Division of Polar Life Sciences, Korea Polar Research Institute, Incheon, Republic of Korea.
School of Biological Sciences, University of Nebraska, Lincoln, United States of America.
Sci Rep. 2017 Aug 17;7(1):7570. doi: 10.1038/s41598-017-07900-7.
In contrast to their terrestrial call, the offshore call of penguins during their foraging trips has been poorly studied due to the inaccessibility of the foraging site-the open ocean-to researchers. Here, we present the first description of the vocal behaviour of penguins in the open ocean and discuss the function of their vocal communication. We deployed an animal-borne camera on gentoo penguins (Pygoscelis papua) and recorded their foraging behaviour during chick guarding. From the video recordings, we collected 598 offshore calls from 10 individuals in two breeding seasons (2014-2015 and 2015-2016), and we analysed the acoustic characteristics and behavioural contexts of these calls, including diving patterns, group association events, and foraging behaviour. The offshore calls varied in their dominant frequency and length, and penguins produced calls of different lengths in succession. Group associations were observed within one minute following an offshore call in almost half of the instances (43.18%). Penguins undertook dives of shallower depths and shorter durations after producing an offshore call than those before producing an offshore call. Our findings show that penguins may use vocal communication in the ocean related with group association during foraging trips.
与它们在陆地上的叫声相比，由于觅食地点——开阔海域——对研究人员来说难以到达，因此对企鹅在觅食过程中的离岸叫声的研究甚少。在这里，我们首次描述了开阔海域中企鹅的发声行为，并讨论了它们的声音通讯功能。我们在 10 只巴布亚企鹅（Pygoscelis papua）身上安置了一个动物携带的摄像机，并记录了它们在孵育期间的觅食行为。从视频记录中，我们在两个繁殖季节（2014-2015 年和 2015-2016 年）收集了 10 只个体的 598 次离岸叫声，并分析了这些叫声的声学特征和行为背景，包括潜水模式、群体关联事件和觅食行为。离岸叫声的主频和长度各不相同，企鹅会连续发出不同长度的叫声。在几乎一半的情况下（43.18%），离岸叫声后不到一分钟就会出现群体关联。企鹅在发出离岸叫声后，潜水深度较浅，持续时间较短。我们的研究结果表明，企鹅在觅食过程中可能会利用与群体关联有关的声音通讯。
