Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, Cape Town 7701, South Africa; Cape Leopard Trust, P.O. Box 31139, Tokai, Cape Town 7966, South Africa; Environmental Studies, University of California, Santa Cruz, Campus Mail Stop, 1153 High Street, Santa Cruz, CA, USA.
Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, Cape Town 7701, South Africa.
Sci Total Environ. 2019 May 20;666:581-590. doi: 10.1016/j.scitotenv.2019.02.122. Epub 2019 Feb 13.
Anticoagulant rodenticides (ARs) are used worldwide to control rodent populations. ARs bioaccumulate across trophic levels and threaten non-target wildlife. We investigated the prevalence of AR exposure in seven predator species in the rapidly developing Greater Cape Town region of South Africa - a mosaic of natural, urban, and agricultural areas within a global biodiversity hotspot. We focused sampling on caracals (Caracal caracal, n = 28) as part of a larger caracal ecology study, but also opportunistically sampled Cape Clawless otters (Aonyx capensis, n = 9), large-spotted genets (Genetta tigrina, n = 4), honey badger (Mellivora capensis, n = 1), water mongoose (Atilax paludinosus, n = 1), small gray mongoose (Galerella pulverulenta, n = 1), and Cape Eagle owl (Bubo capensis, n = 1). We tested livers from all species, and blood from ten caracals, for eight AR compounds to assess prevalence and amount of exposure for each compound. We used generalized linear models to test spatial, demographic, and seasonal risk factors for ten measures of AR exposure in caracals. We detected at least one of the four most toxic AR compounds in six species. Exposure was high for caracals (92%) and all species combined (81%). For caracals, proximity to vineyards was the most important AR exposure risk factor. Vineyards in Cape Town do not use ARs to protect their vines but do host commercial hospitality structures where ARs are used. Vineyards may thus link caracals that forage within vineyards to the rat poisons used in and around their commercial structures. Residue levels were unexpected in large-spotted genets and Cape Clawless otters, suggesting invertebrate vectors. ARs may present a cryptic threat to populations already vulnerable to increasing habitat loss, vehicle collisions, poachers and fire. Targeted mitigation should include a mix of environmentally responsible policies that reduce AR use, particularly in areas near wildlife habitat.
抗凝血灭鼠剂（ARs）在全球范围内用于控制鼠类种群。ARs 在营养级之间生物积累，并威胁到非目标野生动物。我们调查了南非快速发展的大开普敦地区七种捕食者物种中 AR 暴露的流行情况 - 这是一个在全球生物多样性热点地区的自然、城市和农业区域的马赛克。我们专注于对卡拉卡尔（Caracal caracal）进行采样，作为更大的卡拉卡尔生态学研究的一部分，但也偶然对海角无爪水獭（Aonyx capensis）、大斑点金猫（Genetta tigrina）、蜜獾（Mellivora capensis）、水貂（Atilax paludinosus）、小灰色貂（Galerella pulverulenta）和海角鹰鸮（Bubo capensis）进行了采样。我们测试了所有物种的肝脏，以及 10 只卡拉卡尔的血液，以评估每种化合物的流行程度和暴露程度。我们使用广义线性模型测试了空间、人口统计学和季节性风险因素对 10 种 AR 暴露的卡拉卡尔的影响。我们在六种物种中至少检测到了四种最有毒的 AR 化合物中的一种。卡拉卡尔（92%）和所有物种的暴露水平都很高（81%）。对于卡拉卡尔来说，靠近葡萄园是最重要的 AR 暴露风险因素。开普敦的葡萄园不使用 AR 来保护他们的葡萄藤，但确实有商业接待结构，在那里使用 AR。因此，葡萄园可能将在葡萄园觅食的卡拉卡尔与用于其商业结构内部和周围的老鼠毒药联系起来。大斑点金猫和海角无爪水獭的残留物水平出人意料，这表明存在无脊椎动物载体。AR 可能对已经容易受到栖息地丧失、车辆碰撞、偷猎者和火灾增加的种群构成隐性威胁。有针对性的缓解措施应包括一系列减少 AR 使用的环境负责政策，特别是在靠近野生动物栖息地的地区。
