• Question: do whales sleep, just generally any species?

    Asked by to Aimee, Chris, Dave, Greig, Laurence on 16 Jun 2014. This question was also asked by .
    • Photo: Greig Cowan

      Greig Cowan answered on 16 Jun 2014:

      Whales (and dolphins) do sleep, but I think it is more of the type of sleep that we have when we are just about to drift off. Obviously we breathe automatically, but for whales it is a bit more difficult since they need to be near the surface and to actively breathe. Therefore, when they sleep, part of their brain still needs to operate so that they can take air in through their blow-hole.

      Sleep is quite an active area of research in general since we still don’t really understand what it is all about. Scientists use tools like electroencephalography (EEG) to study brain waves during sleep, showing that we have different periods of sleep.

    • Photo: Laurence Perreault Levasseur

      Laurence Perreault Levasseur answered on 16 Jun 2014:

      Yes, whales, and all vertebrates we know of, do need to sleep. Sometimes the sleep patterns are very different than what we, humans, do. For example, giraffes sleep only for 30 min a day, spread in many sessions, when they sleep super deeply. Others, like koalas, sleep about 20 hours a day!

      Some animals also have very different ways of sleeping. That’s the case for whales and dolphins (gave more details in your other question about this), but also for migratory birds. Some of them take power-naps of just few seconds, often while they are still flying!! That means some birds species don’t have to stop to sleep!

      For invertebrates, it’s a lot harder to study, so for fish and frogs it’s pretty hard to say if they actually sleep or if they just rest (my office fish definitely seem to sleep at night, but then I don’t have an electroencephalogram to test it!). Apparently insects, however, do stop their activities to sleep.

    • Photo: Dave Jones

      Dave Jones answered on 16 Jun 2014:

      They do, just not in the same way that we do. While they are asleep they still have control of their blowhole so that they don’t let water in and drown. Depending on the species, they sleep in different ways. Some don’t ever sleep completely, resting parts of their brains why the other parts keep an eye out for predators and look after their breathing. Others do sleep completely but only for very short periods, before waking up, making sure everything is ok, breathing and then going back to sleep. A sort of extreme power napping which they can do because they can hold their breath for way longer than we can.

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