Emperor Penguin (Aptenodytes forsteri)

node · earth · Antarctic coast - circumpolar

The only bird that breeds through the Antarctic winter, and the only vertebrate that does its reproduction on sea ice rather than land. The pair lays a single egg in the early winter dark; the female returns to the sea to feed and the male incubates it on his feet under a fold of skin for about two months, fasting throughout and huddling in a slowly rotating mass with thousands of others against wind chill that no other bird survives. The strategy only works because the chick then fledges in the spring, when food is at its most abundant - which requires the landfast ice under the colony to hold from laying until fledging. Most known colonies were found by satellite rather than by ship, from the stain their guano leaves on the ice, and the count of known colonies has risen with image resolution rather than with population.