Dorset heathlands’ Dartford warblers appear to have bucked the trend and survived against the odds.

A report from the Rare Breeding Birds Panel paints a bleak picture for the colourful little bird, which has suffered a dramatic decline at some of its most important breeding sites.

But while the harsh winters leading up to 2010 have seen declines from 1,000 pairs in the Thames Basin in 2004 to just 50 pairs across Berkshire, Hampshire, Surrey and Sussex in 2010, the picture is different in Dorset.

At the RSPB’s Arne reserve on the Purbeck edge of Poole Harbour , numbers are up again this year, for the bird which in Britain is at the northern edge of its range, says Rob Farrington, visitor manager.

“In the last few years we’ve gone from 55 pairs to 22 pairs, after that bad winter two years ago.

“Now the population is recovering back up to 30 odd pairs.”

The RBBP report has better news for the firecrest, one of the UK’s smallest birds, which is increasingly nesting in southern England, where there may be more than 1,000 pairs.

“We have had at least five pairs breeding at Arne this year, that’s a first,” said Rob.