These penguins sleep for a few seconds... and start over a thousand times.

Four seconds of sleep almost doesn’t count. In jugular penguins followed during nesting in Antarctica, this duration corresponds to the average of thousands of episodes. The birds were constantly interrupting their sleep, instead of regrouping their rest over a long continuous period.

To verify this, the researchers recorded their brain activity. They identified slow sleep affecting one or both hemispheres, with more than ten thousand episodes daily. Combined, these fragments accounted for more than eleven hours of sleep per hemisphere each day. The total is considerable, even if each of its small units seems derisory.

The animals were able to reproduce under these conditions. This suggests that certain benefits of sleep can accumulate despite extreme fragmentation. The study does not show that four seconds would be enough for humans, nor that penguins sleep like this in all situations. Above all, it reveals how a common need can take an unexpected organization.