Responses of Arctic marine birds to winter environmental constraints in the context of climate change

• Main Author: Fort, Jérôme
• Other Authors: Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Université Paul-Valéry - Montpellier 3 (UPVM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut de Recherche pour le Développement (IRD France-Sud ), Université Montpellier II, David Grémillet
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2009
• Subjects: Bioenergetics; Ecophysiological plasticity; Feeding ecology; North Atlantic ecosystem; Seabirds; Winter survival; Bioenergetique; Ecologie alimentaire • • •; Ecosystème Nord Atlantique; Oiseaux marins; Plasticité écophysiologique; Survie hivernale; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.MCG]Environmental Sciences/Global Changes; Arctic; Climate change; North Atlantic
• Online Access: https://hal.archives-ouvertes.fr/tel-01098578; https://hal.archives-ouvertes.fr/tel-01098578/document; https://hal.archives-ouvertes.fr/tel-01098578/file/These_J%20Fort_final.pdf

Harsh environmental conditions encountered in North Atlantic during wintertime, characterized by frequent extreme weather events, are among the most challenging constraints for endothermic animals.Seabirds, which experience this environment for many months per year, play a central role in North Atlantic food webs, notably as top predators and indicators of marine ecosystems. In the current context of climate change, pronounced in North Atlantic waters, it is therefore a major objective tounderstand how seabirds respond and adapt to these environmental constraints shaping their survival and their population dynamics.We used a multidisciplinary approach (combining microelectronics, stable isotopic analyses, bioenergetics modelling and demography) focused on individual energy balance, to study the ecophysiological plasticity of the 3 main alcid species of the North Atlantic.We found that harsh winter conditions induce an energetic bottleneck for seabirds which might explain recurrent events of winter mass mortality, so called ‘seabird winter wrecks’. In response to increased energy expenditure, we showed that seabirds can adopt different strategies allowing higher energy intake. They can modulate their vertical (diving behaviour) and/or horizontal (migration) movements, as well as their trophic status, depending on the spatial and temporal availability of their prey.All together, these results constitute one of the first comprehensive studies of seabird winter ecology. These insights are essential to a better understanding of their population dynamics and constitute a firm foundation to future investigations of the impact of climate change on marine top predators. L’Atlantique Nord en hiver est un environnement rude soumis à des évènements climatiques extrêmes il fait partie des milieux les plus défavorables aux endothermes. Parmi eux, les oiseaux marins jouent un rôle majeur en temps que prédateurs supérieurs et bioindicateurs des écosystèmespélagiques. Dans le contexte actuel de changements globaux très ...