May 1, 2019
The penguin diet consists mainly of fish and squid and crustaceans. In the Antarctic, the smaller penguins mostly feed on shrimp-like krill.
Although krill are small (up to 5cm in length) they form dense swarms which are a rich food source. Penguins can adapt their diet to what is available, and their diet varies considerably with season.
Electronicdive recorders fitted to the backs of penguins give a picture of their feeding habits, recording the times and depths of their dives. The deepest diving penguins are the kings and emperors as they search for squid and fish — the record holder is a female emperor penguin who reached an astonishing 535 metres.
Though the smaller penguins do not reach such depths, for their size their diving performance is just as remarkable. Gentoo penguinsdive to 150 metres, and a quarter of their dives exceed 100 metres — inextreme cases they can dive almost continuously for 15 hours, completing over 450 dives.
May 1, 2019
A healthy adult penguin on land has no natural predators, though eggs and chicks are eaten by other birds (skuas and giant petrels).
Penguins usually live in places free of land predators, against which they would be defenceless. However, in water, penguins are hunted by leopard seals and killer whales. Leopard seals cruise the ice edge next to penguin colonies, waiting for the birds to plunge into the water.
May 1, 2019
Penguins are sociable creatures both on land and at sea. Their colonies — known as rookeries — are often huge, with up to a million nesting pairs. In the pure Antarctic air, you can smell a penguin rookery from a long way away! Penguins generally breed on exposed rock, beaches or tussock grass, with the exception of the emperor, which
breeds on sea-ice.
Monitoring a penguin colony involves counting the penguins daily over many months, to find out the timing of events such as egg laying and hatching. With thousands
of pairs in a colony, this is not an easy task! When adults return fromthe sea to feed the chick their diet is analysed. Satellite tracking monitors the location of penguins at sea. All this data is tied in with information about the krill, fish and squid in the nearby waters to build up a picture of how penguins go about their business.