Gentoo Penguins (Pygoscelis papua)
The Gentoo Penguins, Pygoscelis papua, 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.
Two sub-species of this penguin are recognised: Pygoscelis papua papua and the smaller Pygoscelis papua ellsworthii.
In the water, sea lions, leopard seals, and orcas are all predators of the Gentoo. On land, there are no predators of the full-grown Gentoos, but birds have been known to steal their eggs and chicks.
They are the fastest underwater swimming penguins, reaching speeds of 36 km/h.
The exact origin of the name Gentoo is unclear. It was used during the 18th century by both British and Portuguese (originating in the latter case from gentile) to refer to various ethnic groups, notably as a derogatory term for Hindus.
Description:
It is easily recognised by the wide white stripe extending like a bonnet across the top of its head. It has been speculated that the characteristic white spot of the Gentoo penguin may have been seen as similar to a turban.
Males have a maximum weight of about 8.5 kg (18.8 lbs) just before moulting, and a minimum weight of about 5.5 kg (12 lbs) just before mating.
For females the maximum weight is 7.5 kg (16.6 lbs) just before moulting, but their weight drops to below 5 kg (11 lbs) when guarding the chicks in the nest.
Adult Gentoos reach a height of 75 to 90 cm (30-36 in), making them the largest penguins outside of the two giant species, the Emperor Penguin and the King Penguin.
Chicks have grey backs with white fronts.
Nesting / Breeding:
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.
Diet / Feeding:
Gentoos live mainly on crustaceans such as krill, with fish making up only about 15% of the diet. However, they are opportunistic feeders, and around the Falklands are known to take roughly equal proportions of fish (Patagonotothen sp., Thysanopsetta naresi, Micromesistius australis), crustaceans (Munida gregaria) and squid (Loligo gahi, Gonatus antarcticus, Moroteuthis ingens).
Status
Lower Risk – Near Threatened (IUCN Red List)
