Oil and gas activities on Alaska's North Slope overlap spatially with polar bear (Ursus maritimus) maternal denning habitat and temporally with the peri‐partum and emergence periods. Noise associated with these activities can be substantial and concerns regarding the effects on polar bears have been acknowledged. But the secluded and ephemeral nature of subnivean maternal dens renders the measurement of behavioral and physiological responses of bears to noise exposure challenging, except for rare cases when disturbance‐prompted den abandonment has been documented. These limitations, coupled with the uncertainty associated with the synergistic effects of anthropogenic activities on bears in a rapidly changing Arctic, prompt the need to develop predictive models of disturbance to ensure management guidelines effectively mitigate disturbance. Towards this end, we characterized noise propagation from 9 sources (2 aircraft, 2 over‐tundra tracked vehicles, 4 wheeled on‐road vehicles, and humans walking) used to support industrial activities around artificial snow dens near Milne Point, Alaska, USA, in March–April 2010. We built dens in 4 configurations to mimic variability in den roof thickness and to evaluate differences in noise propagation from when the den was closed compared to being open, similar to den emergence. We integrated these data with an existing polar bear audiogram and developed models to predict auditory‐detection probabilities as a function of distance from the den. Within a closed den, aircraft had high probabilities (detection probability ≥75%) of being detected by polar bears at distances ≤1.6 km and ground‐based sources had high probabilities of detection at distances ≤0.8 km. On average, closed dens reduced noise levels by 15 decibels (dB) relative to open dens. Our findings indicate that although polar bear snow dens effectively attenuate acoustic sound pressure levels, noise from some industrial support vehicles was likely to be detected farther from dens than previously documented. These results reinforce the importance of maintaining buffer zones around polar bear dens to minimize the potential for den disturbance. © 2020 The Wildlife Society.

中文翻译：

---

估算工业噪声对北极熊的可听性

阿拉斯加北坡的油气活动在空间上与北极熊（Ursus maritimus）产妇的栖息地以及在时间上与围产期和出苗期有关。与这些活动相关的噪音可能很大，并且人们已经意识到对北极熊的影响。但是，亚庇亚文产妇窝的隐蔽性和短暂性使得测量熊对噪声暴露的行为和生理反应具有挑战性，除非有极少数情况证明有扰乱提示的窝被遗弃。这些局限性，再加上人为活动对北极迅速变化的北极熊的协同效应所产生的不确定性，促使人们需要建立干扰的预测模型，以确保管理准则能有效减轻干扰。为此，我们对9个来源（2架飞机，2010年3月至4月，用于支持在美国阿拉斯加米尔恩角附近的人造雪窝周围进行工业活动的2辆超苔原履带车辆，4轮公路车辆和人类行走车。我们模拟了变异性，以4种配置建造了巢穴在书房屋顶厚度方面进行评估，并评估书房关闭与打开时书房关闭时噪声传播的差异，类似于书房出现。我们将这些数据与现有的北极熊听力图进行了集成，并开发了模型来预测听觉检测概率作为与巢穴距离的函数。在一个封闭的巢穴内，飞机在≤1.6km的距离内被北极熊发现的概率很高（检测概率≥75％），在距离≤0.8km的地面上，源具有很高的检测概率。一般，相对于开放式窝点，封闭式窝点将噪声水平降低了15分贝（dB）。我们的发现表明，尽管北极熊雪坑可以有效地减弱声压级，但是与以前记录的相比，从工业坑道发现的一些工业支撑车辆的噪声很可能会被发现。这些结果加强了在北极熊巢穴周围保持缓冲区以最小化巢穴干扰的可能性的重要性。©2020野生动物协会。