SummaryPassive acoustic monitoring is rapidly gaining recognition as a practical, affordable and robust tool for measuring gun hunting levels within protected areas, and consequently for its potential to evaluate anti-poaching patrols’ effectiveness based on outcome (i.e., change in hunting pressure) rather than effort (e.g., kilometres patrolled) or output (e.g., arrests). However, there has been no report to date of a protected area successfully using an acoustic grid to explore baseline levels of gun hunting activity, adapting its patrols in response to the evidence extracted from the acoustic data and then evaluating the effectiveness of the new patrol strategy. We report here such a case in Cameroon’s Korup National Park, where anti-poaching patrol effort was markedly increased in the 2015–2016 Christmas/New Year holiday season to curb the annual peak in gunshots recorded by a 12-sensor acoustic grid in the same period during the previous 2 years. Despite a three- to five-fold increase in patrol days, distance and area covered, the desired outcome – lower gun hunting activity – was not achieved under the new patrol scheme. The findings emphasize the need for adaptive wildlife law enforcement and how passive acoustic monitoring can help attain this goal, and they warn about the risks of using effort-based metrics of anti-poaching strategies as a surrogate for desired outcomes. We propose ways of increasing protected areas’ capacity to adopt acoustic grids as a law enforcement monitoring tool.

中文翻译：

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地面上的靴子：被动声学监测在评估反偷猎巡逻中的作用

摘要被动声学监测作为一种实用、经济实惠且强大的工具正在迅速获得认可，用于测量保护区内的枪支狩猎水平，因此它有可能根据结果（即狩猎压力的变化）评估反偷猎巡逻的有效性，而不是努力（例如，巡逻公里）或输出（例如，逮捕）。然而，到目前为止，还没有关于保护区成功使用声学网格来探索枪支狩猎活动的基线水平、根据从声学数据中提取的证据调整巡逻、然后评估新巡逻策略的有效性的报告. 我们在此报道喀麦隆科鲁普国家公园的一个案例，在 2015-2016 年圣诞节/新年假期期间，反偷猎巡逻力度显着增加，以遏制前 2 年同期由 12 传感器声学网格记录的年度峰值。尽管巡逻天数、距离和覆盖面积增加了三到五倍，但在新的巡逻计划下并没有达到预期的结果——减少猎枪活动。研究结果强调了适应性野生动物执法的必要性以及被动声学监测如何帮助实现这一目标，并且他们警告使用基于努力的反偷猎策略指标作为预期结果的替代品的风险。我们提出了提高保护区采用声学网格作为执法监测工具的能力的方法。