WHEN asked to conjure up an image of the quintessential English summer, most people would think of blue skies, leafy glades, warm sunshine and ... butterflies.

The first three factors are not as reliable as they once were.

Sadly, neither are the butterflies.

These symbols of summer are declining fast as a result of human activity.

In the past 200 years, half the species in Britain have suffered decline; five have become extinct and 15 have been lost from more than half their range.

The only way back from this brink is if farmers, foresters and landowners are helped in managing their land in a more wildlife-friendly way.

One man who knows more than most about all this is Mr Peter Waterton of Great Ayton.

He is the butterfly recorder for North Yorkshire and helped compile a new book charting the fortunes of butterflies - The Millennium Atlas of Butterflies in Britain and Ireland.

Always interested in natural history, he started out having a moth-trap in the garden and went on to do a summer course on the identification of moths and butterflies. This was about 20 years ago.

"Doing this concentrated my interest towards butterflies and moths and I went to a meeting of the Yorkshire Naturalist Union and the Butterfly Conservation Society and volunteered for the job of local recorder," he said.

"This was three or four years ago when they were looking for people to co-ordinate information for the millennium atlas. I volunteered to collect all the data for vice-county 62 - North Yorkshire."

His task involved getting together records from across the county from various societies, trusts and contacts and sending out special forms for people to fill in quoting the dates of sightings and species.

"This covered the whole county and it was a vast project," said Mr Waterton.

And it was not all bad news.

His work showed that quite a few species had increased in their ranges locally, such as brimstone, comma, hedgebrown and speckled wood. They had all spread north over the past decade.

Dr Martin Warren, director of conservation for Butterfly Conservation, said: "Land use changes over the past 50 years have been disastrous for butterflies as their habitats have been lost to intensive agriculture and forestry."

But 15 species have expanded their ranges, almost certainly as a result of global warming. The Essex skipper and brown argus have doubled their ranges since the 70s and others, such as marbled white, are heading northwards rapidly.

But only butterflies able to use widespread habitats such as hedgerows and road verges have capitalised on our warmer climate.

Rarer species can no longer move between the small habitat fragments which remain in the countryside.

Mr Waterton said when he first moved to Great Ayton from Hertfordshire in 1983, the comma was unknown in this area.

Now it is right up in Northumberland and moving northwards quite rapidly.

But he warned: "A national survey was last done in 1957 and numbers have certainly declined since then. Those which need more specialised habitats have declined more than others.

"It is just a spin-off from modern life in that there has been a loss of various habitats around us.

"Butterflies are lovely to have around and they do some pollenating and provide food for other creatures."

He said species which did not need special habitats could adapt and so survive.

Those needing particular types of food were the ones really under threat and Mr Waterton said all we could do was ensure we did not lose any more of their particular habitats.

There are some 59 different species of butterfly in the country, and 37 have been recorded in Yorkshire, of which 33 breed.

Still the local recorder, even though the atlas is published, he is still compiling data and looking for new sites for species all over the county.

Work also goes on to monitor the situation and this takes up many hours - all voluntary.

Mr Waterton originally moved from Manchester to Hertfordshire then came to Great Ayton through his job as a senior research scientist with ICI.

Now retired, he said butterflies inspire him in his paintings - a hobby he has been able to indulge more since giving up work. The Bark Endeavour coming into Whitby is just one of his works.

To help the struggling butterflies, Mr Waterton said people could do more planting in their gardens with nice blooms for nectar, leaving a few wild spaces with nettles for caterpillars.

He said the North Yorkshire area had some scarce species of butterfly such as Duke of Burgundy, fritillary and Helmsley.

Indeed, purple hairskeats is in the Great Ayton area and has not been seen here before.

Mr Waterton spotted one by Captain Cook's monument and reckons the species is heading north.

He is also looking for moorland sites for the large heath, which likes mosses.

"If people went out exploring they could find things which are not known and help us with the mapping on rare species," he said. "They can contact me for forms and details and this would help draw a picture of what is around and what is going on."

Writing in the foreword to the atlas, Sir David Attenborough says: "Like miners' canaries, butterflies can give warnings of environmental dangers.

"Their plight mirrors the decline of farmland birds and sends a clear warning signal about the devastating effect we are having on our environment."

Butterflies of woodland and wet meadows have been the worst hit in recent decades.

To compile the atlas, 10,000 people contributed more than 1.6 butterfly sightings between 1995 and 1999, making it the biggest and most detailed survey ever.

The survey's organiser Mr Richard Fox praised the volunteers.

"This book shows that the public can make a substantial contribution to scientific knowledge simply by recording the butterflies they see," he said. "The records are a vital tool in the fight to conserve our butterflies."

Mr Paul Harding, head of the Biological Records Centre, said: "Our wildlife is undergoing continuous changes and butterflies are particularly sensitive indicators.

"The new book shows the importance of keeping an accurate record of our wildlife and the need to update this information regularly."

l Anyone interested in helping Mr Waterton locally can contact him on 01642 724270