New research has identified the world’s most widely used insecticides as the key factor in the recent reduction in numbers of farmland birds.
The finding represents a significant escalation of the known dangers of the insecticides and follows an assessment in June that warned that pervasive pollution by these nerve agents was now threatening all food production.
The neonicotinoid insecticides are believed to seriously harm bees and other pollinating insects, and a two-year EU suspension on three of the poisons began at the end of 2013. But the suspected knock-on effects on other species had not been demonstrated until now.
Peer-reviewed research, published in the leading journal Nature this Wednesday, has revealed data from the Netherlands showing that bird populations fell most sharply in those areas where neonicotinoid pollution was highest. Starlings, tree sparrows and swallows were among the most affected…
The researchers, led by Hans de Kroon, an ecologist at Radboud University, in the Netherlands, examined other possible reasons for the bird declines seen during the study period of 2003 to 2010, including intensification of farming. But high pollution by a neonicotinoid known as imidacloprid was by far the largest factor.
“It is very surprising and very disturbing,” de Kroon said. Water pollution levels of just 20 nanograms of neonicotinoid per litre led to a 30% fall in bird numbers over 10 years, but some water had contamination levels 50 times higher. “That is why it is so disturbing – there is an incredible amount of imidacloprid in the water,” he said. “And it is not likely these effects will be restricted to birds.”
De Kroon added: “All the other studies [on harm caused by neonicotinoids] build up from toxicology studies. But we approached this completely from the other end. We started with the bird population data and tried to explain the declines. Our study really makes the evidence complete that something is going on here. We can’t go on like this any more. It has to stop.”
RTFa for all the details. As a modern society I expect the Netherlands will respond to scientific studies as the peer-review process continues.
Here in the land of Tea Parties and the Best Government Money Can Buy – I am less assured of any efforts to proceed with caution and a decision process based on science. But, then – you already knew that.