There are fears the birds and animals that feed on them may be knocked out of synchronisation.

The Lulworth skipper, which normally does not emerge until the 3rd week in June, was this year sighted on April 28 in Dorset - a record-breaking seven weeks early. The speckled wood was also seven weeks premature, usually emerging at the end of March, but this year was seen in Cornwall as early as January 16.

The wall brown, chalkhill blue and green hairstreak, have all been spotted six weeks earlier than usual. The Glanville fritillary, meanwhile, emerged five weeks before it would normally appear during the 3rd week of May.

Those appearing a month early include the large skipper, the small blue and the meadow brown.

But, said Dr Martin Warren, chief executive of Butterfly Conservation, the warmer spring months are doing little to combat the decline of butterflies, with 70 percent of our 59 resident and regular migrant species suffering from loss of habitat.

"It is quite extraordinary how many species are coming out early, some of them at their earliest ever sighting," he said. "I spotted the Lulworth skipper myself and took a photograph just in case no-one believed me."

"I think what it means is yet more confirmation that climate change is having a big impact on wildlife in Britain.

"Insects are a good indicator because they rely on temperature for their activity. And three-quarters of our species are insects. If butterflies are doing things much earlier then it shows that climate change is really having a big impact on the whole life cycle.

"It means that those eating the species also have to change. We don't know yet, but it is quite likely some things could get out of synchronisation - such as birds rearing their young. They might get out of sync with their hostss, and this is a phenomenon we are watching carefully.

"Overall butterflies are declining. Seven out of ten species are affected and the reasons they are declining is very worrying.

"We would expect most species to do better as the climate warms as they are already on the edge of their range. But they seem to be doing the opposite and that is because of the loss of their habitat.

"Butterfly rich meadows are just a thing of the past. When did you last walk through a really rich flowering meadow - a real meadow not Kew Gardens? I bet most people can't remember.

"The chalk grasslands have declined by 60 percent since the war because of development. The ancient broadleaf woodlands are also in decline.

"Early emergence is interesting. It shows just how rapidly things are changing out there. But we don't yet know if it will impact on their survival and we are very concerned about the loss of habitat.

"We are worried the new planning regulations coming in may lead to yet more habitat loss. It's a one way street. There is not a lot of restoration of habitat going on".

During a warmer than normal January, there were sightings of the red admiral, peacock. small tortoiseshell and the comma, though this is not unusual. They overwinter as adults, and not eggs or chrysalises, so very warm weather can just wake them up.

April was the hottest April since records began in 1659.

Dr Tom Brereton, Head of Monitoring with Butterfly Conservation, said: "Butterfly data, collected by hundreds of UK recorders, definitely points to climate change.

"Species are not only emerging early but several species are extending their geographic range northwards."

The small skipper, comma and holly blue have all crossed the border into Scotland in the last few years, very probably as a result of climate change, he said.