Williams et al. - Consumption of rodenticide baits by invertebrates as a potential route into the diet of insectivores - field data and pilot data

European hedgehogs (Erinaceus europaeus) continue to experience a notable long-term decline across the UK. A key threat they face is exposure to anticoagulant rodenticides, however the pathway of exposure is currently unknown. This study aimed to examine whether invertebrate prey are a potential vector for anticoagulant rodenticides in the diet of the European hedgehog. A field study measured the uptake of rodenticide baits in invertebrates across a variety of habitats and locations. Uptake was negligible in captured insects, however 20.7% of slugs and 18.4% of snails captured showed uptake of bait. Both the percentage of and total number of molluscs showing uptake of bait significantly decreased with distance captured from the bait boxes, and increased with proximity to buildings. Maximum temperature had a significant negative impact on the percentage of molluscs showing uptake of baits, but no effect on the total number. The presence of copper tape significantly decreased the number of molluscs entering the bait boxes. Based on these data it seems likely that molluscs pose a significant threat to European hedgehogs via secondary rodenticide poisoning. This research has provided a more comprehensive idea of which prey items pose an exposure risk to hedgehogs and which environmental factors influence this; knowledge which has the potential to aid the development of effective mitigation measures. Further investigation into using mollusc repellents around bait boxes should be considered.

欧洲刺猬（Erinaceus europaeus）在英国范围内持续遭受显著的长期衰退。它们面临的关键威胁之一是暴露于抗凝性杀鼠剂，然而，暴露的途径目前尚不清楚。本研究旨在探究无脊椎动物猎物是否可能成为欧洲刺猬饮食中抗凝性杀鼠剂的潜在传播媒介。一项实地研究测量了不同栖息地和地点的无脊椎动物对杀鼠剂诱饵的摄取情况。在捕获的昆虫中，摄取量微乎其微，然而，20.7%的蛞蝓和18.4%的蜗牛在捕获时显示出诱饵的摄取。无论是摄取诱饵的蜗牛比例还是总数量，均随着与诱饵箱捕获距离的增加而显著减少，而与建筑物的接近度增加而增加。最高温度对显示出诱饵摄取的蜗牛比例产生了显著的负面影响，但对总数量没有影响。铜箔的存在显著减少了进入诱饵箱的蜗牛数量。基于这些数据，似乎可以推断蜗牛通过次级杀鼠剂中毒对欧洲刺猬构成重大威胁。本研究为哪些猎物可能对刺猬构成暴露风险以及哪些环境因素影响这一风险提供了更全面的认知；这一认知有可能帮助开发有效的缓解措施。考虑在诱饵箱周围使用蜗牛驱避剂进行进一步的研究是合理的。