Farmers’ efforts to reverse the decline of farmland birds could be at risk if government spending cuts hit conservation, according to the RSPB.

Work done to improve numbers of lapwing, skylark and other farmland birds could be hit unless policy is developed to reverse bird decline, the organisation has warned.

In a report published on Monday, the RSPB said 40 species of British wild birds were at risk from extinction unless a “strategic approach” to conserving bird numbers was developed.

The report, Safeguarding Species: a Strategy for Species Recovery, says 40 species of British bird species face extinction unless conservation efforts and research around their decline are developed.

It identifies 10 species including the cuckoo and kestrel which are declining with no apparent cause.

The reasons for the decline of another 12 species, including the house sparrow, lapwing and turtle dove are known, but possible solutions to reverse the decline need to be tested, the report says.

A further 18 species, including the bittern, red kite and the skylark have seen numbers recover, but their populations remain fragile and require further monitoring to ensure they do not fall again.

The report warns government cuts could cause current efforts to conserve priority species, including those by farmers and landowners, to fall away unless further measures to conserve them are developed.

“In hard times, we need to prioritise by working with those birds that most need the nation’s help,” said Mark Avery, RSPB conservation director.

“Today we’re calling on politicians, business leaders and charities to save these priority species for future generations to enjoy.

“Throughout history, birds like the cuckoo, house sparrow, skylark, turtle dove and the swift have been a part of our countryside.

“Now that more birds are sinking towards oblivion they need us more than ever. We want to ensure that birds have a strong future as well as a strong past.”

Dr Avery said changes in farming practice, a lack of woodland management, wetland drainage, climate change and habitat destruction were all responsible for damaging bird numbers.

The report sets out ways for each of the at risk species to be helped, including developing nature reserves and wildlife-friendly farming schemes.

“The UK recovery of birds like the Dartford warbler, red kite, stone curlew, cirl bunting and bittern have been based on a three-way partnership of government funding, conservation expertise and landowner involvement,” Dr Avery added.

“Cuts in government funding threaten to hack a leg from the stool, possibly plunging these species into crisis once more.”

Species under threat

* Birds whose decline is unexplained: Common scoter, cuckoo, hawfinch, kestrel, lesser redpoll, slavonian grebe, swift, tree pipit, whinchat and wood warbler.

* Birds whose recovery is on trial: Corn bunting, curlew, hen harrier, house sparrow, lapwing, lesser-spotted woodpecker, redshank, ring ousel, turtle dove, twite, willow tit and yellow wagtail.

* Birds that are enjoying a fragile recovery: Bittern, black grouse, black-necked grebe, black-tailed godwit, black-throated diver, capercaillie, chough, cirl bunting, corncrake, crested tit, Dartford warbler, nightjar, red kite, reed bunting, skylark, stone curlew, white-tailed eagle and woodlark.