Emperor penguins run on almost empty
Those most familiar of birds that live in the south pole - the wonderful emperor penguins - have an ingenious method of grabbing every last bit of oxygen from their lungs to help them make incredible long dives into the icy waters of the Antarctic Ocean.
That's according to new research from Paul Ponganis and his colleagues at the Scripps Institution of Oceanography in San Diego, California, who strapped oxygen sensors to diving penguins and found that they often come back up for air only when they have drained virtually all the oxygen from their lungs.
In most animals a pigment in the blood called haemoglobin, absorbs oxygen from the air inside the lungs and is then pumped through the blood vessels around the body, delivering oxygen to different parts of the body. Usually, haemoglobin doesn't work very well at very low levels of oxygen, so the last bit is always left behind in the lungs even if an animal is starved of air.
This has lead researchers to think that the haemoglobin of emperor penguin must be a bit special, because it is able to mop up the very last dregs of oxygen in their lungs.
All in all it means that emperors - biggest of all the world's penguins - can make incredible 20 minute dives to over 500 metres down without causing any damage to their body tissues that other animals would suffer from because of a lack of oxygen.
And this means that we are one step closer to understanding how animals can endure such record breaking deep sea dives, and by studying the ability of the penguins to resist damage from low oxygen levels it is hoped that scientists may be able to learn more about how to help to prevent damage occurring to human tissues that are accidentally deprived of oxygen.