As climate change raises seawater temperatures, king penguin populations could shrink, say researchers. Since 1999, implanted ID tags like those for dogs have let researchers monitor bird family life on the Crozet Archipelago in the Indian Ocean. Warmer water means less food. Chick survival declined during seasons with higher surface water temperatures, reports Yvon Le Maho of CNRS in Strasbourg, France.
In winter, adult king penguins leave chicks to fast for months while parents swim away to replenish their strength in food-rich waters near Antarctic ice. The team found that adult populations eventually declined after winters with unseasonably warm waters. A 0.26°C warming of seawater can reduce adult survival 9 percent, the researchers report in the Feb. 19 Proceedings of the National Academy of Sciences.