Common species crumble
While the declines are worrying, they would have been much worse if other species hadn’t increased in numbers.
Collectively, more species in the study increased in number than they declined, with 203 species increasing by 341 million individuals. The black cap has seen the largest increase, with 55 million, while there are now around 29 million more blackbirds than 40 years ago.
The researchers said the increases were due to habitat conservation efforts, which have seen the EU’s protected reserves increase by more than 1.3 million square kilometers since 1993, about 800 times the size of London. Targeted action for rare species has paid off, with species such as birds of prey increasing their populations.
But focusing conservation efforts on rare and iconic species may have come at the expense of common birds like the sparrow, with abundant species experiencing the most marked population declines.
Scientists say these losses could indicate greater damage to ecosystems, as abundant species contribute more to some services than less common ones. For example, more birds mean more insect pests can be eaten, or more seeds are spread to encourage plant growth.
This could have effects on agriculture and other industries we depend on, with BirdLife International, a conservation group that contributed to the study, calling for urgent action to protect biodiversity ahead of the next United Nations conference. on biodiversity, COP15.
The acting head of the organization for conservation in Europe, Anna Staneva, said: âThis report shows loud and clear that nature is sounding the alarm bells. While protecting already rare or endangered birds has resulted in successful recoveries, this does not appear to be sufficient to maintain populations of abundant species.
âCommon birds are becoming less and less common, in large part because the spaces they depend on are being wiped out by humans. Nature has been eradicated from our farmlands, our sea and our cities. Governments across Europe must set legally binding targets for nature restoration, otherwise the consequences will be severe, including for our own species. ‘