Influence of dispersal processes on the global dynamics of Emperor penguin, a species threatened by climate change

• Published in: Biological Conservation
• Main Authors: Jenouvrier, Stéphanie, Garnier, Jimmy, Patout, Florian, Desvillettes, Laurent
• Other Authors: Woods Hole Oceanographic Institution (WHOI), Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Mathématiques (LAMA), Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS), Unité de Mathématiques Pures et Appliquées (UMPA-ENSL), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS), Institut de Mathématiques de Jussieu - Paris Rive Gauche (IMJ-PRG), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: Habitat selection; Conspecific attraction; Density dependence; Distance of dispersal; Dispersion rate; Carrying capacity; Emperor penguin Antarctica; [SDE]Environmental Sciences; Antarctic; Antarc*; Antarctica; Sea ice
• Online Access: https://hal.science/hal-01573954; https://doi.org/10.1016/j.biocon.2017.05.017

International audience Species endangered by rapid climate change may persist by tracking their optimal habitat; this depends on theirdispersal characteristics. The Emperor penguin (EP) is an Antarctic seabird threatened by future sea ice change,currently under consideration for listing under the US Endangered Species Act. Indeed, a climate-dependentdemographicmodel without dispersion projects that many EP colonies will decline by more than 50% from theircurrent size by 2100, resulting in a dramatic global population decline. Here we assess whether or not dispersioncould act as an ecological rescue, i.e. reverse the anticipated global population decline projected by a modelwithout dispersion. To do so, we integrate detailed dispersal processes in a metapopulation model—specifically,dispersal stages, dispersal distance, habitat structure, informed dispersal behaviors, and density-dependentdispersion rates. For EP, relative to a scenario without dispersion, dispersal can either offset or accelerate climatedriven population declines; dispersal may increase the global population by up to 31% or decrease it by 65%,depending on the rate of emigration and distance individuals disperse. By developing simpler theoretical models,we demonstrate that the global population dynamic depends on the global landscape quality. In addition, theinteraction among dispersal processes - dispersion rates, dispersal distance, and dispersal decisions - that influencelandscape occupancy, impacts the global population dynamics. Our analyses bound the impact of between-colony emigration on global population size, and provide intuition as to the direction of populationchange depending on the EP dispersal characteristics. Our general model is flexible such that multiple dispersalscenarios could be implemented for a wide range of species to improve our understanding and predictions ofspecies persistence under future global change.