Gentoo Penguin

Pygoscelis Papua

Gentoo: Image

Description

The Gentoo Penguin is one of three species in the genus Pygoscelis. Mitochondrial and nuclear DNA evidence suggests the genus split from other penguins around 38 million years ago, about 2 million years after the ancestors of the genus Aptenodytes. In turn, the Adelie Penguins split off from the other members of the genus around 19 million years ago, and the Chinstrap and Gentoo finally diverging around 14 million years ago.Males have a maximum weight of about 8.5 kg (19 lb) just before molting, and a minimum weight of about 4.9 kg (10.8 lb) just before mating. For females the maximum weight is 8.2 kg (18 lb) just before moulting, but their weight drops to as little as 4.5 kg (10 lb) when guarding the chicks in the nest. Birds from the north are on average 700 g (1.5 lb) heavier and 10 cm (4 in) taller than southern birds Gentoo penguin reaches 75–80 cm. They are the fastest underwater swimming penguins, reaching speeds of 36 km/h. Gentoo are adapted to very harsh cold climates.

Gentoo: Text

Habitat

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.

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

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, crustaceans and squid.

Threats

In the water, sea lions, leopard seals, and orca are all predators of the Gentoo. On land there are no predators of full grown Gentoos. Skua can steal their eggs; however, some other seabirds have managed to snatch chicks.

Gentoo: Text