Which bird dives the deepest?

The emperor penguin is the deepest-diving bird. It can descend to roughly 550 metres while hunting beneath Antarctic sea ice, deeper than any other bird species on record.

Emperor penguins dive to pursue fish, squid and krill, often in almost complete darkness. Their streamlined bodies, dense bones and powerful flippers help them swim efficiently underwater, while specialised oxygen storage lets them remain submerged for extended periods. A single dive can last more than 20 minutes, although many feeding dives are shorter.

The king penguin is a common mix-up because it is also an excellent diver and has been recorded below 300 metres. The emperor penguin is larger, however, and its deeper dives take it into a different class of underwater performance. This ability is especially important during the Antarctic winter, when adults may travel beneath sea ice to find food for their chicks.

Emperor penguins are also the largest living penguins. Their deep-diving record is not the same as their speed or endurance record: different species excel in different aspects of swimming, and dive depths can vary with food availability and measurement methods.