Stay the course: maintenance of consistent orientation by commuting penguins both underwater and at the water surface

• Published in: Marine Biology
• Main Authors: Shiomi, Kozue, Sato, Katsufumi, Bost, Charles, A, Handrich, Yves
• Other Authors: FRIS - Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University Sendai, Atmosphere and Ocean Research Institute Kashiwa-shi (AORI), The University of Tokyo (UTokyo), Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: Bearing Compass Diving bird Navigation Orientation; Bearing; Compass; Diving bird; Navigation; Orientation; [SDE]Environmental Sciences; Antarctic; The Antarctic; Possession Island; Antarc*; King Penguins
• Online Access: https://hal.science/hal-04030281; https://doi.org/10.1007/s00227-023-04186-4

International audience Many marine vertebrates traverse more than hundreds of kilometres of the ocean. To efficiently achieve such long-distance movements, the ability to maintain orientation in a three-dimensional space is essential; however, it remains unevaluated in most species. In this study, we examined the bearing distributions of penguins undertaking long-distance foraging trips and compared their bearing consistency between underwater and at the water surface, as well as between night and day, to quantify their orientation ability. The subject species, king penguins, Aptenodytes patagonicus, from Possession Island, Crozet archipelago (46°25′S, 51°45′E; January to March 2011), showed high bearing consistency both during dives and at the water surface whilst commuting towards/from their main foraging area, the Antarctic polar front. Their bearing consistency was particularly high during and after shallow dives, irrespective of the time of day. Meanwhile, their bearings tended to vary during and after deep dives, particularly in the middle of the trip, probably owing to underwater foraging movements. However, the overall directions of deep dives during the commuting phases were similar to those of shallow dives and post-dive periods at the water surface. These findings indicate that king penguins employ compass mechanism(s) that are equivalently reliable both underwater and at the water surface, at any time of the day. This orientation ability appears to enable them to achieve long-distance trips under strong temporal constraints. Further studies on the fine-scale bearing distributions of other diving vertebrates are needed to better understand movement strategies in marine environments.