Many birds display remarkably unselfish traits during parenthood. Because their offspring begin as eggs, bird parents must prepare a place to store eggs safely, they must keep the eggs at an even temperature, they must take food to the newly hatched infants (no supply of ready—made formula comes with them as with newborn mammals), and they are often expected to teach the fledglings the rudiments of flight.

But of all the sacrificing birds, none is more indulgent, tolerant, imperturbable, or faithful than the emperor penguin. These remarkable birds that live in temperatures averaging —80 degrees Fahrenheit, amid blizzards with normal wind velocities of ninety miles per hour, in the darkness of the long winter night within the Antarctic Circle, are among the most self—sacrificing creatures imaginable.

While other migratory birds move to warmer climates before winter, emperor penguins seek the most inhospitable region of the earth during its coldest, darkest, most hostile season of the year to mate, brood, and raise their young. On ice floes, usually near the same locale they visited the previous year, they assemble in great flocks in about March, just as winter begins. Males and females arrive separately after a trip of several thousand miles from any of the oceans of the Southern Hemisphere.

Upon arrival each male begins his courtship song. It is by this song, amid the cacophony of a thousand other mating melodies, that the female, most frequently his wife of the previous season, recognizes him. In about two months, during which time the birds have been fasting, an egg is laid. It is immediately transferred from the mother's brood pouch to the feet of the father, where it is covered by a protective flap of skin. Thus they are spared the problem of nest—building with sparse materials and are guaranteed that the egg will be in a safe, temperature—controlled environment.

After a plaintive song of parting, the female vanishes into the darkness to ice—free waters that are penguin feeding grounds. The male is left to care for the egg for at least two months. During that time he will partake of no food and will conserve his energy and blubber by moving infrequently. He will endure the harsh Antarctic winter with its furious, almost daily snowstorms and cold that descends as low as —110 degrees Fahrenheit, with winds up to 160 miles per hour.

When a storm breaks, the fathers huddle and press together against one another, forming a sort of carousel that revolves slowly in a spiral. In this manner the rotating motion exposes each in turn to the raging wind while the others are protected. Each also individually migrates to the warm carousel center. Only by this cooperative behavior are they able to survive the severest of storms. As soon as the storm subsides, the carousel breaks up but is quickly re—formed whenever a new storm approaches.

If, during the period of incubation, the male discovers the egg to be infertile, he will toss it away and head for the fishing grounds, but fathers with an egg to nurture remain faithful to their tasks. Encumbered as he is by the egg nestled on his feet, and emaciated from his months of starvation, the male would be defenseless against predators. Fortunately, and after generations of advance planning, the penguin has selected a season when no predators are about.

Most eggs do survive, and when the fledgling hatches, the father penguin feeds it a milklike secretion from his crop. The female returns, usually in June, with a gift of food for her husband; at this time she takes over the main activity of parenthood. During the next several months each parent will continue to spell the other in the rearing of their offspring.

This is the happy season for the emperor penguin families. Infants are discovering the pleasures of tobogganing, which is the penguin's swift and easy method of moving on ice. They learn early to huddle together to keep warm, since they are more sensitive to cold than are adults. They are also vulnerable to birds such as petrels, skuas, and terns that breed on many of the Antarctic islands. Their greatest protection from the predators is provided by the immature yearlings, whose typically teenage nuisance value discourages all intruders.

As the spring thaw in late September breaks up the ice, young and old leave the colony for the open sea. Hunting for food in the expanses of the ocean is not a communal activity, so the parents quickly lose contact with each other and with their six—month—old. The young penguins will learn the lessons of fending for themselves with no further help from their parents. Yearlings will eat heartily in preparation for returning to the breeding ground, and adults will spend the next five months regaining their strength for the next season of child rearing.

From the book: 
Our Fascinating Earth