Bird populations are drastically dropping across Europe, according to a study published Monday.
An estimated 421 million animals have been lost over 30 years, researchers at the University of Exeter wrote in the journal Ecology Letters. Evaluating 144 different species, the birds hardest hit were sparrows, partridges, skylarks and other common birds; rare avians like buzzards and harriers, on the other hand, showed an uptick in the last few years, which the scientists attribute to specific conservation efforts.
"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 University of Exeter ecology Richard Inger in a statement. Relying on survey data collected by ornithologists at the European Bird Census Council, Inger and his colleagues found that almost nine out of every 10 lost birds came from relatively abundant species. Many of the declining birds are animals at home on farmland, the scientists noted; increasingly intense agricultural practices (like multiple crops and farming year-round) could be squeezing out birds who live in these areas.