Seabird range contraction and dispersal under climate change

Abstract Many marine ectotherms have responded to local warming through body-size reductions and dispersal to optimal environments. However, whether endothermic marine species, such as seabirds, exhibit similar responses remains unclear owing to gaps in literature that hinder comprehensive global assessments. Here we show that globally distributed seabirds (albatrosses, petrels, shearwaters and storm petrels) facing rapid historical climate change responded with changes in geographic range size rather than body mass. In addition, under higher rates of climate change, species’ ranges contracted most, forcing these species to disperse longer distances. These historical inferences align with expected responses to modern climate change, as over 70% of extant species contract their ranges and disperse farther under a climate scenario leading to severe warming by 2100. These results underscore the urgent need to integrate range dynamics into conservation strategies and reveal that the rate of climate change poses the greatest threat to seabird diversity.