The behaviour of Britain's wildlife is raising alarm about the seriousness of climate change as animals' breeding patterns are thrown into confusion. The second mildest winter on record has resulted in mammals, reptiles, birds and insects emerging from shelter far too early. They are getting caught out by cold snaps or wet weather and the young of many species are dying. Baby hedgehogs, baby squirrels, even baby grass snakes are being found in distress in many places.

The disturbing trend is emerging as climate change once again moves to the political centre stage. The Government's long-awaited Climate Change Bill will be published next week, the Environment minister Lord Rooker announced yesterday. Delays in the preparation of the Bill have led to questions being asked about the Government's commitment to tackling global warming.

Opposition parties fear that the Government's proposals will not be specific enough, and have pressed for annual targets in carbon dioxide reductions. The Environment Secretary, David Miliband, will go on the offensive over climate change next week. He will issue an undertaking to cut the UK's carbon output by between 15 and 25 million tonnes by 2020, although he will stop short of endorsing legally binding annual targets.

The visible impact on Britain's wildlife has manifested itself in the form of earlier than normal breeding, egg-laying, nesting and flowering of plants and trees, observed in British wildlife for more than 15 years and now linked to global warming in a whole series of scientific studies. They have sparked huge new interest in the discipline of phenology ­ the timing of natural events.

But until now the changes have been seen as potentially harmful in the future, rather than the present. That situation seems to have changed this winter. One place with a remarkable overview is St Tiggywinkles wildlife hospital near Aylesbury in Buckinghamshire, which has been admitting large numbers of rabbits, grass snakes and other young animals suffering from the new ailment of being born at the wrong time.

A typical inhabitant is Bushy, as he has been named by staff, a 10-day-old grey squirrel, still blind and about four inches long. He is being bottle fed and even needs human help to make his bladder work, a job normally done by his mother, from whom he was separated when their nest was disturbed by tree cutters.

"He really should not be here. He was born two or three weeks before he should have been," says Les Stocker, the founder of Tiggywinkles. "This is the busiest year we have had for these kind of animals being brought in," he added. "The animals are becoming active and mating earlier than normal, but you can still get sudden cold snaps to which they are vulnerable."

Cold weather can either kill young animals or prompt them into hibernation, from which they do not awake because they lack sufficient fat reserves. Toads and newts that should still be under a rock and pipistrelle bats which are normally still hibernating in hollow trees and barns have all been found out and about­ and there aren't enough insects around for them to survive on. The most unusual animals at the hospital are several edible dormice, so called because the Romans used to eat them. Not a native of this country, they are abundant in and around Tring in the Chilterns, where they have been breeding since escaping from a park 100 years ago. Ten times the size of a normal dormouse and looking more like a small squirrel, with a bushy tail, they normally don't emerge from hibernation until May.

Some baby birds have been brought into the hospital a blackbird and two ducklings. All are vulnerable to sudden cold spells. "Ducklings before Christmas is just crazy," says Lisa Frost, the research manager. She waves at the trees. "But you can see all the signs of nest building going on already." The mild winter is particularly confusing for hedgehogs. Baby hedgehogs are born in the autumn and the weaker ones weeded out by the first heavy frosts, ensuring the biggest are left to survive hibernation, when they rely upon their fat reserves. Warmer weather means that there are more weaker ones about who are not prompted into hibernating this makes them vulnerable to hazards such as sudden cold or wet spells. Ms Frost hauls one from its cage. "This one was brought in at the beginning of February, underweight and not eating. It was too small to hibernate and really should have died in the autumn."

Normally, Tiggywinkles would see only a handful of hedgehogs between January and March. This year it has had more than 80, on top of the 500 in the two months before Christmas, itself a 40 per cent increase. "It has been incredibly busy," said Ms Frost. "Usually this is a quiet period."

But Mr Stocker remains unconvinced about climate change. "If it is happening ­ and I'm not sure that this hasn't all been hyped up ­ I have great faith that nature will sort itself out and learn to live with it. After all, hibernation is a bad idea."

The global impact

* BIRDS
Migratory and breeding patterns have been thrown into confusion across Europe. Chiff-chaffs are remaining in the UK throughout the year rather than migrating south.

* FISH
Fish such as red mullet, once found only off Britain's southerly coastline, are now steadily being spotted further north, including the west coast of Scotland. Warm-water species such as tuna are being increasingly found by Cornish fishermen.

* TURTLES
Breeding grounds on beaches in the Caribbean and the Indian Ocean are under threat from rising sea levels. Water temperature affects the sex ratio, so warmer seas could mean some species becoming entirely female.

* POLAR BEARS
Their habitat of Arctic sea ice is melting away, while seals, their natural prey, are believed to be at risk from a decline in fish stocks. Polar bears are now thinner than 20 years ago.

* BUTTERFLIES
One study reports two-thirds of European butterflies have shifted their habitats north by between 20 and 150 miles.
(By Terry Kirby, The Independent, 08/03/2007)
http://news.independent.co.uk/environment/wildlife/article2338372.ece