Study Points to Neonicotinoids as Major Factor in Bird Biodiversity Decline
A new study from the University of Illinois points to increased use of neonicotinoid insecticides as a major factor in the decline of bird biodiversity in the United States. The study, published in Nature Sustainability, tracked the pesticide’s impact on birds at a national scale over seven years, using data from hundreds of bird species classified as grassland birds, non-grassland birds, insectivores, and non-insectivores. “We found robust evidence of the negative impact of neonicotinoids, in particular on grassland birds, and to some extent on insectivore birds after controlling for the effects of changes in land use,” said study co-author Madhu Khanna. Specifically, the authors found that an increase of 100 kilograms in neonicotinoid usage per county—a 12% increase on average—contributed to a 2.2% decline in populations of grassland birds and 1.6% in insectivorous birds.