Movements and habitat selection in animals outside the breeding period: at-sea ecology of penguins during inter-breeding and immaturity periods

• Main Author: Thiebot, Jean-Baptiste
• Other Authors: Centre d'Études Biologiques de Chizé (CEBC), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris VI, BOST Charles-André([e-mail])
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2011
• Subjects: winter; post-natal dispersion; marine resources; ecological niche; Southern Ocean; marine predators; penguins; telemetry; light-based geolocation; stable isotopes; migration; hiver; dispersion post-natale; ressources marines; ségrégation; niche écologique; conservation; Océan Austral; prédateurs marins; manchots; télémétrie; géo-localisation par la lumière; isotopes stables; Eudyptes chrysolophus; Eudyptes filholi; Eudyptes moseleyi; Pygoscelis papua; Aptenodytes forsteri; [SDE]Environmental Sciences
• Online Access: https://theses.hal.science/tel-00660333; https://theses.hal.science/tel-00660333/document; https://theses.hal.science/tel-00660333/file/Thiebot_JB.pdf

Animal movements in their environment reveal the resources they depend on in this environment. Levels of human impact in the marine environment (mainly through fisheries) have broken ecological balance, this being obvious at higher trophic levels. Our work therefore aimed at depicting movements of locally to globally declining marine predators. We especially focused on movements outside the breeding period, when predators generally face heavy constraints for survival while at-sea for a prolonged period, in 5 penguin species being keystones as consumers in a gradient of environments in the southern Indian Ocean. Their movements were investigated using light-based geolocation or satellite telemetry, and their trophic ecology by carbon and nitrogen stable isotope analyses. Our work allowed to delineate and to characterize the oceanic sectors exploited during the whole inter-breeding period by 3 congeneric species of penguins (genus Eudyptes). Then, inter-site, inter-species and inter-annual comparisons highlighted population-based striking mechanisms of ecological segregation in space, time and on food. Finally, our studies on post-natal dispersion in 2 other penguin species revealed the prospection of a contrasted habitat compared to the adults situation, and the probable action of innate skills. Our studies appear crucial in the conservation of the studied species in the study area, and rise questions about the dynamics of the population-based movement patterns observed, considering competition pressures and mobility of the targeted habitats. Les déplacements entrepris par les animaux dans leur milieu reflètent les ressources conditionnant leur survie dans ce milieu. En milieu marin, l'intensité des activités humaines (notamment la pêche) a entraîné des bouleversements écologiques, particulièrement aux échelons trophiques supérieurs. Cette thèse a donc visé à documenter les déplacements de prédateurs marins dont les effectifs baissent à un niveau local ou global. Nous avons étudié les déplacements en dehors de ...