- Details
- Written by Clyde McMillan-Gamber Clyde McMillan-Gamber
The 4-foot-tall, 88-pound emperor penguins are the only birds on Earth that raise young on sea ice around the Antarctic Continent during the southern hemisphere’s winter, which is our summer.
However, these stately penguins that stand upright are built for bitterly cold, windy conditions. They have two layers of dense feathering and are lined with fat.
Though penguins of all species can’t fly, their long, powerful wings are used for diving and swimming in the oceans to procure food. And emperors are known to stay submerged up to 20 minutes.
Emperor penguins begin their breeding season in April (during the southern autumn) when they leave the Antarctic Ocean.
Each bird finds its mate in noisy throngs of tens of thousands of individuals on the sea ice around the Antarctic continent. Each pair courts with much bowing and posturing and then finally mates.
Later, each female lays a single egg and, having no nest materials, gives the egg to her mate, who pushes it on his feet with his beak and plops a feathered brood pouch on that egg to keep it warm.
Female emperors leave the nesting colonies early in June (midwinter) to gorge on krill, squid, and small fish in the Antarctic Ocean. Meanwhile, their mates, by the thousands, stand together in tightly massed huddles to stay warm and incubate their eggs.
There the males stand, clustered together, for two months, without eating or drinking and in bitter winds, blizzards of ice and snow, and the total darkness of the southern winter, each patient father incubating a single embryo.
Female emperors return to the nesting colonies late in July (still winter). Each mother is fat and has a stomach full of half-digested krill, fish, and squid, much of which she will feed to her chick, who hatched in mid-August. Each mother takes her chick on her feet and feeds it frequently. Finally, all the males trudge to the ocean to get food.
During October and November (spring in the southern hemisphere), each pair of emperors takes turns feeding themselves in the ocean and feeding and protecting their chick from giant petrels and south polar skuas, a gull relative.
As the chicks grow, they develop their own masses to stay warm and fight off those predatory birds themselves. That independence allows both parents freedom to hunt food in the ocean and shuttle some of it to their youngster.
Adult emperors leave nesting colonies in December and feed in the ocean until April. The chicks fledge in December by diving off ice floes into the ocean to feed themselves. Young and adult penguins must be alert for the large leopard seals that prowl along the sea ice to catch and eat some of those birds.
Emperor penguins start their breeding season in the southern hemisphere’s fall and through its winter so their chicks can be independent in the southern summer, when there are 24 hours of sunlight, warmer weather, and melted sea ice — and the living around the Antarctic continent is as easy as it will get.
Clyde McMillan-Gamber is a retired Lancaster County Parks naturalist.