Poaching is a prominent source of ‘hidden hurdles’, cryptic impacts of human activities that may hinder the conservation of animal populations. Estimating poaching mortality is challenging, as the evidence for illegal killing is not outwardly obvious. Using resighting and recovery data collected on 141 marked red deer Cervus elaphus within the Stelvio National Park (central Italian Alps), we show how multievent models allow to assess the direct impacts of illegal harvesting on age- and sex-specific survival, accounting for uncertainty over mortality causes. Mortality caused by poaching was consistently higher for males than for females in all age classes. In males, the probability of dying from poaching was higher for extreme age classes, while in females all age classes showed fairly similar values of poaching mortality. The strong bias in sex-specific poaching mortality was possibly due to trophy killing in adult males and ‘bushmeat-like’ killing for private or commercial gain in young males and in females. A robust assessment of age- and sex-specific prevalence of poaching in wildlife populations is pivotal when illegal killing is of conservation concern. This provides timely information on what segment of the population is most likely to be affected. Besides obvious demographic consequences on small populations, age- and sex-biased poaching prevalence may contrast with the need to maintain ecosystem complexity and may alter behavioral responses to human presence. The information provided by multievent models, whose flexibility makes them adaptable to many systems where individual-based data is part of population monitoring, offers a support to design appropriate strategies for the conservation of wildlife populations.

中文翻译：

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通过多事件建模揭示偷猎死亡率对性别和年龄的影响

偷猎是“隐藏障碍”的一个突出来源，人类活动的神秘影响可能会阻碍动物种群的保护。估计偷猎死亡率具有挑战性，因为非法猎杀的证据并不明显。使用在 Stelvio 国家公园（意大利中部阿尔卑斯山）内对 141 只标记的马鹿 Cervus elaphus 收集的重新定位和恢复数据，我们展示了多事件模型如何允许评估非法采伐对特定年龄和性别的生存的直接影响，并解释不确定性超过死亡原因。在所有年龄段，偷猎导致的男性死亡率始终高于女性。在男性中，极端年龄组因偷猎而死亡的概率更高，而在女性中，所有年龄组的偷猎死亡率都相当相似。性别特异性偷猎死亡率的强烈偏差可能是由于成年男性的战利品猎杀和年轻男性和女性为了私人或商业利益而进行的“丛林肉样”猎杀。当非法猎杀成为保护问题时，对野生动物种群中特定年龄和性别的偷猎流行率进行强有力的评估至关重要。这提供了有关最有可能受到影响的人群的及时信息。除了对小群体的明显人口影响外，年龄和性别偏见的偷猎流行可能与维持生态系统复杂性的需要形成对比，并可能改变对人类存在的行为反应。多事件模型提供的信息，其灵活性使它们能够适应许多系统，其中基于个体的数据是人口监测的一部分，