Influences of climatic variability, prey abundance, density-dependence, and individual heterogeneity in long-lived top predators : from individual to population

• Main Author: Pacoureau, Nathan
• Other Authors: Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Université de La Rochelle, Christophe Barbraud
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2018
• Subjects: Food availability; Density dependence; Climate; Diet; Individual quality; Life history traits; Bet-hedging strategy; Environmental variability; Bayesian modeling; Capture-mark-recapture; Matrix model; Régime alimentaire; Disponibilité en nourriture; Modélisation bayésienne; Capture-marquage-recapture; Modèle matriciel; Traits d’histoire de vie; Stratégie de bet-hedging; Variabilité environnementale; Qualité individuelle; Densité-dépendance; Climat; [SDV.EE]Life Sciences [q-bio]/Ecology; environment; Antarctic; The Antarctic; Kerguelen; Kerguelen Islands; Pointe-Géologie; Antarc*; Antarctica; Aptenodytes forsteri; Brown Skua; Catharacta maccormicki; Pygoscelis adeliae
• Online Access: https://theses.hal.science/tel-02125078; https://theses.hal.science/tel-02125078/document; https://theses.hal.science/tel-02125078/file/Pacoureau120815.pdf

A fundamental endeavor in population ecology is to identify the drivers of population dynamics. The main objective of this thesis is to determine what are the demographic and population responses of superior marine predators to the fluctuations of their prey abundance, to climatic variations, to density-dependence while taking into account inter and intra individual heterogeneity (age, experience, sex, quality or strategy). To do this, we analysed long-term individual and population-based monitoring of long-lived seabirds and phylogenetically close apical predators in two contrasting biomes: the south polar skua Catharacta maccormicki at Pointe Géologie archipelago, Antarctica, and the brown skua Catharacta lonnbergi on the sub-Antarctic Kerguelen Archipelago. We will use direct abundance of their respective prey: Adélie penguin Pygoscelis adeliae and emperor penguin Aptenodytes forsteri in Antarctica, and the blue petrel Halobaena caerulea and the thin-billed prion Pachyptila belcheri prion in Kerguelen islands. These datasets provide a unique opportunity to simultaneously disentangle and quantify the different sources of variability driving variation in natural populations occupying one of the highest trophic levels of the Antarctic and sub-Antarctic food webs. We found variation in several vital traits of both populations influenced by individual performance and latent individual heterogeneity. We discuss the mechanisms by which climatic variability, prey abundance, and population density can differentially affect the different age classes of each age class, and the potential consequences of future environmental changes. Une question fondamentale en écologie des populations est l’identification des facteurs influençant la dynamique d’une population. L’objectif principal de cette thèse est de déterminer quelles sont les réponses démographiques et populationnelles de prédateurs marins supérieurs face aux fluctuations d’abondance de leurs proies, aux variations climatiques, à la densité-dépendance tout en ...