Antarctica’s iconic emperor penguin has been deemed an endangered species as the sea ice it depends on shrinks because of rising temperatures. The penguins’ population is expected to drop by half by ...

Researchers scanning satellite images of West Antarctica stumbled onto clusters of emperor penguins gathered on fast ice to molt, a seasonal process in which the birds shed and regrow their feathers.

Each year for millennia, emperor penguins have molted on coastal sea ice that remained stable until late summer—a haven during a span of several weeks when it’s dangerous for the mostly aquatic birds ...