Nelson Institute for Environmental Studies, University of Wisconsin - Madison, Madison, USA.
Sci Rep. 2022 Feb 2;12(1):1738. doi: 10.1038/s41598-022-05679-w.
Poaching is the main cause of mortality for many large carnivores, and mitigating it is imperative for the persistence of their populations. For Wisconsin gray wolves (Canis lupus), periods of increased risk in overall mortality and poaching seem to overlap temporally with legal hunting seasons for other large mammals (hunting wolves was prohibited). We analyzed monitoring data from adult, collared wolves in Wisconsin, USA (1979-2012, n = 495) using a competing-risk approach to test explicitly if seasons during which it was legal to train hunting hounds (hounding) or hunt other large mammals (hunting) affected wolves' hazard of cause-specific mortality and disappearance. We found increases in hazard for disappearances and documented ('reported') poaching during seasons with hunting, hounding or snow cover relative to a season without these factors. The 'reported poached' hazard increased > 650% during seasons with hunting and snow cover, which may be due to a seasonal surge in numbers of potential poachers or to some poachers augmenting their activities. Snow cover was a major environmental factor contributing to poaching, presumably through increased detection of wolves. Our study suggests poaching is by far the highest mortality hazard for wolves and reinforces the need for protections and policies targeting poaching of protected populations.
偷猎是许多大型食肉动物死亡的主要原因，为了维持其种群的生存，减轻偷猎的影响至关重要。对于威斯康星州灰狼（Canis lupus）来说，整体死亡率和偷猎风险增加的时期似乎与其他大型哺乳动物的合法狩猎季节（禁止猎狼）在时间上重叠。我们使用竞争风险分析方法，分析了美国威斯康星州佩戴项圈的成年狼的监测数据（1979-2012 年，n=495），以明确测试在合法训练猎犬（猎犬）或狩猎其他大型哺乳动物（狩猎）的季节是否会影响狼特定原因死亡率和失踪的风险。与没有这些因素的季节相比，我们发现狩猎、猎犬和积雪覆盖的季节中，狼失踪和记录（“报告”）的偷猎风险增加。在狩猎和积雪覆盖的季节中，“报告的偷猎”风险增加了>650%，这可能是由于潜在偷猎者数量的季节性激增，或者是一些偷猎者增加了他们的活动。积雪覆盖是偷猎的一个主要环境因素，可能是因为它增加了对狼的探测。我们的研究表明，偷猎是迄今为止对狼的最高死亡率威胁，并强调了针对受保护种群的偷猎行为采取保护和政策的必要性。
