Whales are air breathing mammals like you and me. But unlike us, they must surface to breath. How do whales sleep and not die or pass out through a shortage of oxygen?
In fact, whales spend most of their life underwater and rarely come up for air. To make sure they don’t suffocate, all whales have a unique organ called the baleen plate that helps filter food particles from the water. This filtering system works best when it’s kept clean, so whales must regularly blow bubbles to keep debris away from their mouth, nose and eyes.
The video above explains why whales use bubble blowing to breathe. And while we’re here, check out our other videos about animals that sleep upside down, sleep standing up, sleep walking, sleep talking, and sleep eating.
Whales are known as “whale breathers” because unlike most mammals, they don’t inhale air through their nostrils like we do. Instead, they exhale air out of their blowholes. And just like us, whales use their brains to control their breathing. They have the ability to voluntarily regulate how much oxygen enters their bodies and how long it stays there.
This voluntary system means they must maintain awareness of their surroundings, including where their blowhole is located. If they become unconscious, they could drown.
Unlike us, however, whales are able to keep their brains active during sleep. In fact, some species of whale spend up to 20% of their lives sleeping. So while our brains are resting, they’re still keeping tabs on what’s happening around them.
If an Orca were to drop off into deep sleep, they’d find themselves underwater without knowing why. Their lungs would fill with water, causing them to drown. But if they kept their eyes open, they’d be able to see the surface of the ocean, allowing them to know enough to take a breath and save themselves.
Sleep with one eye open!
Some whales and dolphins adapt the how they sleep by allowing only half of their brains to sleep at once. While the rest of the brain sleeps, the remaining half keeps watch over the environment around them. This attentive half of the brain helps whales and dolphins to remember where they left off swimming, and to avoid obstacles and predators.
The awake half reminds the whale when it needs to come up to the surface, as it swims. Generally, a single whale stays close to the others in the group while asleep.
After a maximum of two hours of continuous wakefulness, the whale switches sides and lets the sleeping half of its brain take over again.
This process is often called ‘cat-naping’. Other large cetaceans, like sperm whales, are able to hold their breaths long enough to remain motionless under water while sleeping.
Orcas have some pretty big brains. They’re one of the few species of cetacean (a group of animals that includes whales, dolphins and porpoises) with large brains relative to their body size. Their brains are about twice the size of those of other cetaceans, including bottlenose dolphins and killer whales. But what does it mean for us?
The first thing we notice is how huge their brains are compared to our own. A typical adult human brain weighs around three pounds (1.4kg), while an average Orcas’ brain weighs up to 15 pounds (6.9kg). However, their brains are still smaller than those of elephants, whose brains are over 20 times heavier than ours.
What do orcas think about?
Scientists aren’t sure exactly what role the enlarged paralimbic lobes play in orcas’ cognition. One theory is that it helps them process information faster, allowing them to make decisions based on emotional responses rather than just rational thought. Another idea is that the lobes allow orcas to remember things better, perhaps even forming memories.
But there could be another reason why orcas have such large brains. Researchers suggest that the increased volume of gray matter in orcas’ brains might help them communicate more effectively.
Sleep Strategy Used By Dolphins And Whales”
The sleeping strategies of whales and dolphins are just as impressive as you might imagine. While humans tend to fall asleep with both eyes closed, cetaceans have developed a unique way to doze off without losing consciousness.
Whales and dolphins have the incredible ability to shutdown one of their brain hemispheres and use the other to memorize to breath at the surface. Meanwhile, the eye connected with the awake hemisphere stays open for a few seconds to check for obstacles, predators, or any other problems.
While it seems like a very difficult task, researchers have discovered that these animals can perform this feat quite easily. In fact, many studies show that dolphins and whales spend about 70% of their time sleeping.
How long do whales sleep?
Whales are known for being very active animals. They swim around, eat, mate and play. But what about their sleeping habits? Do they really just lie down and fall asleep like we humans do? Or does it take them hours to finally drift off into dreamland?
Researchers at the University of British Columbia studied the activity patterns of bottlenose dolphins and beluga whales, and found out that they sleep much more than you think. In fact, they found that they could spend over 30% of their day asleep. Sperm whales, however, were found to only sleep for seven hours per day.
The researchers believe that there are many reasons why these differences exist. One reason is that grey whales sleep more intensely than other species. Another reason is that grey whales tend to sleep in deeper water and therefore have less contact with the surface. And perhaps most important, grey whales sleep with one hemisphere of their brain at a time – something no other species seems to do.
These findings show us that the way we define sleep depends on our expectations. We know that people often say that they slept well despite having been awake for 24 hours straight. This is because we are used to sleeping for eight hours every night. However, whales sleep differently, and that makes it hard to compare how long they actually sleep.
A study published in Scientific Reports found that most sleeping mammals are either horizontal or vertical. This includes humans, dogs, cats, elephants, giraffes, horses, cows, pigs, rats, mice, squirrels, bats, birds, fish, frogs, reptiles, and even some invertebrates like crabs.
The researchers used data from previous studies and analyzed it in conjunction with information about how different animals move during sleep. They concluded that most mammals fall into one of three categories:
• Horizontal sleepers—animals that spend most of their sleep near the water’s surface.
• Vertical sleepers—animals whose bodies lie nearly parallel to the ground.
• Deep sleepers—animals who sleep at deeper depths.
Sleep like a baby
The first few months of life are critical for a whale calf. During this period, it needs lots of rest and maternal attention. A study published in Scientific Reports found that mother orcas give birth every three years, and spend about 10 days caring for each calf. This means that mothers must take turns resting and keeping watch over their offspring. And while they’re doing this, they must maintain a constant speed of around 20 kilometers per hour (12 miles per hour).
During their first month, calves do not leave their mother’s side, as they feed exclusively from her milk. However, once they start eating solid food, their diet includes fish and squid. Their mother continues to provide protection and warmth, but she also takes part in feeding and play activities.
In addition to being fed, the calf needs to learn how to breathe water. To accomplish this, the mother orcas teach the calf how to use the blowhole, located near the nose. She blows into the mouth of the calf, which forces air out of the lungs and up through the blowhole. When the calf exhales, the air pushes against the surrounding water, forcing the body upward.
Although the calf does not float upright, it keeps itself afloat thanks to its blubber layer. Its skin is covered with thick layers of fat, which makes it very buoyant. But even though the calf is able to survive without its mother’s help, it still requires close monitoring. If the mother stops swimming, the calf sinks.
We don’t know for sure if whales and dolphins dream. But we do know that they are very intelligent animals. They are known to communicate over long distances, and they use tools to catch fish. They even play games with each other. So it makes sense that they might dream too.
However, there is no scientific evidence that supports the idea that whales and dolphins dream. To date, researchers have been able to find only one study showing that pilot whales and sperm whales show rapid eye movements during sleep. These findings suggest that REM sleep occurs in both species, but the authors note that further studies are needed to confirm this hypothesis.
Interestingly, scientists found pilot whales that showed rapid eye movement while sleeping. This finding suggests that REM sleep does occur in whales. However, this doesn’t necessarily mean that whales dream. Scientists believe that REM sleep is important for memory consolidation and emotional regulation. Therefore, it could simply be that the whale had experienced something traumatic earlier in life, and was remembering it.
In humans, REM sleep is a deep sleep state that occurs just before waking up. During REM sleep, our brains go into “replay mode,” replaying memories and consolidating information. If you’re having trouble falling asleep, try counting sheep. You’ll probably fall asleep faster.