Europe has an estimated 421 million fewer birds today than it did 30 years ago, a study has found.
Around 90 per cent of the losses have affected the most common and widespread species, including sparrows, skylarks, grey partridges and starlings.
Scientists believe the population crash can be linked to modern farming methods and deteriorating and fragmenting habitats.
Richard Inger, one of the researchers from the University of Exeter, said: “It is very worrying that the most common species of bird are declining rapidly because it is this group of birds that people benefit from the most.
“It is becoming increasingly clear that interaction with the natural world and wildlife is central to human well-being, and significant loss of common birds could be quite detrimental to human society.”
Not all common birds are declining. Populations of great tits, blue tits, robins and blackbirds, are all going up, the study found.
Rare species such as marsh harriers, ravens, buzzards, storks and stone curlews had also shown increases in recent years, probably due to conservation efforts.
The research, co-led by the Royal Society for the Protection of Birds (RSPB), is published in the journal Ecology Letters.
Significant loss of common birds could be quite detrimental to human society
Richard Gregory, from the RSPB’s Centre for Conservation Science, said: “The rarer birds in this study, whose populations are increasing, have benefited from protection across Europe. For example, white storks and marsh harriers receive among the highest level of protection in the EU − this is why their numbers have increased. The conservation and legal protection of all birds and their habitats in tandem are essential to reverse declines.
“This is a warning from birds throughout Europe. It is clear that the way we are managing the environment is unsustainable for many of our most familiar species.”
The scientists analysed data on 144 species of European birds collected from numerous surveys in 25 different countries.
Much of the information was provided by thousands of volunteer fieldworkers who identified and counted birds in the areas where they lived.
More conservation should be directed at wider-scale environmental improvement, said the researchers.
These could include urban green space projects and effective environmental schemes aimed at farmland.