Europe has an estimated 421 million fewer birds today than 30 years ago, with the majority of losses from the most common species such as house sparrows, skylarks and grey partridges, a new study has found.
However, the numbers of some less common birds have risen, according to researchers.
The study shows a decrease of 421 million individual birds over 30 years.
Around 90 per cent of these losses were from the 36 most common and widespread species, including house sparrows, skylarks, grey partridges and starlings, highlighting the need for greater efforts to halt the continent-wide declines of familiar countryside birds.
"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," said Richard Inger from the University of Exeter.
"It is becoming increasingly clear that interaction with the natural world and wildlife is central to human wellbeing and significant loss of common birds could be quite detrimental to human society," said Inger.
The majority of the declines can be attributed to considerable losses from relatively few common birds, but not all common species are declining, researchers said.
Numbers of great tits, robins, blue tits and blackbirds were all shown to be increasing.
Populations of rarer species, including marsh harriers, ravens, buzzards and stone curlews have also shown increases in recent years: this is likely to be the result of direct conservation action and legal protection in Europe.
"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," said researchers.
Conservation efforts tend to be focused on rarer species but the research suggests that conservationists should also address issues affecting common birds, for example those traditionally associated with farmland.
The decline in bird populations can be linked to modern farming methods, deterioration of the quality of the environment and habitat fragmentation, although the relative importance of these pressures remains unclear, researchers said.
The study brought together data on 144 species of European birds from many thousands of individual surveys in 25 different countries, highlighting the value of the different monitoring schemes increasingly working together.
The researchers suggest that greater conservation funding and effort should be directed to wider scale environmental improvement programmes.
These could include urban green space projects, and effective agri-environment schemes, which, informed by lessons learned from past schemes, should aim to deliver real outcomes for declining bird species whether they are rare or common.
The study was published in the journal Ecology Letters.
