Twice as Many Curlews on Managed Blanket Bog, Teesdale Survey Finds

✅ Key Takeaway: Blanket bog managed by burning or cutting held about twice the curlew density of unmanaged bog in Teesdale.

A new survey of Upper Teesdale recorded about twice as many curlews on blanket bog managed by burning or cutting as on bog left unmanaged. Managed bog held roughly four breeding pairs per square kilometre against under two on unmanaged bog.

It also carried a disproportionate share of the dale's curlews: 23% of the birds on 21% of the land, while unmanaged bog held only 8% of the birds across 18% of the area.

Across the dale as a whole, curlews were densest not on bog at all but on rough grazing and grass moor at middle elevations. Blanket bog of either kind sat lower down the ranking, which makes the gap between managed and unmanaged bog the more striking: even among the dale's less favoured ground, active management roughly doubled the birds.

That gap carries extra weight because of the population it comes from. Upper Teesdale holds 1,764 breeding pairs of curlew, close to 3% of the entire UK total, and counts repeated about a decade apart showed the population essentially flat, a 3% change statistically indistinguishable from none.

While the national curlew population fell by roughly half between 1995 and 2021, this dale held its ground.

Why management might lift curlew numbers

Curlews do better where moorland vegetation is structurally varied rather than uniform, with a mix of heights and open patches for nesting and feeding (Pearce-Higgins and Grant 2006).

Burning and cutting break up an even sward and create that variety. Earlier research in the North Pennines found the same management associated with rising numbers of curlews and golden plovers (Douglas et al. 2017).

On these moors, burning and cutting are part of managing the land for red grouse, but their effects reach well beyond a single species.

By promoting the protein-rich cottongrass flowers and fresh heather shoots that grouse feed on, the same work breaks up an even sward and builds the varied structure that nesting curlews depend on.

The high wader numbers are less an incidental side effect than a sign that management shaped around grouse also sustains the wider moorland bird community.

What it means for policy

Burning on blanket bog has been restricted in England since 2021, with cutting offered as the replacement (DEFRA 2021). The Teesdale authors warn that if cutting fails to reproduce the vegetation structure that burning created, moorland waders could decline further.

The caution is conditional, but it rests on evidence: managed bog in this study, whether burned or cut, held twice the curlews of bog left alone.

Vegetation management is not the only thing setting Teesdale apart. Gamekeepers removed foxes and crows across most of the dale year-round, and the curlews here fledged 1.0 chicks per pair, twice the rate needed to sustain numbers.

The high densities on managed bog sit inside that wider keepered, extensively farmed landscape, so the bog result is one strand of a larger management picture rather than a single lever.

The practical reading

For anyone working upland bog, the survey offers a clear but bounded message. Curlews were far more abundant where the bog was actively managed than where it was left alone, and that pattern held within a population large and stable enough to matter nationally.

The study cannot prove burning by itself delivered the difference, and it cannot weigh burning against cutting. What it does is put hard numbers behind a plain proposition: blanket bog managed for grouse carried more than double the density of a globally near-threatened wader, and restricting those management tools without a tested replacement bets against that evidence.