Research roundup: How do pesticides affect the health of grain-eating birds?

February 10, 2020

Imidacloprid, a pesticide often used on soybeans, is one of seven types of neonicotinoids available to farmers right now, and almost all agricultural seeds are treated with some type of neonicotinoid. A team of researchers — led by Dana Franzen-Klein, DVM, MS, staff veterinarian at the University of Minnesota College of Veterinary Medicine's Raptor Center — recently studied the negative effects imidacloprid could have on chickens as a model for wild grain-eating birds, such as grouse. Studies have previously identified lethal levels of imidacloprid in some bird species, but this project, which included researchers from the Minnesota Department of Natural Resources and the US Environmental Protection Agency, aimed to more specifically pinpoint how much of the substance a bird would need to ingest to exhibit clinical signs, as well as measure the intensity of those signs as dosages increased. The scientists saw clinical signs — which depended on the dosage and included mild depression, whole-body muscle tremors, and a lack of response to external stimuli — develop within as little as five minutes of the pesticide hitting the birds’ stomachs. These findings provide information that can be used to develop risk assessment tools to predict what could happen when wild grain-eating birds interact with this pesticide. Although the scientists suspect imidacloprid’s effects would be unlikely to transfer up the food chain, they say that more specific research into this area is needed. Next steps include studying the interface between wild birds and agriculture to determine which wild bird species are being exposed to imidacloprid, and how much of the pesticide they are exposed to.

Read more in the Journal of Toxicology and Environmental Health