9th October 2023
The North Pennines support a nationally significant population of merlin and the long-term trend is stable, bucking the trend of decline in many other parts of the country.
Conservationists report an average of 35-40 nesting pairs across the moors of County Durham alone.
Our smallest bird of prey, the merlin is typically only 28cm in length and has an average weight of just 230g for the female, which is larger than the male.
One of those celebrating the good population of merlin is Emily Graham of the Northern Pennines Moorland Group, where nests are being monitored as part of ongoing survey work.
She said: “We are absolutely delighted to have ringed nine chicks from two nests this spring on one moor alone. It seems there are more merlin in this region than perhaps originally thought and it is wonderful to see them nesting successfully.
“Grouse moors offer the right balance of long and short heather to provide areas to nest in and take shelter, with fewer predators. We will always share data with other bodies to assist long-term monitoring and conservation work. We hope to encourage even more insects too, which will boost the number of small birds such as meadow pipits, skylarks and wheatears that form the major part of the merlin’s diet.”
David Raw, a British Trust for Ornithology licensed bird ringer and member of the Durham Upland Bird Study Group, has been monitoring merlin for over 30 years.
He says: “County Durham has one of the largest study populations of merlin of any region in the UK, with a population that has remained stable over the long-term. On this estate the team are very keen to do everything they can to help birds such as the merlin and the gamekeepers will report nest sites to us, to assist with long-term monitoring.
“Merlin nest among the heather of the moors in the uplands, with generally good breeding success in the spring, although possible poor winter survival rates deserve further study.”
After fledging on moorland, young merlin head to the lowlands and coastal plains, following their main prey – meadow pipits.
The birds are too small to carry the weight of a satellite tag, so conservationists and landowners are reliant on nest observation, or on members of the public alerting them when they find a ring, or a ringed dead bird.
David Raw continued: “From the recovered rings we collect data on the birds’ lifespan, movements and cause of death – sometimes they have accidentally flown into window panes or car windscreens and sometimes they appear to have died of starvation. Young merlin leave their parents’ care about 2-3 weeks after fledging so the inexperienced birds often do not find enough food to survive their first winter.”
Merlin are a red-listed species, meaning ‘of most conservation concern’ and there are estimated to be just 1,100 pairs in the UK. They are particularly vulnerable to predators as they nest on the ground, where their eggs and chicks may be eaten by stoats, foxes, crows and other species. Grouse moors provide a protected habitat for merlin as the number of ground predators is controlled.
The moor is designated as a Site of Special Scientific Interest for its rare birds of prey including short-eared owl and merlin and upland breeding birds including curlew, golden plover, ring ouzel and lapwing. The moor is also within the North Pennines’ Special Protection Area and Special Area of Conservation.
Previous research by Penny Anderson Associates published in 2014 found that almost 80% of 10km squares with breeding merlin in England were on grouse moors managed by gamekeepers.
Between 1988 and 2008 the percentage of breeding merlin records within grouse moors doubled from about 40% to 80%, but over the same 20-year period breeding merlin records outside grouse moors declined to 20%.