Birds in most trouble include iconic species like the grey partridge, lapwing, turtle dove, starling, skylark, and corn bunting.
Populations of birds in farmland and woodlands are continuing to decline, official figures show.
Birds which breed and feed on the 75 percent of UK land which is farmed have seen declines of 55 percent since the 1970s, with the majority of the falls taking place between the late 1970s and 1980s as farmland management changed.
Over the shorter term, figures from the Environment Department (Defra) which monitor 19 species of farmland birds, show a fall of six percent between 2012 and 2017.
Woodland birds have seen numbers fall by 29 percent since 1970, the figures show. In the shorter term, the data examining 37 birds which make their home in woodland, shows populations have declined by eight percent between 2012 and 2017.
The analysis from Defra said many farmland bird species were hit by agricultural changes such as the loss of mixed farming, a move from spring to autumn sowing of arable crops, change in grassland management, increased pesticide and fertiliser use, and the removal of hedgerows.
Corn buntings, grey partridges and tree sparrows, all of which are highly dependent on farmland, have experienced declines of more than 90% since 1970, while two others, stock doves and goldfinches, have seen numbers double.
Turtle doves have seen their numbers halve in the five year period of 2012 to 2017, with long term declines of 98% for the species celebrated in poetry and song.
The RSPB's head of monitoring conservation science Professor Richard Gregory said: "The relentless decline of farmland bird populations in the UK continues, the latest government statistics show the Farmland Bird Index down by 55 percent since 1970.
"Birds in most trouble include iconic species like the grey partridge, lapwing, turtle dove, starling, skylark, and corn bunting. For many of these birds, there is a simple relationship between their fortunes and modern farming practices.
"The way we manage our land must change significantly so that farming can deliver the healthy food we need, but also deliver more for nature and contribute to climate change mitigation at the same time."
Dr David Noble, principal ecologist at the British Trust for Ornithology (BTO), said: "Despite a wide range of pressures continuing to affect many of our UK bird populations, and driving declines in many of our habitat specialists, there are a few positive stories where species could be responding to more nature-friendly management and spreading northward to suitable landscapes."
He said that in the short term, birds such as skylarks and corn buntings have shown increases while lapwings have remained stable, but grey partridge populations are still in decline and showing no sign of recovery.
While more than half the woodland bird species monitored are showing declines, there were still small glimmers of hope in the woods, the BTO said. Song thrushes are showing a 22 percent increase in the short term, against a backdrop of long-term declines.
Emily Beament is the PA environment correspondent. Image: Mike Pennington.