Biodiversity: Popular insecticides harm birds in the United States
Nature Sustainability
August 11, 2020

The increased use of neonicotinoid pesticides in the continental United States may have impacted bird populations and reduced bird diversity, according to a paper published this week in Nature Sustainability.
Bird biodiversity is declining at a marked rate. Bird populations in the United States have decreased by 29% since 1970, which has been attributed to various factors including the increased use of pesticides in agricultural production. Nicotine-based pesticides — known as neonicotinoids — have been used increasingly in the United States over recent decades. Previous research has shown that neonicotinoids are potentially toxic to birds and other non-target species. However, the impact of these pesticides on bird diversity in the United States is unclear.
Madhu Khanna and colleagues studied the effects of neonicotinoids on birds in the United States from 2008–2014. They analysed data from the North American Breeding Bird Survey to identify county-level changes for four different bird species groups — grassland birds, non-grassland birds, insectivorous birds and non-insectivorous birds — and combined this with county-level data on pesticide use.
The authors found that an increase of 100 kg in neonicotinoid usage per county, a 12% increase on average, contributes to a 2.2% decline in populations of grassland birds and 1.6% in insectivorous birds. By comparison, the use of 100 kg of non-neonicotinoid pesticides was associated with a 0.05% decrease in grassland birds and a 0.03% decline in non-grassland birds, insectivorous birds and non-insectivorous birds. Since impacts accumulate, the authors also estimate that, for example, 100 kg neonicotinoid use per county in 2008 reduced cumulative grassland-bird populations by 9.7% by 2014. These findings suggest that neonicotinoid use has a relatively large effect on population declines of important birds and that these impacts grow over time. The authors also found that the adverse impacts on bird populations were concentrated in the Midwest, Southern California and Northern Great Plains.
doi: 10.1038/s41893-020-0582-x
Research highlights
-
Jan 15
Environment: Seagrass meadows may facilitate marine plastic removal from the seaScientific Reports
-
Jan 15
Planetary Science: Mercury may have shrunk less than previously thoughtCommunications Earth&Environment
-
Jan 13
Environment: Polyester fibres found to be widespread in the ArcticNature Communications
-
Dec 23
Planetary science: Over 100,000 new craters identified on the MoonNature Communications
-
Dec 22
Conservation: Agricultural expansion could cause widespread biodiversity declines by 2050Nature Sustainability
-
Dec 18
Geology: Alpine summits may have been ice-free during life of Tyrolean IcemanScientific Reports