Relationships between sea ice concentration, sea surface temperature and demographic traits of thin-billed prions
Résumé
Understanding the effects of environmental variations on ecosystems is a major topic in ecology. In this study, we estimated demographic parameters of a seabird population, the thin-billed prion (Pachyptila belcheri) at Kerguelen Islands, and then tested for relationships with inter-annual variations of climatic indices, using long-term capture–recapture data. The annual adult survival probability was 0.825±0.009 and the breeding success was 0.519±0.090. Sea surface temperature anomalies were negatively related with breeding success. By contrast, winter sea ice concentration in the Antarctic seasonal ice zone seemed to negatively influence adult survival. This suggests a connection between sub-Antarctic and Antarctic ecosystems. The actual context of large climatic changes in the Austral Ocean seems to explain a large part of the decreasing trends observed for both the breeding success and the adult survival. Thus, a decrease of the population size of thinbilled prions at Kerguelen could be strongly suspected in the near future.