short period.

These are not isolated results. They reflect a consistent pattern: active management during the breeding season produces measurably better outcomes for some of England’s most threatened bird species.

The Berwyn SPA shows what happens when management stops

The Berwyn Special Protection Area (SPA) in Wales provides a well-documented case study in the opposite direction. Following the withdrawal of predator control and traditional heather management, the area’s breeding wader populations collapsed.

According to survey data reported by the GWCT, lapwing became locally extinct at Berwyn, golden plover numbers fell by 90%, and curlew declined by 79%. The site was designated specifically to protect these species. The designation alone was not enough.

Berwyn is not an argument against protection - it is an argument for combining legal protection with the practical management tools needed to make it effective. Upland predator control is one of those tools.

A common principle, applied in different landscapes

The RSPB’s decision on Rathlin Island and the daily work of moorland gamekeepers rest on the same evidence-led logic: where predation is the primary constraint on a declining bird population, reducing that predation pressure improves breeding outcomes.

This is not a contested fringe position. It is mainstream conservation practice, supported by field data from island, coastal and upland habitats alike. The question is not whether targeted predator management works. The research is clear that it does. The question is whether we are prepared to use it consistently in the landscapes where it is most needed.

What you can do

If you want to understand the evidence behind moorland management in more detail, read the Moorland Association’s science and research pages. To support the work of the gamekeepers and land managers who carry out this conservation every day, consider becoming a member.