Vast fields of barren ice may seem like a poor choice of living quarters, but that’s where Adelie Penguins prosper. They spend much of the year on floating pack ice just north of the Antarctic Circle, where in some months they have barely enough daylight to fish. They’re so well insulated that they pant when temperatures rise above freezing.
As winter sets in, wind and waves push new-forming ice into floes that get mashed against the shoreline. The fractured ice surface contains shifting stretches of open water called leads. Adelies dive through the leads to access the rich supply of krill, squid, and fish underneath.
As the seasonal ice pack grows, nearly doubling the size of Antarctica, Adelies keep close to the expanding coastline so they won’t be stranded far from open water as leads close up. Migrating minke whales break breathing holes from beneath, which swimming Adelies can use as inverted stepping stones to open water.
As the ice retreats in spring, Adelies migrate inland to nest in colonies during the brief Antarctic summer. Whether coming or going with the fluctuating ice, Adelie Penguins have mastered survival in the harshest climate on earth.