Efforts to save the bittern and stone curlew in East Anglia are among the success stories described in a major report on UK bird life, published today.

But the report makes depressing reading for bird-lovers, revealing that the overall number of species in trouble has risen and that the UK has failed to meet key European Union targets on biodvisersity.

The country failed to halt the loss of biodiversity by 2010, designated as International Year of Biodiversity, and has also failed to slow the rate of biodiversity loss.

Publication of the report, drawn up by a coalition of conservation organisations, comes ahead of next week's world biodiversity conference in Nagoya, Japan, at which new targets will be set.

An assessment of 232 UK bird populations carried out before 1994 showed that 38 of those were declining se-verely, but since then that number has risen by 18 per cent, with 45 populations declining.

Targets were originally set following the Earth Summit in Rio de Janeiro in 1992, and in 1994 the UK government identified 26 species of bird that were most in need of conservation help,

Of these, 24 were monitored. The number in steep decline has now more than halved, and the number increasing has risen from four to six.

Nine of the species formerly in decline have shown stable or increasing population trends, suggesting their decline has at least been halted.

Both the bittern and the stone curlew populations have increased thanks to targeted conservation action.

Stone curlews were in decline because of the loss of habitat, largely caused by changes in farming practices. Measures to save the species included locating nests and chicks on farm fields, alerting farmers to their presence and either delaying operations or lifting chicks until operations were completed.

Breckland, and in particular Weeting Heath on the Norfolk/Suffolk border, remains one of the best places to see the birds.

The bittern, one of the UK's most threatened birds, was extinct by 1886 and only returned in the early 20th century, coming near to extinction again in the mid-1990s.

Efforts to restore dry reedbeds and create new areas of wet reedbeds paid off with the bittern population making a dramatic recovery. The Suffolk coast, the Broads and the Fens are among the best places to see the bird.

Dr David Noble of the Thetford-based British Trust for Ornithology, said the UK's failure to meet the targets was concerning.

'It's bad news. The targets were always going to be difficult to hit. It's particularly of concern if biodiversity isn't high enough on the agenda of governments,' he said.

'Although we've had these successes, other things have happened. We must be very alert and keep monitoring populations to see new problems that are arising.'

Dr Mark Avery, the RSPB's conservation director, said: 'Without doubt, some of the UK's most threatened birds are in a much better state than they were in the middle of the last decade.

'Bitterns are nesting across more of the UK and the recovery of the corncrake looks promising. Thanks to the efforts of farmers, the prospects for the skylark are looking a little brighter, too.

'However, as more species are added to the endangered list, we are now faced with the twin challenges of helping more wildlife to thrive, while realising that the conservation coffers will be severely stretched over the foreseeable future.'

Have you got a story about nature or the environment for the Evening News? Contact environment correspondent Jon Welch on 01603 772476 or email jon.welch@archant.co.uk.