填空题 For 40 years the sight of thousands of youngsters striding across the open moorland has been as much an annual fixture as spring itself. But the 2,400 school pupils who join the grueling Dartmoor Ten Tors Challenge next Saturday may be among the last to take part in the May tradition. The trek faces growing criticism from environmentalists who fear that the presence of so many walkers on one weekend threatens the survival of some of Dartmoor's internationally rare bird species.
The Ten Tors Challenge takes place in the middle of the breeding season, when the slightest disturbance can jeopardize birds' chances of reproducing successfully. Experts at the RSPB and the Dartmoor National Park Authority fear that the walkers could frighten birds and even crush eggs. They are now calling for the event to be moved to the autumn, when the breeding season is over and chicks should be well established. Organisers of the event, which is led by about 400 Territorial Army volunteers, say moving it would be impractical for several reasons and would mean pupils could not train properly for the 55-mile trek. Dartmoor is home to 10 rare species of ground-nesting birds, including golden plovers, dunlins and lapwings. In some cases, species are either down to their last two pairs on the moor or are facing a nationwide decline.
Emma Parkin, South-west spokeswoman for the PASPB, took part in the challenge as a schoolgirl. She said the society had no objections to the event itself but simply wanted it moved to another time of year. "It is a wonderful activity for the children who take part but, having thousands of people walking past in one weekend when birds are breeding is hardly ideal," she said. "We would prefer it to take place after the breeding and nesting season is over. There is a risk of destruction and disturbance. If the walkers put a foot in the wrong place they can crush the eggs and if there is sufficient disturbance the birds might abandon the nest." Helen Booker, an RSPB upland conservation officer, said there was no research into the scale of the damage but there was little doubt the walk was detrimental. "If people are tramping past continually it can harm the chances of successful nesting. There is also the fear of direct trampling of eggs." A spokesman for the Dartmoor National Park Authority said the breeding season on the moor lasted from early March to mid-July, and the Ten Tors Challenge created the potential for disturbance for March, when participants start training.
To move the event to the autumn was difficult because children would be on holiday during the training period. There was a possibility that some schools in the Southwest move to a four-term year in 2004, "but until then any change was unlikely. The authority last surveyed bird life on Dartmoor two year ago and if the next survey showed any further decline, it would increase pressure to move the Challenge," he said.
Major Mike Pether, secretary of the army committee that organises the Challenge, said the event could be moved if there was the popular will. "The Ten Tors has been running for 42 years and it has always been at this time of the year. It is almost in tablets of stone but that's not to say we won't consider moving if there is a consensus in favour. However, although the RSPB would like it moved, 75 per cent of the people who take part want it to stay as it is," he said. Major Pether said the trek could not be moved to earlier in the year because it would conflict with the lambing season, most of the children were on holiday in the summer, and the winter weather was too harsh.
Datmoor National Park occupies some 54 sq km of hills topped by granite outcrops known as "Tors" with the highest Tor-capped hill reaching 621m. The valleys and dips between the hills are often sites of bogs to snare the unwary hiker. The moor has long been used by the British Army as a training and firing range. The origin of the event stretches back to 1959 when three Army officers exercising on the moor thought it would provide a challenge for civilians as well as soldiers. In the first year 203 youngsters took up the challenges. Since then teams, depending on age and ability, face hikes of 35, 45 or 55 miles between 10 nominated Tors over two days. They are expected to carry everything they need to survive.

填空题 What is the Ten Tors Challenge? Give a brief introduction of its location and history.

填空题 Why is it suggested that the event be moved to the autumn or other seasons?

填空题 What are the difficulties if the event is moved to the autumn or other seasons?