Goose-beaked whales (Ziphius cavirostris) are deep-diving cetaceans known for their elusive nature and specialized foraging behavior. In 2019 and 2020, six telemetry tags were deployed on these whales in Southern California, resulting in 395 h of acoustic and diving data. Foraging dives were manually identified by the presence of echolocation pulses and buzzes, and generalized additive models assessed factors influencing foraging behavior. The median bathymetric depth at foraging sites was 1,419 m (IQR = 359), and the maximum dive depth was highly correlated with bathymetry depth. Individuals started echolocating on descent at a median depth of 410 m (IQR = 74); pulses were not observed shallower than 292 m. Echolocation ceased during the bottom phase for 81.6% of dives, at a median depth of 1,265 m (IQR = 472); pulses were not observed shallower than 587 m on ascent. The median depth of buzzes was 1,215 m (IQR = 479) with 63% occurring during the bottom phase. Deeper dives correlated with longer durations of diving and echolocation, greater echolocation end depths, and wider bottom phase echolocation depth inter-quartile range. The median difference between dive depth and bottom phase median echolocation depth was 98.3 m (IQR = 48.5), suggesting whales in this region forage in a narrow band close to the seafloor. In the San Nicolas Basin, individuals exhibited longer echolocation durations, produced more pulses, and started and ended echolocating at greater depths compared to adjacent regions. These records validate and expand upon previous studies, providing insights into factors influencing foraging behavior in an area with high anthropogenic disturbance.

中文翻译：

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通过对南加州湾鹅喙鲸（Ziphius cavirostris）的多日录音标签了解觅食行为


鹅喙鲸（Ziphius cavirostris）是深潜鲸类动物，以其难以捉摸的天性和专门的觅食行为而闻名。 2019 年和 2020 年，在南加州的这些鲸鱼上部署了 6 个遥测标签，产生了 395 小时的声学和潜水数据。觅食潜水是通过回声定位脉冲和嗡嗡声的存在来手动识别的，广义相加模型评估了影响觅食行为的因素。觅食地点的中位测深深度为1,419 m（IQR = 359），最大潜水深度与测深深度高度相关。个体在中位深度 410 m 下降时开始回声定位（IQR = 74）；浅于 292 m 时未观察到脉冲。 81.6% 的潜水在水底阶段回声定位停止，中位深度为 1,265 m (IQR = 472)；上升时未观察到低于 587 m 的脉冲。嗡嗡声的中位深度为 1,215 m (IQR = 479)，其中 63% 发生在底部阶段。更深的潜水与更长的潜水和回声定位持续时间、更大的回声定位结束深度以及更宽的底部相位回声定位深度四分位数范围相关。潜水深度和海底相位中值回声定位深度之间的中值差为 98.3 m (IQR = 48.5)，表明该地区的鲸鱼在靠近海底的狭窄带内觅食。在圣尼古拉斯盆地，与邻近区域相比，个体表现出更长的回声定位持续时间，产生更多的脉冲，并在更大的深度开始和结束回声定位。这些记录验证并扩展了之前的研究，提供了对影响人为干扰严重地区觅食行为的因素的见解。