How Deep Can Penguins Dive? Emperor and King Penguin Records

Penguin dive records

Scientists measure penguin dives by attaching small, harmless time-depth recorders to the birds’ feathers. The first such devices were used on emperor penguins in the early 1970s. They revealed that penguins dive far deeper and longer than anyone had expected.

These are maximums from tracking studies. Record figures come from a handful of individuals, and because more birds are tracked every year, the records may still be broken.

Emperor penguins: the deepest-diving birds

The emperor penguin is the champion diver among birds. In early studies, emperors were recorded at depths of about 265 m (870 ft). Later tracking found a small female diving to 535 m (1,755 ft) near McMurdo Sound, and emperors from a colony in eastern Antarctica reached 564 m (1,850 ft). The longest dives recorded have lasted more than 20 minutes, with a maximum reported of about 27 minutes.

Record dives are exceptions. Most emperor dives last only a few minutes, and many are shallow, as birds pick off fish just below the sea ice or chase prey in the upper water column. Very deep dives are thought to target fish and squid near the seabed.

At 564 m, the water pressure is about 57 times that at the surface. Very few air-breathing animals can cope with that, and among birds only the emperor is known to go so deep.

King penguins: deep and frequent

The king penguin is the second-deepest diver. During the day, kings make repeated dives to about 100–300 m (330–980 ft), each lasting around five minutes, to hunt lanternfish and squid. At night, when their prey rise toward the surface, they dive to less than about 30 m (100 ft).

The deepest king penguin dive recorded is about 343 m (1,125 ft), near the Falkland Islands, and the longest lasted about 9 minutes. Unlike most penguins, kings often make flat-bottomed dives, descending to a chosen depth and hunting there before returning to the surface.

How penguins cope with depth and low oxygen

Penguins dive on a single breath, so they must make the most of their oxygen and withstand crushing pressure. Their adaptations include:

• Solid bones: unlike most flying birds, penguins have dense bones without large air spaces, which reduces buoyancy and the risk of pressure damage.
• Oxygen stores in the muscles: penguin muscles are very dark because they contain large amounts of myoglobin, a protein that stores oxygen.
• A slow heart: during long dives, an emperor’s heart rate can drop to about 15–20 beats per minute.
• Rationing blood: blood flow to non-essential organs is cut back, saving oxygen for the brain and heart.
• Tolerance of low oxygen: emperor penguin hemoglobin keeps loading oxygen at levels that would make many animals lose consciousness.

How penguins avoid decompression sickness, sometimes called “the bends”, is still being researched. Their limited lung air, slow heart rate and changes in blood flow probably all help.

Swimming speed

Penguins are fast, efficient swimmers. They “fly” underwater with stiff flippers, generating thrust on both the upstroke and the downstroke. Emperors usually cruise at 6–9 km/h (4–6 mph), and king penguins at about 6.5–10 km/h (4–6 mph). The gentoo penguin is often described as the fastest, with bursts of up to about 36 km/h (22 mph).

Many penguins also “porpoise”, leaping clear of the water as they swim near the surface. This lets them breathe without slowing down, and leaping out of the water is also how they land on ice floes or rocks.

Why do penguins dive so deep?

Penguins dive to find food. Deep dives let emperors and kings reach rich supplies of fish and squid that smaller birds cannot. Size matters here: bigger bodies store more oxygen and use it more slowly, so the largest penguins can stay down longest. Smaller species such as Adélie and little penguins feed mainly on krill and small fish near the surface. For more on their prey, see what do penguins eat?

Diving mammals do even better. Some seals go much deeper than any penguin, as explained in how long can seals hold their breath?