Stomach stones in king penguin chicks

• Published in: Polar Biology
• Main Authors: Beaune, David, Le Bohec, Céline, Lucas, Fabrice, Gauthier-Clerc, Michel, Le Maho, Yvon
• Other Authors: Département Ecologie, Physiologie et Ethologie (DEPE-IPHC), Institut Pluridisciplinaire Hubert Curien (IPHC), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences Oslo, Faculty of Mathematics and Natural Sciences Oslo, University of Oslo (UiO)-University of Oslo (UiO)-Faculty of Mathematics and Natural Sciences Oslo, University of Oslo (UiO)-University of Oslo (UiO), Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la Tour du Valat
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2009
• Subjects: Gastrolith; Grit; Seabird; Digestion; Adaptive behaviour; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDV.BID.EVO]Life Sciences [q-bio]/Biodiversity/Populations and Evolution [q-bio.PE]; King Penguins; Polar Biology
• Online Access: https://hal.science/hal-00362821; https://doi.org/10.1007/s00300-008-0558-1

International audience Many animals that possess a gizzard swallow stones or sandy grit, supposedly to aid in the mechanical breakdown of food. While this has been well documented in the literature, our study is the first to report the presence of stones in the gizzard of king penguin chicks. We found stones, so called ‘gastroliths', in the pyloric region of the gizzard, the part of the digestive tract that is specialised for the mechanical breakdown of food. Stones were already present in the gizzard of chicks and, hence, during the first year of the life of king penguins, which is spent on land. Some chicks were found to have more than 130 stones (0.5–22 mm in size) in their gizzard. The gastroliths we found in king penguins are of the same geological origin as rocks present at the colony, which suggests that birds swallowed them there. The functional role of gastroliths in penguin chicks and adults is still unknown. We discuss the potential roles that these gastroliths might play in king penguins (i.e. aid in digestion, buoyancy control during foraging at sea, adaptation to fasting).