Gentoos are the fastest underwater swimming bird, reaching speeds of 36 km/h (22.3 mph).

Statistics
Height: 75cm (29in), Weight: 5.5kg (12lb).

Physical description
Gentoos have white triangular head patches, red bills and brown eyes. Their bodies are black with white bellies, and their feet are yellow.

Distribution
Gentoo penguins have a circumpolar distribution off the Antarctic peninsular and sub-Antarctic islands, including the Falklands and Macquarie island.

Diet
Gentoos are daytime feeders and hunt krill mainly above 50m and fish mostly between 50m and 150m.

Behaviour
Adult gentoos only venture about 24km (15 miles) from the colony in search of food for their chicks. On average they dive deeper than chinstrap and adelies to avoid competition.

Unlike other penguins, such as adelies, gentoos can lay a replacement clutch of eggs if they lose the original clutch.

Reproduction
Gentoos nest in early June, which avoids competition with macaronis. Their nests are made from a pile of rocks, and neighbouring penguins frequently steal pebbles from one another. They tend to lay two eggs, two or three days apart.

The second egg is slightly smaller than the first. Due to asynchronous egg-laying, the first chick to hatch is larger than its sibling, and is therefore more likely to survive.

Most second chicks are unlikely to survive, but if food is abundant, or if the first chick is killed by a predator, they stand a much greater chance of being reared.

Conservation status
There are estimated to be over 250,000 pairs of gentoo penguins, and they are listed as Lower Risk by the 2000 IUCN Red List.

Records
Gentoos are the fastest underwater swimming bird, reaching speeds of 36 km/h (22.3 mph).