Sleeping Giants: Do Humpback Whales Sleep?

do humpback whales sleep

Imagine yourself as a snorkeler crossing ways with a pod of floating whales. If you encounter such a scenario, it means that you have come across sleeping whales.

The question here is “Do humpback whales sleep?” The simple answer to this goes by saying that YES, they do!

Yes, humpback whales sleep. One-half of their brain stays continuously active to remind them that they need intermittent breaks to breathe while they are sleeping. 

They sleep for a maximum of 30 minutes so that their body temperature does not lower due to inactivity. Their sleeping behavior is referred to as “cat nap” because they sleep for a short period of time.

sleeping less avoids their chance of drowning and helps them to retain control of their blowhole.

They do not respire like fish, because they do not have gills, they have specialized lungs but still do not breathe like humans

This seemingly simple answer has many inquisitive follow-up questions like; do they sleep while at rest or while swimming?

Do they sleep above or under the water? What else is going on in their body when they doze off and peacefully dream? Are there skulking predators, trying to find them, and outbreaks while they are sleeping? 

One fact that answers all these questions is that “all the species of whales sleep” in the ocean where they eat, play, breed, and interact with swimmers. However, you would be shocked to know how long they sleep.

Do Humpback Whales Really Sleep?

Humpback whales need to sleep like all other mammals. The mode of sleeping is different than other mammals.

They have lungs to breathe air just like you, but the real challenge for them is to keep breathing while they are asleep.

They have to put in a lot of effort to sleep and not drown in a lack of oxygen. 

How Long Do Humpback Whales Sleep?

It is very important to know where and how they sleep to clearly understand how long humpback whales sleep.

It could sleep for longer if it breathes and sleeps at the same time. The sleep is for as long as 30 minutes.

The duration of sleeping is species-specific. Some species of whales have been reported to be found sleeping for 2 hours. 

A humpback whale sleeps seven percent of its day. It’s a good way that it can get much-needed rest while staying safe.

Sleeping less avoids their chance of drowning and helps them to retain control of their blowhole.

This blowhole is a small flap of skin that can open and close by an animal’s voluntary control. The whales come to the surface of the water to expel air through this hole. 

Here you might be wondering how and when the sleep cycle of a whale starts and ends.

There is a 24-hour cycle through which all animals go through; it is called the circadian rhythm. Whales often do sleep for slightly longer periods at night.

They take prolonged breaks during the night to recharge them for the next day. This depends on the time of the year that they may have to continue migration or nurse their young ones.

The duration of sleeping is affected by body temperature as well, if it loses too much of the body temperature then it becomes inactive.

Where Do Humpback Whales Sleep?

Interesting thing is that the diet of a humpback whale plays a vital role in getting to know where they sleep.

As mentioned earlier, humpback whales need to breathe using their blowhole; for this reason, they keep themselves close to the surface. This way they can readily get up and breathe the air they need. 

They need to keep the temperature of their body in a definite range. Heat is lost at a much faster rate in the water than it is in the air. For this reason, a whale needs to keep on moving.

How Do Humpback Whales Sleep Without Drowning?

The Humpback whales are “conscious breathers”, which means that they have to voluntarily decide when to breathe. They need their blowhole to be on the surface for active breathing. 

The fun fact here is that their brain sleeps half and half, one by one. This way they stay alert all the time.

One hemisphere of the brain along with the opposite eye stays awake while the other hemisphere sleeps.

In this way, the half that is awake keeps reminding the whale that it has to breathe. 

The activeness of their half brains makes them watch for lurking predators or any obstacle, protect other pod members efficiently and follow each other league. If the whale had to sleep the way you do, it would drown. 

More On Humpback Whales Sleeping

All the whale species protect their pod members. They are also seen sleep-floating along with other pod members.

Their sleep positions also vary, they may be found sleeping in a horizontal position, or in a vertical upside-down position.

They have specialized lungs to take in more air than is possible for you. They continue floating on the surface of the water without perturbing that they would sink because of the amount of blubber present in their bodies. This makes them very buoyant creatures in the water. 


To summarize the sleeping behavior of humpback whales, it is very important to remember that they voluntarily take every breath.

They are excellent migrators; they may migrate as far as 5000 miles. Migratory habit has built the ability in their body to hold their breath for a surprisingly long period. 

They sleep with one eye open and half of their brain. The alertness of their half-brain actively reminds them to breathe.

So next time you see a very slow-moving or floating whale at or near the surface of the water, don’t make a sound and allow the mammal to take its power nap.