Do Blue Whales Sleep? – Useful Guide

do blue whales sleep

The thought of the biggest animal on earth shutting down to sleep may seem a little odd to some, but it’s a crucial part of survival for all mammals, even the blue whale.

Without sleep, whales, just like humans can be groggy and not perform at their best, which in the wild could be the difference between life or death.

In this post, we’re going to take a closer look at the blue whale’s sleep pattern, and specifically answer do blue whales sleep?

Yes, they do. Sleep is just as crucial as it is for whales as it is for us humans, and it’s an essential part of a blue whale’s routine.

Do Blue Whales Actually Sleep?

Like humans, sleep is an essential part of allowing a whale’s brain to recover, and prepare for the next day ahead.

It gives their minds and bodies a chance to shut down and recharge, allowing them to stay on top of their game.

Blue whales, despite their massive size also need sleep to remain on top form. However, the way whales sleep varies between different species and is a lot different from how humans sleep.

As humans, we are unconscious breathers, which means we breathe naturally without thinking about it, allowing us to easily breathe whilst sleeping.

Whereas whales as conscious breathers, meaning they have to actively decide when to breathe which can make sleeping underwater more tricky.

Thankfully, whales are well suited to life underwater. They have developed methods that allow them to sleep underwater and stay alert too.

All whales sleep, but depending on their size and species they each have different requirements.

Since it’s difficult to study a whale’s sleep in the wild, there isn’t a great deal of information on the blue whales sleeping habits, with varying information being reported.

Not only that, but the fact that blue whales are incredibly rare in the wild makes it even more difficult to track their sleep.

How Do Blue Whales Sleep?

What we do know is that blue whales sleep near the surface, allowing them to stay conscious enough to breathe whilst sleeping.

They don’t sleep for very long at one time, it’s usually more a 30-minute nap than a full sleep. However, it’s long enough so that their batteries can recharge, and they will have regular napping periods.

Blue whales are unable to sleep for long periods as although they have very few natural predators, they don’t want to get caught off guard by ships or other hazards.

Killer whale pods have been known to attempt to bring down blue whales, so it’s not wise for them to be idle for too long.

Not only that, but the longer they stay motionless, the cooler their body temperature gets, so 30 minutes seems to be the ideal nap time for most whales.

Check out this footage of a blue whale getting some shut-eye:

One of the more common assumptions is that blue whales, like many other species, sleep with one eye open and with only half of their brain shut down.

They are thought to do this to stay aware of what is going on around them as well as keep an eye out for predators and potential problems, and remember to breathe.

Do Blue Whales Sleep At Night?

The blue whale feeds almost exclusively on krill, which are small crustaceans that the whale scoops up in large quantities and then sieves out with its baleen.

During feeding season, blue whales can consume as much as an eye-watering 40 million krill every single day.

In some locations, studies have shown that krill perform a vertical migration when dusk approaches.

This means that the krill that blue whales feed on come closer to the surface as the sun starts to go down. As the krill come up, so does the blue whale, making it easier for the whales to feed close to the surface.

If the food is closer to the surface, this means that blue whales don’t need to dive as deep in order to feed, allowing them to be close to the surface at night.

This is thought to be when blue whales will sleep for short periods, suggesting that blue whales do sleep in the nocturnal hours.

Sleeping at night also offers blue whales the most protection. They are incredibly large whales that could be seen from afar, so sleeping under the cover of nightfall makes sense for the blue whale.

Do Blue Whales Sleep Upside Down?

As far as we know, blue whales do not sleep upside down.

They sleep upright, in a half-conscious state close to the surface that allows them to breathe when needed.

Some species of whales, such as the sperm whale sleep in a vertical position when they take short 10 – 15 minute naps.

Final Thoughts

Do blue whales sleep? Absolutely, just like all species. In fact, scientists are yet to find an animal that does not need sleep to survive.

Sleep is crucial for recharging our batteries and allowing us to tackle the next day as best we possibly can.

Blue whales sleep near the surface and take short naps to allow them to recharge. However, they stay in an almost half-conscious state in order to keep an eye on what is going on around them.

Predators and incoming ships could cause them harm, so they need to sleep with one eye open (literally) in order to stay on guard.

Sadly there is not a lot of research on how blue whales sleep, but hopefully in the future scientists can gather more information on the blue whale’s sleep patterns.

Hopefully, this post has been useful and you’ve learned something new about how blue whales sleep.

Thanks for taking the time to read this post and feel free to stick around to learn more about marine wildlife and the beautiful blue whale.

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