NOT all British wildlife is at risk because of global warming - and at least one rare wild bird is actually booming as a result, according to the Royal Society for the Protection of Birds.

As its name suggests, the Dartford warbler was once contained in a very small area of southern England. But because winters have become warmer, it has now spread to the Midlands, East Anglia and Wales.

Warmer winters mean the birds are likely to push even further north but they can only do that if there are heathland sites available

Simon Wotton - RSPB

If it is to reach northern England, however, the Government must do more to protect its habitat in areas threatened by more building development, says the society.

A joint survey by the RSPB, the British Trust for Ornithology and Natural England shows that the colourful warbler has soared in numbers by 70% since the last count in 1994. There are now more than 3,000 breeding pairs, the highest tally for almost half a century.

However, the RSPB warns that while the Dartford warbler is flying north, west and east from its strongholds in southern England, conservationists say that more is needed to protect and restore heathlands to help the bird further its advance.

Simon Wotton, Research Biologist at the RSPB, said: "This survey is fantastic news for a very vulnerable bird, particularly because it has moved to higher ground not used by Dartford warblers for many years.

"Warmer winters mean the birds are likely to push even further north but they can only do that if there are heathland sites available which are protected from development. If the government is to help wildlife adapt to climate change it should be assigning more land for the creation of habitats to help birds like these.

"The Dartford warbler is a wonderful species but its vulnerability to the cold and wet, which could still be a problem as our climate alters, means all safeguards possible must be put in place."