Neonicotinoid Insecticides Are Killing Songbirds

It turns out that bees and other insects are not the only victims of neonicotinoid insecticides. Songbirds and other birds are also being affected – and in much larger numbers than anyone might have expected.

In new research conducted at the University of Saskatchewan, it was revealed for the first time that two of the insecticides most broadly applied worldwide are proving highly toxic to seed-eating songbirds. Those insecticides are imidacloprid (a neonicotinoid) and chlorpyrifos (an organophosphate).

Imidacloprid is a neurotoxin that does its killing by attacking the central nervous system of insects. It is part of the neonicotinoid class of pesticides, which work by blocking transmission of stimuli in the insect nervous system, eventually causing paralysis and death. As of 1999, it was the insecticide most widely used in the world to control aphids, cane beetles, locusts and tree pests such as the emerald ash borer, fleas, Japanese beetle larvae and more.

This class of pesticides has unfortunately also been shown to pose a risk to bees and, because of its widespread use, is thought to be a major cause of what is referred to as “colony collapse disorder.”Chlorpyrifos, introduced over 50 years ago in 1965 by Dow Chemical, is used in nearly 100 countries and is applied annually to approximately 8.5 million acres of crops worldwide. Also a neurotoxin, it inhibits acetylcholinesterase. It is typically applied to kill worms and a variety of other insects. Its effects have been studied in humans, with the World Health Organization categorizing it as moderately hazardous to humans; but in high concentrations it has been linked to developmental and autoimmune disorders. Consequently, it has been phased out of all residential use in the United States.

Chlorpyrifos was so widely understood to be toxic to a broad range of species that there had been a formal administrative petition to ban its use completely in the United States. That petition, filed during the Obama administration era, had been put forth by the Natural Resources Defense Council and the Pesticide Action Network North America. When Scott Pruitt became head of the Environmental Protection Agency as part of the Trump administration, despite the many sound research studies that had suggested its toxicity, one of his first acts was to deny that petition. His action took effect on March 29, 2017.

This latest research, conducted under the direction of Christy Morrissey, a University of Saskatchewan biology professor, might become a potent force in bringing those petitions back again. Detailed research conducted by Margaret Eng, a post-doctoral fellow working in Morrissey’s area, showed that seed-eating songbirds are being significantly affected by the two pesticides under review. As Eng said in discussing the study results, “These chemicals are having a strong impact on songbirds. We are seeing significant weight loss and the birds’ migratory orientation being significantly altered.” One reason why the current study is especially timely is that recent technology shifts in how the pesticide is propagated are making the seeds inherently more toxic to songbirds. As lead researcher Morrissey said, “In the past, farmers might have placed an insecticide into a crop duster and would spray their fields with the insecticide. However, now farmers have access to seeds that in many cases are already coated with neonicotinoids.”

The University of Saskatchewan research was conducted during a spring migration period. The scientists captured sparrows and fed them daily for three days with either low or high doses of imidacloprid or chlorpyrifos. After feeding the birds in this way, the scientists found that the neonicotinoids ended up altering the birds’ migratory orientation and were tied to losses of up to 25% of their fat stores and body mass. The loss of orientation and body mass caused major havoc with the birds’ ability to migrate successfully, with flying range diminished and the birds even losing their proper northward orientation during migration. Missing proper migration routes could create missed breeding opportunities and even death.

As the researchers noted, many small migratory songbirds use agricultural land as part of their migration route, both for rest as well as building up fat stores. The effects were noted not just with neonicotinoid diets but also with chlorpyrifos-laced ones as well. Shocking was that the effects on migration direction and fat stores occurred after eating as few as “just three or four imidacloprid treated canola seeds or eight chlorpyrifos granules a day for three days,” according to Morrissey.

The study may become better known very soon, as a proposed imidacloprid ban is currently under review in Canada. There, the government is expected to decide on possible regulatory changes in how that pesticide can be applied, possibly including a complete ban on its use across the country by the end of 2017.

This research was conducted at the University of Saskatchewan’s Facility for Applied Avian Research (FAAR), a research center focused on avian health and ecotoxicology. It is the only such facility of its kind in Western Canada. Unfortunately, the university also has a close relationship with the agrochemical industry.

Needless to say, if the insecticides are negatively impacting insects and birds, they are also likely making humans sick as well.

Fortunately, by consuming organically grown food instead of that which is laced with dangerous poisons, we can choose to not poison our bodies and our planet.