Neonicotinoid pesticides are applied to seeds and are known to cause lethal and sub-lethal effects in birds and mammals. Neonicotinoid-treated seeds could be available to wildlife through spillage or exposed seeds near or at the soil surface due to incomplete or shallow drilling. We quantified seed spills that may occur during loading or refilling the hopper at a landscape-scale using road-based surveys. We also quantified undrilled seeds in 1-m2 frames on the soil in the center and corner of fields to obtain estimates at the field scale. We broadcast seeds on the soil surface of a tilled field and left them for 0, 1, 2, 4, 8, 16, and 30 days to quantify neonicotinoid decrease under field conditions. Lastly, we documented wildlife at neonicotinoid-treated seed spills with trail cameras. We estimated the number of spills during planting to be 3,496 (95%CI: 1,855–5,138) and 2,609 (95%CI: 862–4,357) for corn, 11,009 (95%CI: 6,950–15,067) and 21,105 (95%CI: 6,162–36,048) for soybean, and 830 (95%CI: 160–1,500) and 791 (95%CI: 0–1,781) for wheat in 2016 and 2017, respectively. Exposed seeds were present at the soil surface in 35% of 71 fields. The probability that seeds were present on the soil surface was higher for soybeans (18.8 and 49.4% in the center and corners, respectively) than for corn (1.6 and 2.7%, respectively), and seed densities were also higher (1.04 vs 0.07 seeds/m2, respectively). Neonicotinoids decreased rapidly on seeds on the soil surface but persisted as long as 30 days. Over a dozen species of birds and mammals consumed seeds at simulated spills, with an average time for birds to find spills of 1.3 ± 1.5 days and an average time to consumption of 4.1 ± 3.4 days. Seeds are abundant on the soil surface for wildlife to consume during the spring planting season and should be considered in pesticide risk assessments. This dataset is not publicly accessible because: These data were generated by a non-EPA entity and that entity prefers to provide the data to the public using their procedures. A point of contact is provided in this record. It can be accessed through the following means: Please contact the primary author for these data. Dr. Charlotte Roy of the Minnesota Department of Natural Resources.
Email address: [email protected]. Format: The data are housed in Excel spreadsheets. Citation information for this dataset can be found in the EDG's Metadata Reference Information section and Data.gov's References section.