Population density and climate shape early-life survival and recruitment in a long-lived pelagic seabird

• Published in: Journal of Animal Ecology
• Main Authors: Fay, Rémi, Weimerskirch, Henri, Delord, Karine, Barbraud, Christophe
• Other Authors: Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: wandering albatross; population dynamics; capture–mark–recapture; Diomedea exulans; juvenile vital rates; [SDE]Environmental Sciences; Wandering Albatross
• Online Access: https://hal.archives-ouvertes.fr/hal-01304718; https://doi.org/10.1111/1365-2656.12390

International audience 1. Our understanding of demographic processes is mainly based on analyses of traits fromthe adult component of populations. Early-life demographic traits are poorly known mainlyfor methodological reasons. Yet, survival of juvenile and immature individuals is critical forthe recruitment into the population and thus for the whole population dynamic, especially forlong-lived species. This bias currently restrains our ability to fully understand populationdynamics of long-lived species and life-history theory.2. The goal of this study was to estimate the early-life demographic parameters of a longlivedspecies with a long immature period (9–10 years), to test for sex and age effects on theseparameters and to identify the environmental factors encountered during the period of immaturitythat may influence survival and recruitment.3. Using capture–mark–recapture multievent models allowing us to deal with uncertain andunobservable individual states, we analysed a long-term data set of wandering albatrosses toestimate both age- and sex-specific early-life survival and recruitment. We investigated environmentalfactors potentially driving these demographic traits using climatic and fisheries covariatesand tested for density dependence.4. Our study provides for the first time an estimate of annual survival during the first 2 yearsat sea for an albatross species (0801 0014). Both age and sex affected early-life survivaland recruitment processes of this long-lived seabird species. Early-life survival and recruitmentwere highly variable across years although the sensitivity of young birds to environmental variabilitydecreased with age. Early-life survival was negatively associated with sea surface temperature,and recruitment rate was positively related to both Southern Annular Mode and seasurface temperature. We found strong evidence for density-dependent mortality of juveniles.Population size explained 41% of the variation of this parameter over the study period.5. These results indicate that ...