Two sub-species of this penguin are recognized: Pygoscelis papua
papua and the smaller Pygoscelis papua ellsworthii.
Males have their maximum weight of about 8 kg just before moulting
and their minimum weight of about 5.5 kg just before mating.
For females the maximum weight is 7.5 kg just before moulting
but their weight drops to below 5 kg when guarding the chicks
in the nest.
Gentoo Penguin Breeding
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. Two
eggs are laid, both weighing around 130 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 crèches. The chicks moult into sub-adult plumage
and go out to sea at about 80 to 100 days.
Feeding Habits of Gentoo Penguins
Gentoo penguins 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,
Gentoos live mainly on crustaceans such as krill, with fish
making up only about 15% of the diet.
Predators of the Gentoo
In the water, sea lions, leopard seals, and orca, 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
Scientific Classification of the Gentoo