According to a new study (RSPB, BirdLife International and the Czech Society for Ornithology), there are now 247 million fewer house sparrows in Europe than there were in 1980, and other once "ubiquitous" bird species have also experienced significant population declines. One in six breeding birds – totalling around 600 million birds – have vanished in less than four decades. Among the best-known species that have disappeared from the skies, it is worth mentioning the yellow wagtail (down by 97 million), starlings (a decrease of 75 million), and skylarks (down by 68 million).

The study, which analysed data on 378 species (out of 445) obtained from the European Union and Great Britain, concludes that the total decline in the number of breeding birds between 1980 and 2019 is estimated to be in the range of 17-19%.

The house sparrow has suffered the hardest hit, with its population shrinking by almost 50%. Its closest relative, the tree sparrow, has seen a population drop of 30 million. The reasons vary and are thought to be primarily due to changes in agricultural methods, but the cause of the decline in house sparrow numbers in cities has not yet been precisely determined.