Data from: Risk assessment of pesticide seed treatment for farmland birds using refined field data.

1.Due to reductions in winter food resources, newly sown cereal seeds have become a key component of many bird species’ diet, but these seeds are often treated with pesticides that may cause toxic effects. To complete an appropriate risk assessment, data on treated seed toxicity need to be combined with information about the risk of exposure of birds in the field and the factors that modulate such exposure.
2.We studied the abundance of pesticide-treated seeds available for birds in the field, the pesticides and their concentrations in treated seeds, and the bird species observed in the field that were feeding on these pesticide-treated seeds. The exposure of red-legged partridge to treated winter cereal seeds was characterized through the analysis of crop and gizzard contents of hunted individuals (n=189). Moreover, we measured the contribution of cereal seeds in the autumn–winter diet of partridges in order to assess the potential risk of exposure to pesticide-treated seeds.
3.Density of treated seeds on the soil surface after sowing (11.3 ± 1.2 seeds m−2 in the centre of field and 43.4 ± 5.5 seeds m−2 in the headlands) was enough to provide, in an area between 6 and 50 m2, doses of six active ingredients above those indicating acute (i.e. a dose capable of killing 50% of individuals of a sensitive species) and chronic (no observed effect level) toxicity.
4.Up to 30 bird species were observed consuming treated cereal seeds in recently sown fields. Corn bunting was identified as an appropriate focal passerine species for the risk assessment of pesticide-treated seeds.
5.We found that treated seeds were an important route of pesticide ingestion for red-legged partridge; pesticide residues (six fungicides and two insecticides) were found in 32.3% of crops and gizzards. Cereal seeds represented more than half (53.4 ± 4.3%) of total biomass consumed by partridges from October to February.
6.Synthesis and applications. The field exposure data combined with previous studies about the toxicity to partridges of using pesticide-treated seeds point to an unacceptable risk of this practice to farmland birds. Our results suggest that the prophylactic use of pesticide-coated seeds should be avoided, with the approval of this treatment considered on a case-by-case basis and accompanied with specific measures to minimise risks of adverse effects on avian communities.

1. 由于冬季食物资源减少，新播谷类种子已成为众多鸟类的关键食物来源，但这类种子常经农药包衣处理，可能产生毒性效应。为开展恰当的风险评估，需将农药包衣种子的毒性数据，与野外鸟类暴露风险及调控该暴露的相关因素信息相结合。
2. 本研究针对野外可供鸟类取食的农药包衣种子丰度、包衣种子中的农药种类及其浓度，以及野外观测到的取食该类种子的鸟类物种展开调查。通过分析狩猎个体（n=189）的嗉囊与肌胃内容物，明确了红腿鹧鸪暴露于冬季谷类包衣种子的情况。此外，本研究还测定了谷类种子在鹧鸪秋冬季饮食中的占比，以评估其暴露于农药包衣种子的潜在风险。
3. 播种后土壤表面的包衣种子密度（田块中心为11.3±1.2粒·m⁻²，田埂为43.4±5.5粒·m⁻²）足以在6至50平方米的区域内，提供超过急性（即可导致敏感物种50%个体死亡的剂量）与慢性（未观察到效应水平）毒性阈值的6种有效成分剂量。
4. 观测到多达30种鸟类在新近播种的农田中取食谷类包衣种子，其中黍鹀被确定为农药包衣种子风险评估的合适雀形目指示物种。
5. 研究发现，包衣种子是红腿鹧鸪摄入农药的重要途径；32.3%的嗉囊与肌胃样本中检出了农药残留（6种杀菌剂与2种杀虫剂）。10月至2月期间，谷类种子在鹧鸪总摄食生物量中的占比超过一半（53.4±4.3%）。
6. 综合与应用：本研究的野外暴露数据结合既往关于农药包衣种子对红腿鹧鸪毒性的研究表明，该耕作方式对农田鸟类存在不可接受的风险。本研究结果提示，应避免预防性使用农药包衣种子，该处理方式的审批需采用个案评估原则，并配套特定措施以降低对鸟类群落的不良影响风险。