Farmland and moors around the national park are being examined as part of a survey which is focussing upon the birdlife of the region.
Curlew, golden plover, lapwing and snipe are the four species of wader that nest on the North York Moors.
While three of the birds are listed are ‘near threatened’, lapwing is ‘red’ listed - the highest conservation priority.
This means urgent action is needed to save the species, and the survey is being held to determine what can be done.
Simon Wightman, head of natural environment at the national park, said: “We were concerned about the decline in lapwing breeding, and curlew is becoming a worry with numbers in the UK declining by 45 per cent.”
Similar surveys of breeding waders were carried out in 1996, 2000 and 2008 and lead to large environmental impacts. The 1996 survey found golden plover to be breeding in internationally-significant numbers, which led to 44,000 hectares of moorland being designated as a Site of Special Scientific Interest and a Special Protection Area.
Mr Wightman added: “The picture is quite complex, but these surveys provide ‘snapshots’ of wader numbers which help us understand the overall picture.”