THE biggest single predator threatening ground-nesting birds in Upper Teesdale is the stoat.

A study of the curlew population over two seasons found hardly a chick was bred because of stoats.

Lindsay Waddell, head gamekeeper for the Raby Estates in Upper Teesdale, said a male stoat in spring would cover up to 5,000 acres looking for a mate. "It is a massive range for a creature only eight or nine inches long," he said, "They live like nomads, and that is the problem."

Each year 500-600 stoats are killed on the 30,000-acre estate but they still wreak havoc among the many ground-nesting birds, including grouse and waders.

Mr Waddell was addressing a meeting of the Nidderdale Area of Oustanding Natural Beauty project at Pately Bridge on Tuesday of last week.

Mink and weasels were also predators, plus an occasional fox, but the other major problem was the herring gull. These could spot eggs in an open nest from 30 metres away and would swoop at the slightest opportunity.

It was one of the points to be considered when discussing access to the moors. Any sitting birds disturbed by unsuspecting walkers would fly off, leaving the eggs a sitting target for gulls and other predators.

Mr Waddell was speaking about managing a grouse moor.

The average grouse nest would contain eight to ten eggs in a good year but it took only a couple of eggs either side of that to make a huge difference. The chicks grew from start to finish in just 12 weeks because of the tough terrain and climate.

People travelled from all over the world to shoot the red grouse and provided vital income for the area. The estate's average wage bill in the shooting season was £20,000, which went into the pockets of local people. The actual grouse shot could be in London, or even France, the next day.

Mr Waddell said the curlew was the gamekeeper's best friend because of its alarm call. "Many a stoat and fox has died because of it," he said.

In Teesdale the lapwing was doing well and and there were populations of golden plover, redshank and a high density of snipe. The oyster catcher was doing well, with about 100 pairs, and the grey partridge, in real trouble in England, was doing reasonably well in Teesdale.

Mr Waddell spoke about general management of the heather moorland on the estate.

Intensive draining had taken place on the moor immediately after the Second World War to encourage food production. The drains were originally 18in wide by 18in deep, but had been eroded to the point where some were big enough to hide a single decker bus.

Thousands of tonnes of peat and silt had been washed downstream over the years but, some years ago, the estate began a programme of blocking the drains. "Thousands of gallons of water is now held back on the moors through the ponds that have been created," said Mr Waddell.

Fewer sheep and lambs were dying through getting trapped in the drains as natural bridges were created by the blocking process.

A concerted bracken eradication programme began 15 years ago, using helicopters to spray areas. "We were not as bad as the North York Moors for bracken and have been fairly successful in removing it but it has taken about 15 years," said Mr Waddell.

He explained the management of heather, from burning to re-seeding. The seed could remain viable for 100 years, given the right conditions, but did need light to germinate.

The entire moor was a Site of Special Scientific Interest and national nature reserve and scientists and botanists from as far as Japan and America went to see the Teesdale pansy. There were also many rare alpine plants and flowers, which had all been helped through sheep management and the introduction of Galloway cattle for grazing certain areas.

Returning to predator control, Mr Waddell showed some of the traps used - all legal. On average they found about 50 a year, worth £5 apiece, which had been damaged by people who did not approve, and others which cost £75 to £100 to replace.

"The thing is that people who do this are actually breaking the law while we are abiding by the law in using them," said Mr Waddell.

In his years on the estate he had witnessed only one moorland fire, caused by a chain smoker among four egg thieves, who were apprehended. "The fire covered a quarter of an acre but it took 6,000 gallons of water to put out, we had two fire tenders in attendance," he said.

He showed a slide of the scene left by trespassers who dumped dozens of empty beer cans and evidence of drugs during an overnight stay. They had used an axe to chop down expensive fence posts and a wooden gate for a fire.

Mr Waddell said that, in one year, 100 night-time poachers were caught in Teesdale - most had previous convictions.