Use of Pesticides and Herbicides Found to Be Biggest Cause of Bird Decline in Europe

A large team of ornithologists, zoologists, biologists and ecologists from across Europe and the U.K. has found that the chief cause of declining bird populations in Europe and the U.K. is the use of pesticides and herbicides by farmers. In their study, reported in Proceedings of the National Academy of Sciences, the group examined the effects of pesticides and herbicides on bird populations in a variety of locations.

Prior research has shown that the number of birds in Europe and the U.K. has fallen dramatically over the past half-century—some in the field have estimated that there are now 550 million fewer birds in Europe alone. It has been believed that the decline is due to the usual suspects: pollution and loss of habitat. In this new effort, a research team with over 50 members took a closer look to pinpoint the factors most at fault.

The work involved studying data from multiple sources, including reports by citizen scientists, in 28 countries in Europe and the U.K. over the past four decades. They not only confirmed massive drops in population numbers for most bird species, but also discovered the main culprit: use of pesticides and herbicides by farmers. These chemicals can harm birds both directly and indirectly, causing medical problems or birth defects and killing off the insects they feed on.