THE sight of sheep roaming across the North York Moors could soon be a thing of the past, according to research.

And conservationists are warning that the lack of grazing animals could change the landscape forever with open moorland giving way to scrub and woods.

Figures from the North York Moors National Park Authority show more than three flocks a year are being taken off the moors. Most are then sold.

If that rate of decline continues, there will be no sheep left by 2033.

The authority has teamed up with English Nature and Askham Bryan College, near York, to try to find out how to halt the decline.

The college will look at the running of six upland farms and how much they are likely to earn over the next five years.

Rachel Pickering, moorland project officer with the authority, said: "The study aims to find out the actual cost of keeping sheep on the moor. Everybody knows that it is uneconomic, but nobody actually has a figure to put on it."

Hill farmers say it is becoming increasingly difficult to gather in sheep. With fewer flocks on the moors, they are spreading further afield.

Gordon Featherstone has more than 1,000 sheep at Moor House in Bransdale, near Kirkbymoorside.

He has kept his flock on the moor while many of his neighbours have taken theirs off.

"It is more difficult because you don't have the neighbours helping anymore when you are gathering them in," he said.

Hill farming in the Yorkshire Dales is also under threat. Last July, the National Trust warned that hill farming in areas such as the Dales was on the brink of collapse because of reforms to the Common Agricultural Policy.