Castellote Manuel, Mooney T Aran, Quakenbush Lori, Hobbs Roderick, Goertz Caroline, Gaglione Eric
National Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, Seattle, WA 98115, USA North Gulf Oceanic Society, Homer, AK 99603, USA.
Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
J Exp Biol. 2014 May 15;217(Pt 10):1682-91. doi: 10.1242/jeb.093252.
While hearing is the primary sensory modality for odontocetes, there are few data addressing variation within a natural population. This work describes the hearing ranges (4-150 kHz) and sensitivities of seven apparently healthy, wild beluga whales (Delphinapterus leucas) during a population health assessment project that captured and released belugas in Bristol Bay, Alaska. The baseline hearing abilities and subsequent variations were addressed. Hearing was measured using auditory evoked potentials (AEPs). All audiograms showed a typical cetacean U-shape; substantial variation (>30 dB) was found between most and least sensitive thresholds. All animals heard well, up to at least 128 kHz. Two heard up to 150 kHz. Lowest auditory thresholds (35-45 dB) were identified in the range 45-80 kHz. Greatest differences in hearing abilities occurred at both the high end of the auditory range and at frequencies of maximum sensitivity. In general, wild beluga hearing was quite sensitive. Hearing abilities were similar to those of belugas measured in zoological settings, reinforcing the comparative importance of both settings. The relative degree of variability across the wild belugas suggests that audiograms from multiple individuals are needed to properly describe the maximum sensitivity and population variance for odontocetes. Hearing measures were easily incorporated into field-based settings. This detailed examination of hearing abilities in wild Bristol Bay belugas provides a basis for a better understanding of the potential impact of anthropogenic noise on a noise-sensitive species. Such information may help design noise-limiting mitigation measures that could be applied to areas heavily influenced and inhabited by endangered belugas.
虽然听觉是齿鲸的主要感觉方式，但针对自然种群内的差异的数据却很少。这项研究描述了在阿拉斯加布里斯托尔湾进行的一项种群健康评估项目中，7头看似健康的野生白鲸（白鲸属）的听力范围（4-150千赫）和敏感度，该项目捕捉并放生了白鲸。研究探讨了基线听力能力及随后的差异。使用听觉诱发电位（AEP）测量听力。所有听力图均呈现典型的鲸类U形；在最敏感阈值和最不敏感阈值之间发现了显著差异（>30分贝）。所有动物的听力都很好，至少能听到128千赫。有两头能听到150千赫。最低听觉阈值（35-45分贝）出现在45-80千赫范围内。听力能力的最大差异出现在听觉范围的高端和最大敏感度频率处。总体而言，野生白鲸的听力相当敏感。其听力能力与在动物园环境中测量的白鲸相似，这凸显了两种环境的比较重要性。野生白鲸之间的相对变异程度表明，需要多个个体的听力图才能恰当地描述齿鲸的最大敏感度和种群差异。听力测量很容易融入基于野外的环境中。对布里斯托尔湾野生白鲸听力能力的详细研究为更好地理解人为噪声对这种对噪声敏感的物种的潜在影响提供了基础。此类信息可能有助于设计可应用于受濒危白鲸严重影响和栖息地区的噪声限制缓解措施。
