Impact of climate changes and seabird spatial distribution

• Main Author: Péron, Clara
• 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, Weimerskirch Henri([e-mail])
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2011
• Subjects: seabirds; Austral ocean; foraging strategy; habitat modelling; global warming; future climate scenario; IPCC; oiseaux marins; océan Austral; distribution; stratégie alimentaire; modèle d'habitat; réchauffement; scénario climatique futur; GIEC; adaptation; [SDE]Environmental Sciences; Austral; Kerguelen; Austral Ocean; King Penguins; Sea ice
• Online Access: https://theses.hal.science/tel-00660322; https://theses.hal.science/tel-00660322/document; https://theses.hal.science/tel-00660322/file/PERON_Clara.pdf

According to the Intergovernmental Panel on Climate Change (IPCC), accelerated global warming is now non-equivocal. The aim of this PhD thesis was to assess past and recent climate changes in the Austral ocean and evaluate whether impact of these changes on seabirds spatial distribution was already discernible and/or predictible. Using historical vessel-based surveys data on 12 seabirds species, we documented a decrease in abundance of three species and found distinct changes in distribution between the 1980s and the 2000s. The distributional range of these species extended into subtropical waters where warming has been more pronounced. Tracking data provide crucial information on spatio-temporal variability of foraging habitats. We developped habitat models to (1) caracterize oceanographic conditions of foraging habitats, (2) understand species responses to seasonal and interannual climate variations, and finally (3) predict the future distribution of favourable habitats using IPCC's climatic projections. The two species investigated target productive zones where resources availability is predictable in space and time. Seasonal variations of the distribution of white-chinned petrels (Procellaria aequinoctialis) from Kerguelen are mainly driven by sea-ice dynamic whereas king penguins (Aptenodytes Patagonicus) from Crozet are tightly associated with the polar front. These oceanographic features, forced by temperature, drive the abundance and distribution of marine resources available to predators. Consequently, the 1 to 3°C warming predicted by the IPCC could have major consequences on prey availability in the future. Our predictive models revealed a southward shift of 300 km of king penguin's foraging zones by the end of the 21st century. Such a shift is likely to be beyond penguins' foraging abilities. Despite the uncertainties of models and responses of the lower trophic levels, our results suggest a strong selection pressure on foraging strategies in the future. D'après le dernier rapport du Groupe ...