Photo © Jim Williams

What are neonicotinoids and what do they have to do with birds? Neonicotinoids — sometimes called neonics — are the most widely used class of insecticides in the world. But like the infamous insecticidal scourge of the 1970s, DDT, evidence is building that neonicotinods are harming birds, pollinators, and our food supply.

What’s Going On?

First introduced in the early 1990s, neonicotinoids account for one-third of the insecticide market. Their popularity is twofold: they are effective against insects resistant to previous pesticides and reportedly safer than organophosphate-based compounds.

But they just might be the next DDT. Already blamed for widespread bee declines, early scientific evidence suggests that neonicotinoids are also irreparably harming bird populations.

Birds can be exposed to these pesticides in several ways, including eating pesticide-coated seeds. Most neonicotinoids are applied by coating seeds with the neurotoxin before planting. A single neonicotinoid-coated seed can be fatal for an average sized bird, according to a report by the American Bird Conservancy. Neonicotinoids are also highly water soluble and slow to biodegrade, so they can contaminate surface water supplies and build up in sediments or soils.

What the Science Says

Scientists in the Netherlands found that bird populations plummeted as concentrations of neonicotinoids in local surface water rose. In places where the water contained high concentrations of a common neonicotinoid, imidacloprod, bird populations declined by an average of 3.5 percent each year. Published in Nature, their study is the first to link bird declines with neonicotinoid insecticide use.

Scientists also suspect that neonicotinoids are triggering other global-scale wildlife declines, besides birds and bees. Previous research indicates that these insecticides suppress honeybees’ immune response to infection. In a 2013 literature review in the Journal of Environmental Immunology and Toxicology, researchers hypothesize that the same effect could be causing catastrophic population declines of other pollinators, amphibians, fish, and bats. Possible neonicotinoid-fueled epidemics include chytridiomycosis, which threatens hundreds the world’s amphibians, and white-nose syndrome, which is responsible for an estimated 5.7 million bat deaths across North America.

Why It’s Important

Neonicotinoids threaten the health of wild bird populations, jeopardizing existing conservation efforts to protect the world’s 1,373 threatened bird species.

Decline in wild bird populations will also jeopardize the positive impact that birding has on local economics. In the United States, trip and equipment-related expenditures associated with birding generated nearly $107 billion, an estimated 666,000 jobs, and approximately $13 billion in local, state, and federal tax revenue, according to a U.S. Fish and Wildlife Service report.

Finally, neonicotinoids’ effect on bees and other pollinators could also negatively affect agriculture. Scientists warn that these insecticides are likely “having major negative effects on ecosystem services such as pollination that are vital to food security and sustainable development.” For example, crops pollinated by honeybees and other insects contributed an estimated $29 billion to U.S. farm income in 2010, according to a 2012 study by Cornell scientists. 

The Bottom Line

Neonicotinoids — the most widely used insecticide in the world — are causing significant and harmful declines in global biodiversity and food security. Concerned scientists are calling for a dramatic reduction in neonicotinoid use and a shift to more sustainable methods of pest control and food production.

Justine E. Hausheer

Justine E. Hausheer is an award-winning science writer for The Nature Conservancy, covering the innovative research conducted by the Conservancy’s scientists in the Asia Pacific region. She has a degree from Princeton University and a master's in Science, Health, and Environmental Reporting from New York University. Justine's favorite stories take her into pristine forests, desolate deserts, or far-flung islands to report on field research as it's happening. When not writing, you can find her traipsing after birds, attempting to fish, and exploring the wild places around her home in Brisbane, Australia. More from Justine

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  1. It is a better concept to work with nature, than have chemical production for use of pesticides. For instance, birds are very helpful for cleaning out bugs in the garden, but when necessary, bird netting keeps them out. Birds eating habits and flight patterns also spread and plant fruit trees and berry bushes. It seems better to have birds alive and working for us. What kills birds is probably killing us. It seems Nihilistic to encourage the use of chemicals to kill this that and the other thing. In the Earth’s future, neurotoxic solutions in layers of plastic with mutated human skeletons will be a problem for future sanity.

  2. What exactly should we be avoiding? How do I know if seeds are treated with neonicotinoids? I have noticed fewer and fewer milkweed in local wildlife areas . What could be the cause other thanneonicotinoids?