Office of Applied Sciences, Wisconsin Department of Natural Resources, Rhinelander, WI, United States of America.
Department of Forest and Wildlife Ecology, Northland College, Ashland, WI, United States of America.
PLoS One. 2024 Jun 12;19(6):e0301487. doi: 10.1371/journal.pone.0301487. eCollection 2024.
Management of wolves is controversial in many jurisdictions where wolves live, which underscores the importance of rigor, transparency, and reproducibility when evaluating outcomes of management actions. Treves and Louchouarn 2022 (hereafter TL) predicted outcomes for various fall 2021 hunting scenarios following Wisconsin's judicially mandated hunting and trapping season in spring 2021, and concluded that even a zero harvest scenario could result in the wolf population declining below the population goal of 350 wolves specified in the 1999 Wisconsin wolf management plan. TL further concluded that with a fall harvest of > 16 wolves there was a "better than average possibility" that the wolf population size would decline below that 350-wolf threshold. We show that these conclusions are incorrect and that they resulted from mathematical errors and selected parameterizations that were consistently biased in the direction that maximized mortality and minimized reproduction (i.e., positively biased adult mortality, negatively biased pup survival, further halving pup survival to November, negatively biased number of breeding packs, and counting harvested wolves twice among the dead). These errors systematically exaggerated declines in predicted population size and resulted in erroneous conclusions that were not based on the best available or unbiased science. Corrected mathematical calculations and more rigorous parameterization resulted in predicted outcomes for the zero harvest scenario that more closely coincided with the empirical population estimates in 2022 following a judicially prevented fall hunt in 2021. Only in scenarios with simulated harvest of 300 or more wolves did probability of crossing the 350-wolf population threshold exceed zero. TL suggested that proponents of some policy positions bear a greater burden of proof than proponents of other positions to show that "their estimates are accurate, precise, and reproducible". In their analysis, TL failed to meet this standard that they demanded of others.
在许多有狼群生活的司法管辖区,对狼的管理存在争议,这突显了在评估管理行动的结果时,严谨性、透明度和可重复性的重要性。Treves 和 Louchouarn 2022(以下简称 TL)预测了 2021 年春季威斯康星州依法强制狩猎和诱捕季节后,2021 年秋季各种狩猎情景的结果,并得出结论,即使零收获情景也可能导致狼群数量下降到 1999 年威斯康星州狼管理计划规定的 350 只狼的目标以下。TL 进一步得出结论,如果秋季收获超过 16 只狼,那么“很有可能”狼的数量会下降到低于 350 只的阈值。我们表明,这些结论是不正确的,它们是由于数学错误和选择性参数化造成的,这些错误始终偏向于最大限度地增加死亡率和最小化繁殖率(即,偏向于成年死亡率,偏向于幼崽存活率,将幼崽存活率进一步降低到 11 月,偏向于繁殖种群数量,并将被猎杀的狼在死亡数量中重复计算两次)。这些错误系统地夸大了预测种群数量的下降,并导致了基于最佳或无偏见科学的错误结论。经修正的数学计算和更严格的参数化导致零收获情景的预测结果更接近 2021 年秋季因司法阻止而未能进行的狩猎后,2022 年的实际种群估计值。只有在模拟收获 300 只或更多狼的情景下,跨越 350 只狼的种群阈值的概率才超过零。TL 认为,一些政策立场的支持者比其他立场的支持者承担更大的举证责任,以证明“他们的估计是准确、精确和可重复的”。在他们的分析中,TL 未能达到他们对他人的要求标准。