Beaked whales produce frequency-modulated echolocation pulses that appear to be species-specific, allowing passive acoustic monitoring to play a role in understanding spatio-temporal patterns. The Cross Seamount beaked whale is known only from its unique echolocation signal (BWC) with no confirmed species identification. This beaked whale spans the Pacific Ocean from the Mariana Archipelago to Baja California, Mexico, south to the equator, but only as far north as latitude 29°N. Within these warm waters, 92% of BWC detections occurred at night, 6% during crepuscular periods, and only 2% during daylight hours. Detections of BWC signals on drifting recorders with a vertical hydrophone array at 150 m depth demonstrated that foraging often occurred shallow in the water column (<150 m). No other species of beaked whale to date has been documented foraging in waters this shallow. Given their nocturnal, shallow foraging dives, this species appears to prefer prey that may be available in the water column only during those hours. The foraging behavior of Cross Seamount beaked whales appears to be unique among all beaked whales, and these findings contribute additional ecological and acoustic information which can help guide future efforts to identify this cryptic whale.

中文翻译：

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基于声学探测的跨海山喙鲸地理分布

喙鲸产生似乎是物种特异性的调频回声定位脉冲，使得被动声学监测在理解时空模式方面发挥作用。跨海山喙鲸只能通过其独特的回声定位信号（BW​​C）来了解，没有经过确认的物种鉴定。这种喙鲸横跨太平洋，从马里亚纳群岛到墨西哥下加利福尼亚州，南至赤道，北至北纬 29°。在这些温暖的水域中，92% 的 BWC 检测发生在夜间，6% 发生在黄昏期间，只有 2% 发生在白天。用垂直水听器阵列在 150 m 深度的漂流记录仪上检测到的 BWC 信号表明，觅食通常发生在水体浅层（<150 m）。迄今为止，还没有其他种类的喙鲸在如此浅的水域中觅食的记录。鉴于它们在夜间进行浅层觅食潜水，该物种似乎更喜欢仅在这些时间内才能在水柱中找到的猎物。跨海山喙鲸的觅食行为在所有喙鲸中似乎是独一无二的，这些发现提供了额外的生态和声学信息，有助于指导未来识别这种神秘鲸鱼的工作。