Farmland birds in Britain have declined to their lowest numbers ever recorded, despite efforts in some parts of the country to protect them from damaging changes to their habitats.
The number of birds that forage and nest on farmland has fallen 52% overall in the past 40 years, with some species, including turtle doves, grey partridges, starlings, tree sparrows and corn buntings down more than 80% over the same period.
The turtle dove is now the UK’s most threatened farmland bird and in danger of being wiped from the British landscape entirely, conservationists said.
Other farmland species, including yellow wagtails, lapwings and greenfinches, are also in worrying decline. While most species are suffering from changes in land use and farming practices, the greenfinch is falling victim to the disease trichomoniasis.
“The decline of the turtle dove is particularly worrying,” said Martin Harper, conservation director at the Royal Society for the Protection of Birds (RSPB). “This is a beautiful bird which has an iconic connection with the British rural landscape and we are only now starting to discover what is causing its population to plummet so alarmingly.”
More intense and efficient farming has hit birds that eat seeds from crops and farmland weeds, particularly over the winter months, even as some farmers have tried to limit the damage by planting wildflower margins and skylark plots, leaving stubble unploughed over the winter, and by not overgrazing their land.
Numbers of goldfinches increased most on farmland, with whitethroats, stock doves, wood pigeons and jackdaws all seeing small rises.
The bleak picture is revealed in the latest UK Wild Bird Indicators, published on Wednesday by the Department for Environment, Food and Rural Affairs (Defra), the RSPB and the British Trust for Ornithology. The report shows that populations of British birds remained fairly stable overall between 1970 and 2010, but highlights huge variations between wetland, woodland, farmland and sea birds.
“Almost all of this information is collected by volunteers,” said David Noble of the British Trust for Ornithology. “We are seeing more communities with large numbers of generalist species, while specialist birds are disappearing.”
Numbers of woodland birds have dropped by a fifth since 1970, but there were winners and losers within the group. Seven species, including nightingales, wood warblers and willow tits, fell by 70%, while populations of green woodpeckers, blackcaps and sparrowhawks more than doubled.
The driver for the overall reduction in woodland birds is uncertain, but conservationists point to a decline in woodland management, overgrazing by deer and the ageing of woodlands as major factors.
The warming climate appeared to be taking a toll on some species. Though seabirds are up 30% on their numbers in 1970, some fared much worse than others. Of most concern are kittiwakes, which declined 34% in Britain, and are suffering a similar fate across continental Europe. The declines have been linked to warmer sea surface temperatures that have shifted bands of plankton in the North Sea, leading to a fall in sand eels that the birds feed on.
Arctic skuas did well between 1970 and 1985, but their populations have since fallen by half. Guillemots fared better, rising 168% over the period.
Some of the greatest increases were among birds that overwinter in Britain, but these are temporary residents and rises in this country are likely to correspond to falls elsewhere. Among wintering wildfowl, numbers of Svalbard light bellied brent geese rose 21-fold, while avocets, a species of wader, increased 41-fold.
Harper said the government’s enthusiasm for new building projects, emphasised in George Osborne’s autumn statement on Tuesday, posed a major new threat to wild birds that are already suffering from worsening habitats and the loss of dietary staples.
“We should welcome the increase of some species, but we seem to be facing a growing number of threats. The chancellor’s determination to rip up the environmental rule book drove a particularly icy blast across an increasingly bleak landscape for wildlife,” Harper said.