Penguins cannot breathe underwater.
They are birds, and they breathe air with lungs. Before a dive, a penguin breathes at the surface. Underwater, it relies on oxygen already stored in the body and on physiology that saves oxygen.
That is why “swims well” and “breathes underwater” should not be mixed. Penguins are diving air-breathers, like seals and whales, not gill-breathing fish.
How penguins stretch a dive
Penguins can store oxygen in blood and muscles. During a dive, they can prioritize oxygen for important organs and adjust heart rate and activity.
Species differ a lot. The emperor penguin is one of the strongest deep-diving penguins. Smaller penguins usually dive for shorter times and to shallower depths.
For numbers and comparisons, read how long penguins can hold their breath and penguin diving physiology.
Why penguins dive at all
Food is in the sea. Fish, krill, and squid do not come onto shore by themselves.
Penguins have to dive, chase, catch, swallow, and return to the surface to breathe. During breeding, adults also have to bring food back to chicks. Diving ability is therefore connected to survival and breeding success.
FAQ
Do penguins have gills?
No. Penguins are birds and breathe with lungs, not gills.
How can penguins dive for so long?
They store oxygen in blood and muscles and adjust heart rate and energy use during dives.
What happens after a dive?
They return to the surface, breathe, and prepare for the next dive.
