U.S. Geological Survey, Eastern Ecological Science Center, 12100 Beech Forest Road, Laurel, MD, 20708, USA.
U.S. Geological Survey, Eastern Ecological Science Center, c/o BARC-East, Building 308, 10300 Baltimore Avenue, Beltsville, MD, USA.
Environ Sci Pollut Res Int. 2022 Oct;29(49):74024-74037. doi: 10.1007/s11356-022-20881-z. Epub 2022 May 28.
An important component of assessing the hazards of anticoagulant rodenticides to non-target wildlife is observations in exposed free-ranging individuals. The objective of this study was to determine whether environmentally realistic, sublethal first-generation anticoagulant rodenticide (FGAR) exposures via prey can result in direct or indirect adverse effects to free-flying raptors. We offered black-tailed prairie dogs (Cynomys ludovicianus) that had fed on Rozol® Prairie Dog Bait (Rozol, 0.005% active ingredient chlorophacinone, CPN) to six wild-caught red-tailed hawks (RTHA, Buteo jamaicensis), and also offered black-tailed prairie dogs that were not exposed to Rozol to another two wild-caught RTHAs for 7 days. On day 6, blood was collected to determine CPN's effects on blood clotting time. On day 7, seven of the eight RTHAs were fitted with VHF radio telemetry transmitters and the RTHAs were released the following day and were monitored for 33 days. Prothrombin time (PT) and Russell's viper venom time confirmed that the CPN-exposed RTHAs were exposed to and were adversely affected by CPN. Four of the six CPN-exposed RTHAs exhibited ptiloerection, an indication of thermoregulatory dysfunction due to CPN toxicity, but no signs of intoxication were observed in the reference hawk or the remaining two CPN-exposed RTHAs. Of note is that PT values were associated with ptiloerection duration and frequency; therefore, sublethal CPN exposure can directly or indirectly evoke adverse effects in wild birds. Although our sample sizes were small, this study is a first to relate coagulation times to adverse clinical signs in free-ranging birds.
评估抗凝杀鼠剂对非靶标野生动物危害的一个重要组成部分是观察暴露于野外的自由活动个体。本研究的目的是确定通过猎物进行环境现实的、亚致死剂量的第一代抗凝杀鼠剂（FGAR）暴露是否会对自由飞行的猛禽造成直接或间接的不良影响。我们给曾食用 Rozol®草原犬鼠饵剂（Rozol，0.005%有效成分氯鼠酮，CPN）的黑尾草原犬鼠提供了 6 只野生红尾鹰（RTHA，Buteo jamaicensis），也给未接触 Rozol 的黑尾草原犬鼠提供了另外 2 只野生红尾鹰 7 天。在第 6 天，采集血液以确定 CPN 对凝血时间的影响。在第 7 天，将 8 只 RTHA 中的 7 只安装了甚高频无线电遥测发射机，第二天将 RTHA 释放，并监测了 33 天。凝血酶原时间（PT）和响尾蛇毒素时间证实，暴露于 CPN 的 RTHA 暴露于 CPN 并受到 CPN 的不利影响。在 6 只暴露于 CPN 的 RTHA 中，有 4 只出现了羽冠竖立，这表明由于 CPN 毒性导致体温调节功能障碍，但在参考鹰或其余 2 只暴露于 CPN 的 RTHA 中未观察到中毒迹象。值得注意的是，PT 值与羽冠竖立的持续时间和频率有关；因此，亚致死剂量的 CPN 暴露可以直接或间接引起野生鸟类的不良影响。尽管我们的样本量较小，但本研究首次将凝血时间与自由放养鸟类的不良临床症状联系起来。
