

Dolphins stay awake for 15 days by sleeping with one half of brain - 001sky
http://www.telegraph.co.uk/earth/wildlife/9616671/Dolphins-stay-awake-for-15-days-by-sleeping-with-one-half-of-brain.html

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zoowar
Unihemispheric slow-wave sleep
<https://en.wikipedia.org/wiki/Unihemispheric_slow-wave_sleep>

