Breaking the fast: first report of dives and ingestion events in molting southern elephant seals

• Published in: Communications Biology
• Main Authors: Charlanne, Laura, Chaise, Laureline, Sornette, Damien, Piot, Erwan, Mccafferty, Dominic, J, Ancel, André, Gilbert, Caroline
• Other Authors: 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), Mécanismes Adaptatifs et Evolution (MECADEV), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), College of Medical, Veterinary and Life Sciences Glasgow, University of Glasgow, École nationale vétérinaire d'Alfort (ENVA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: Kerguelen Archipelago; molting; Mirounga leonina; ingestion; at-sea movements; [SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology; Kerguelen; Elephant Seals; Southern Elephant Seals
• Online Access: https://hal.science/hal-04381893; https://hal.science/hal-04381893/document; https://hal.science/hal-04381893/file/Breaking%20the%20fast_Manuscript.pdf; https://doi.org/10.1038/s42003-023-05720-2

International audience Southern elephant seals (SES) experience a ‘catastrophic molt’, a costly event characterized by the renewal of both hair and epidermis that requires high peripheral vascular circulation. Molting animals are therefore constrained by high metabolic heat loss and are thought to fast and remain on land. To examine the ability of individuals to balance the energetic constraints of molting on land we investigate the stomach temperature and movement patterns of molting female SES. We find that 79% of females swam and 61% ingested water or prey items, despite the cost of cold-water exposure while molting. This behavior was related to periods of warm and low wind conditions, and females that dived and ingested more often, lost less body mass. We conclude that the paradigm of fasting during the molt in this species, and the fitness consequences of this behavior should be reconsidered, especially in the context of a changing climate.