Ontogeny of foraging behaviour during the early life of deep diving predators

• Main Author: Orgeret, Florian
• Other Authors: Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Université de La Rochelle, Charles-André Bost, Christophe Guinet
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2018
• Subjects: First year at sea; Learning; Elephant seals; Penguins; Diving behaviour; Navigation; Orientation; Exploration; Migration; Mortality; Manchots; Eléphants de mer du Sud; Juvéniles; Première année en mer; Apprentissage; Comportement de plongée; Mortalité; [SDV.AEN]Life Sciences [q-bio]/Food and Nutrition; Eléphants; Empereurs; Southern Ocean; Antarc*; Antarctique*; Elephant Seals; Emperor penguins; King Penguins; Southern Elephant Seals
• Online Access: https://tel.archives-ouvertes.fr/tel-02157076; https://tel.archives-ouvertes.fr/tel-02157076/document; https://tel.archives-ouvertes.fr/tel-02157076/file/2018Orgeret113333.pdf

The juvenile phase of long lived-species is poorly understood despite its critical importance for the future of animal populations. Thanks to new bio-technologies, in this thesis we managed to monitor the ontogeny of foraging behaviour in 52 juveniles from 3 deep-diving marine predator species (king penguins, emperor penguins and southern elephant seals) in the French Southern territories over the first year after their independence. The juveniles of these 3 species showed a very large dispersion range over huge distances in the Southern Ocean. Their dispersion was characterized at departure by partially innate behaviour in their orientation preferences. Juveniles showed a strong dependency to the local oceanic currents orientation and frontal zones. More, they showed a spatial segregation with adults. Juveniles were quickly able to dive very deep. Their diving and foraging skills increased progressively with time. However, juveniles never completely reached the efficiency of adults, even after one year at sea. Some juveniles did not manage to increase their foraging skills while their environment became less productive; these juveniles may have died at sea, probably because of starvation. The first year at sea appears thus to be critical for the 3 studied species, as substantial mortality occurred in each case. This thesis presents new information about the ontogeny of dispersion and the foraging behaviour in marine deep-diving predators. La période juvénile d’espèces longévives demeure peu connue malgré son importance pour la démographie et la conservation des populations. L’objectif de cette thèse a été d’étudier le comportement de dispersion et de nourrissage de 52 juvéniles de trois espèces de prédateurs marins plongeurs des Terres Australes et Antarctiques Françaises (les manchots royaux, les manchots empereurs et les éléphants de mer du Sud) pendant quasiment 1 an après leur indépendance. L’approche a été basée sur l’utilisation de balises retransmettant en direct la localisation et des données de ...