No Causal Link Between Decline in Insectivorous Birds and Use of Neonicotinoids

July 8, 2014

RESEARCH TRIANGLE PARK, N.C. (July 9, 2014) – A letter by a group of scientists on declines in insectivorous birds prepared for “Nature” does not demonstrate that there is a causal link between the use of neonicotinoids and the development of bird populations in Europe. Neonicotinoids have gone through an extensive risk assessment which has shown that they are safe to the environment when used responsibly according to the label instructions.

The letter makes no proper attempt to account for other possible sources of the reported decline such as climate change or nutrition. On the latter, two of the authors, van Turnhout and Foppen, in 2010 actually concluded that “trophic mismatches may have become a major cause for population declines in long-distance migrants in highly seasonal habitats.” The authors’ conclusion was for forests but agricultural areas are even more seasonal.

The authors’ assertions ignore the fact that most of the bird species mentioned are not foraging to a large extent on insects emerging from water bodies. Skylarks, for instance, predominantly feed on ground dwelling beetles. Birds living close to aquatic habitats – the species hypothetically affected most by concentrations of neonicotinoids in surface water – show no or negligible negative impact.

The letter refers to a publication by van Dijk et al (2013) as scientific source which was recently rebutted by peer scientists on methods used and conclusions reached. In addition, the Dutch authority responsible for authorization of crop protection products, Ctgb, concluded “that this study cannot be used to show a causal relationship between the concentration on imidacloprid and the number of observed species.”

In conclusion, the letter to “Nature” provides no substantiated evidence of the alleged indirect effects of imidacloprid on insectivorous birds. Bayer CropScience is working with the Dutch authorities and agricultural stakeholders to ensure the safe use of imidacloprid-containing crop protection products and to preserve the environment.

About Bayer CropScience

Bayer is a global enterprise with core competencies in the fields of health care,agriculture and high-tech materials. Bayer CropScience, the subgroup of Bayer AG responsible for the agricultural business, has annual sales of EUR 8,819 million (2013) and is one of the world’s leading innovative crop science companies in the areas of seeds, crop protection and non-agricultural pest control. The company offers an outstanding range of products including high value seeds, innovative crop protection solutions based on chemical and biological modes of action as well as an extensive service backup for modern, sustainable agriculture. In the area of non-agricultural applications, Bayer CropScience has a broad portfolio of products and services to control pests from home and garden to forestry applications. The company has a global workforce of 22,400 and is represented in more than 120 countries. This and further news is available at:


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Beth Roden
Head of Communications & Bayer CropScience NA Coordinator
Bayer CropScience
Tel: (919) 549-2030
Email: beth(dot)roden(at)bayer(dot)com

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