Emperor penguins are the deepest and longest divers

Although all penguins are excellent divers, emperor penguins are the deepest and longest divers. They can descend to depths of about 500 meters and dive for 20 to 30 minutes at a time (over 1,600 feet). Penguins have mastered the capacity to regulate when and how their muscles use oxygen to survive underwater for that long. To keep their muscles active during deep dives, they may either deprive them of oxygen or give them a boost.

Scientists in McMurdo Sound used specific devices to track the muscles of various penguins during dives to understand better how emperor penguins can dive for such an extended amount of time. The penguins spent between 2.3 and 11.4 minutes below in 50 dives that were captured and ranged in depth from 7 to 64 meters (23 to 210 feet).

Researchers discovered that the emperors transported more oxygen from their blood into their muscles only during the penguins' deepest dives. However, they can only sustain this for a limited time until their blood oxygen levels drop too low for the rest of their body. Penguins must return to the surface for air when this occurs. Due to the drawback that the adaptation causes lactic acid buildup, penguins will only engage in this behavior if the reward is a tasty dinner is worth it.