Biology Is Weird — I’ll Sleep When I’m Dead
Nothing feels better than a cozy nap on a rainy afternoon. Or melting into your bed at the end of a stressful day. I’m sure we can all agree that sleep is a beautiful thing, one that you appreciate more as you get older and life gets busier.
But have you ever wondered what it would be like to run only on catnaps? To never experience that deep sleep that leaves you dazed, warm and loopy. Sounds like a terrible existence? Well, send your condolences to the whales. Because that is their reality.
Whales have the unfortunate honor of being sea-living mammals. Which means they need to breathe oxygen to survive but they also need to stay in the water, and they don’t have gills. Oof. That’s heavy. Imagine trying to sleep but you keep waking up because you’re not breathing. Would that wake you up? Or would you not wake up?
Moving on, because of the paradox of their existence, whales sleep in a pretty interesting way. They turn off only half of their brains, this way, they don’t accidentally take one huge fatal breath of ocean. This is called ‘unihemispheric sleep’. Some types of whales even go as far as sleeping vertically close to the surface.
But the ocean is a dangerous and scary place, even for the natives. Sleeping close to the surface leaves whales exposed so they tend to sleep in groups and use the alert half of their brain to stay conscious of their surroundings.
Dolphins are faced with a similar dilemma. Both animals literally sleep with one eye open. The right eye is open when the right side of the brain is resting and vice versa. Whales sleep for about 10 to 30 minutes only at a stretch while dolphins can manage to catch a few hours while oscillating the side of the brain that’s resting. Some species of whales are believed to spend only about 7% of the day asleep, that’s less than 2 hours! But a mammal’s got to live right?
Dolphins sleep at night, but are awake in the later hours to catch those yummy midnight snacks. They can be found resting horizontally or swimming slowly and steadily close to the surface, and in shallow waters, they’ll lie down on the seabed and rise to breathe when necessary.
I for one am glad that I’m a land-living mammal because I think sleep is so cool, I do it for fun. That’s it for today. Shoutout to the dolphins and whales that agreed to be interviewed and provide information for this article, much love. Hope you learned something or at least smiled once. Thank you for coming to my TED talk.
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