Seabirds response to climate change in the Southern Ocean

Péron C (1), Jenouvrier S (2), Bost C.A (3), Weimerskirch H (3)

1 Institute for Marine and Antarctic Studies, University of Tasmania and Australian Antarctic Division, 203 Channel Highway,

Kingston, Tasmania 7050 Australia,

2 Biology Department MS-50, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543 USA,

3 Centre d’Etudes Biologiques de Chizé UMR 7372 CNRS/Univ La Rochelle, 79360 Villiers en Bois, France,,

The Southern Ocean is a highly dynamic system, home to a large diversity of species. Weather, climate, ice extent, and ocean currents are undergoing unprecedented levels of change with consequences for the entire food-web. As top predators, seabirds have been responding to these changes over the last few decades and projected warming is expected to cause dramatic changes in their populations over the next century. Using long-term satellite-tracking datasets of different seabird species, we were able to detect changes in seabird foraging ranges and link them to changes in key climate and oceanographic parameters such as wind, fronts or sea-ice extent. Whereas the endless glider wandering albatross takes advantage of stronger winds to travel faster in search of scattered prey, the active diver king penguin compromises its fitness when trying to keep up with the southward shift of the polar front where its favourite prey is concentrated. Projections derived from general circulation models forced by 3 IPCC scenarios indicate that profitable foraging zones of king penguins breeding on Crozet Islands will be out of reach by the end of the century. Consequences on demographic rates are expected to be drastic and could lead to local population extinctions. Using a stage-structured demographic model on a 30-year longitudinal individual based dataset, we found that an increase in frequency of extreme sea-ice conditions in Antarctica could strongly impact the persistence of ice-associated species, such as the southern fulmar, and act as an important agent in the natural selection of life history traits.