Emperor penguin colonies in Antarctica are expected to be in decline by 2100, with two-thirds of colonies projected to shrink to less than half of their present population. These findings, reported this week in Nature Climate Change, are based on projected changes in Antarctic sea-ice concentration under climate change.
The success of emperor penguin (Aptenodytes forsteri) colonies is intimately linked to sea-ice concentrations. Too little ice affects food availability as it negatively impacts marine food webs, whereas too much forces adults to travel further to forage for food to bring back to their chicks.
Stephanie Jenouvrier and colleagues modelled population trends for the 45 known emperor penguin colonies, taking account of sea-ice conditions projected by a range of climate models. They found that although year-to-year colony population growth rates are mostly positive until 2040, all colonies will begin to experience negative growth by 2080.