The latest in a number of recent studies looking at the impact of neonicotinoid pesticides has shown declining bird populations in areas where the pesticides are used in high concentrations. Neonics have already been associated with bee die-offs, and a new study published in Nature found that common bird populations such as barn swallows and starlings decreased 3.5 percent each year in areas associated with neonics use.

“It clearly demonstrates that neonicotinoid pesticides are affecting the entire food chain,” says Jonathan Evans, toxics and endangered species campaign director for the Center for Biological Diversity. “The cascading impacts of these pesticides are poisoning the food chain and causing ripples of impacts in higher level species like bird species that eat a lot of these insects.”

According to the study, the decline began during the mid-1990s, the same time that imidacloprid, of the neonicotinoid pesticide class, was introduced to the Netherlands. It goes on to explore other factors the researchers examined such as land-use changes to explain the population decline, though no other factors were supportive of their data. The study suggested “further legislation should take into account the potential cascading effects of neonicotinoids on ecosystems.”

In a statement by Bayer CropScience, producer of neonicotinoids and specifically imidacloprid, the company said the study “provides no substantiated evidence of the alleged indirect effects of imidacloprid on insectivorous birds” and that this class of pesticides is “safe to the environment when used responsibly.” Imidacloprid was one of the neonics sprayed on linden trees in a recent Eugene bee die-off.

“There is a wealth of peer-reviewed science that shows the negative effect on pollinators and other non-target species,” Evans says. “Clearly all of these products are toxic and designed to kill, and it’s a question of whether their impacts are worth overlooking in terms of their benefits to society. In terms of neonics, they are devastating the same agricultural sector that they are ostensibly benefiting by destroying the pollinator species that is the backbone of our agricultural system.”

The European Union recently put a two-year moratorium in place on neonicotonoids until further research on the impact may be completed.

“In the United States, I’m not sure why, but our pesticides really get the benefit of the doubt and are innocent until proven guilty,” says Aimee Code, pesticides program coordinator for the Xerces Society for Invertebrate Conservation. “We don’t have a smoking gun, but we have significant scientific evidence that shows us there is a serious problem that needs response. And we can’t wait until we get every last bit of data in before we act.”