Demography of cape petrels in response to environmental changes

• Published in: Population Ecology
• Main Authors: Sauser, Christophe, Delord, Karine, Barbraud, Christophe
• Other Authors: Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), La Rochelle Université (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 2023
• Subjects: cape petrel; capture–mark–recapture; population dynamics; sea surface temperature; southern annular mode; [SDE]Environmental Sciences; Pointe-Géologie; Terre Adélie; Terre-Adélie; Antarc*; Antarctica; Cape Petrel; Cape Petrels
• Online Access: https://hal.science/hal-03736435; https://doi.org/10.1002/1438-390X.12133

International audience Predicting the responses of populations in changing environments is an importanttask for ecologists. Understanding the population dynamics of highlatitudebreeding species is critical given the particularly rapid environmentalchanges that occur in these regions. Using long-term mark–resighting dataacquired over 53-years in Pointe Géologie, Terre Adélie, Antarctica, we estimatedage-specific demographic parameters and evaluated the effect of theenvironment on survival of a poorly known species, the cape petrel Daptioncapense. We then modeled the dynamics of this population using a life-historymodel and performed prospective and retrospective analyses to estimate thesensitivity of the population growth rate to demographic parameters, and toquantify their relative contribution. Survival of cape petrel increased with age,being 0.610 (±0.193) for juveniles, 0.739 (±0.158) for individuals from 2 to4, and 0.920 (±0.031) for older individuals. Minimum age at first reproductionwas 3 years old, the age at which all birds were recruited was 14 years, andmean age at first reproduction was 9.05 (±2.06) years. Adult survival increasedover time and was positively correlated with the southern annular mode(SAM). The stochastic population growth rate was estimated at 1.019, andadult survival over age 5 made the largest contribution to variance of the populationgrowth rate. Sensitivity analyses revealed that population regulation wasmainly driven by the SAM. Our results suggest that despite the decrease inbreeding success, the population of cape petrels at Pointe Géologie increaseddue to the increase in immature and adult survival.