Rockhopper display Penguins indulge in strange postural displays and calls in the process of finding mates within their own species. Magellanic Penguins on grazed field in the Falklands Penguins vary in their nesting methods, and some species build no nests at all. The Humboldt and jackass penguins prefer a sheltered retreat, such as a burrow, and utilize sticks and other debris to form the nest. Others, such as the Ad lies, incubate their eggs in the open on nests formed of stones or sticks. King Penguin with chick Most species of penguin lay a clutch of two eggs, which are white or greenish in color.
Incubation periods vary according to species.
King penguin eggs require more than 50 days of incubation before hatching, whereas jackass eggs hatch in 32 to 36 days. In general, both sexes incubate the eggs and feed the young. The male Ad lie penguin usually incubates the eggs for the first two weeks, fasting, while the female returns to the sea to feed and bathe. The male has been known to fast during the entire time that the nesting territory is established and defended, courtship takes place, and the eggs are laid and incubated. When the female takes its turn at the brooding, the male goes to the distant sea to feed and, within an amazingly short period, restores its reservoir of fat and returns to the rookery with food for the young soon due to hatch.