Gentoo penguins

Gentoo penguin with chicks
Gentoo penguin with chicks (Photo: Greg Stone)
Gentoo penguins in snow on Macquarie IslandGentoo feeding timeGentoo penguin and chick

Scientific name: Pygoscelis papua

Physical description and related species

Gentoo penguins are the third largest penguin species alive. Adults weigh 5–8 kg but how heavy they are depends on the phase in their annual cycle. Males tend to be larger than females but the difference can be difficult to see.

A bright red-orange bill and conspicuous white eye patches make both adult and juveniles easily distinguishable from other species of penguin.

Gentoo penguins are closely related to the Chinstrap (Pygoscelis antarctica) and the Adélie (Pygoscelis adeliae) penguins.

Distribution and abundance

Gentoo penguins have a large geographical range as they breed on many sub-Antarctic islands and on the Antarctic Peninsula. The largest populations of gentoo penguins are found at the Falkland/Malvinas Islands, South Georgia, and the Antarctic Peninsula.

With a total breeding population of approximately 387 000 pairs gentoo penguins are the least abundant of the penguins found on the sub-Antarctic islands. Their global population is probably stable; in their southern range, especially at the Antarctic Peninsula, gentoo populations may be increasing but they may be decreasing in the southern Indian Ocean.

Conservation status: near threatened

In the past, humans collected the eggs of gentoo penguins, particularly at the Falkland/Malvinas Islands but this activity has been greatly reduced. At the Falklands, the penguins share their colony grounds with grazing animals, such as sheep and cattle, who can trample nests.

Breeding

Gentoo penguins start breeding when they are 2–4 years old. They exhibit far more variability in their breeding cycle than other penguins. For example, the mean laying date is 26 October at South Georgia but 27 July at the Crozet Islands. The females produce two eggs. Once laid, they are incubated for 34–37 days. The chicks start to form créches when they are about 26 days old. They fledge at age 80–90 days.

Gentoos build nests on beaches or amongst tussocks and keenly defend their turf. But each year the location of their breeding colony is slightly different. While Adélie penguins, for example, often return year after year to the same nest sites, gentoos may occupy a new area near where they were the previous year. They occupy their islands generally all year round.

Diet and feeding

The diet of gentoos is quite varied as they are opportunistic hunters. The composition of their diet varies with season and location but is usually a mix of crustaceans, small fishes and squid.

Gentoo penguin eggs are taken by skuas. Young birds are preyed upon by sheathbills, caracaras (falcons), kelp gulls, giant-petrels and feral cats, while older birds are taken by leopard seals. Nests are often flattened by indifferent elephant seals as they move about the island.