Gentoo Penguin - Breeding

Breeding

The breeding colonies of gentoo penguins are located on ice-free surface. Colonies can be directly dependent on the shoreline but also considerably are located inland. They prefer shallow coastal areas and often nest between tufts of grass. In Georgia, for example, breeding colonies are two kilometers inland. Whereas in colonies farther inland, where the penguins nest between tufts of grass, they shift location slightly every year because the grass may get trampled over time.

Gentoos breed on many sub-Antarctic islands. The main colonies are on the Falkland Islands, South Georgia and Kerguelen Islands; smaller populations are found on Macquarie Island, Heard Islands, South Shetland Islands and the Antarctic Peninsula. The total breeding population is estimated to be over 300,000 pairs. Nests are usually made from a roughly circular pile of stones and can be quite large, 20 cm high and 25 cm in diameter. The stones are jealously guarded and their ownership can be the subject of noisy disputes between individual penguins. They are also prized by the females, even to the point that a male penguin can obtain the favors of a female by offering her a nice stone.

Two eggs are laid, both weighing around 500 g. The parents share incubation, changing duty daily. The eggs hatch after 34 to 36 days. The chicks remain in the nests for about 30 days before forming creches. The chicks molt into sub-adult plumage and go out to sea at about 80 to 100 days.