Which bird has tips at the end of its beak enabling it to probe deep into soft mud for its food? How many tonnes of gravel are needed to make each mile of new motorway? Not all teachers may know the answers to these questions but a group of pupils from Year 5 at Stanton Middle School in Buckinghamshire certainly do. They have just spent a day at the ARC Environmental Study Centre in Milton Keynes at the heart of a site that was once a huge gravel pit and is now transformed into a nature reserve.

Their morning started with a slide show explaining how the reserve was developed. The site used to provide the sand and gravel that went into the making of both the New Town of Milton Keynes and the Ml. Then the owners, the aggregate Company ARC, alongside the Game Conservancy, turned it into a sanctuary for research into wildlife and plant conservation.

The slides showed massive bulldozers and pumps at work, creating artificial lakes and ponds. To attract wildlife, topsoil and gravel were used to create islands with banks deliberately sloped so that birds, frogs or newts could hop in and out of the water. To prevent erosion of the shores, telegraph poles were laid down and reeds planted.

Fifteen years on, the reserve has attracted an abundance of wildlife. A collection of hands-on mounted specimens help with identifying birds. This was used by the education officer, Ian Duckworth, to give a fascinating introduction into the way different species, according to the design of their feet, bodies or beaks, are equipped to dive for fish or pick up worms and insects from the fields.

Coats and wellies donned, we went out to see the reserve for ourselves. Each member of the group was equipped with binoculars, a map and photographs of the site as it was in 1980 and 1985 and as it is now. The first exercise involved map-reading, then making detailed observations of the way the landscape had changed in the 10 years since the children were born! The highlight of the day followed - a visit to a hide to see birds on the lake. What species can you see, what colours are they, what are they doing, what have they in their beaks? With binoculars focused, the answers came thick and fast. Swans, wigeon, cormorants on a raft, teal drifting by. Then a pair of coots, powerful backs arching out of the water as they fought, possibly over a female. One boy correctly spotted the colour of a mallard’s eye - yellow.

The afternoon was spent on a different aspect of human impact on the environment. Another slide viewing showed the sand and gravel being excavated, processed and put to use in multifarious different ways from road works to filling goldfish bowls. This was followed by a joyful period in the lab, emulating the sorting processes. The children sieved piles of gravel into four different sizes from less than 2 to more than 14 mm, then completed work sheets on the functions of each size of aggregate.

Year 5 teacher Claire Moss, who is following KS2 topics on conservation, habitat and human impact on the environment, had only praise for the Centre. She particularly values “the expertise of the leaders, the stimulus they give the children and the motivation the pupils get from first-hand experience in the environment”. In truth it was not necessary to ask if the children had benefited. That was obvious from their questions and discussion, the amazing amount of information they had remembered from a previous visit, and from the enthusiasm they bestowed on their tasks.

Only recently launched, the Study Centre is the result of an enlightened partnership between ARC and and Buckinghamshire County Council, one of the few counties with a separate environmental education service.

A wide-ranging set of projects and accompanying worksheets are available for the age-range 8-13: other groups are welcome to approach the Centre who try to meet individual needs.

o Arc Environmental Study Centre: free to Buckinghamshire schools, tel: Ian Duckworth on 01296 668820. Other schools call the warden on 01908 604810.