The sperm whale is considered the largest of the whales having teeth and is the largest toothed predator of the sea on the planet. But one of the most exciting and unique facts about it is that they sleep vertically. Yes, that is right. Vertically.But the question why do sperm whales sleep vertically?
In a nutshell, it’s so that they can sail near the surface to stay alert from potential predators. Sleeping vertically helps them breathe when needed and keep one eye open while they sleep! Let’s take a further look at this behavior of sperm whales.
Do Sperm Whales Sleep Vertically?
Yep, sperm whales sleep vertically, which looks a little awkward and rather bizarre at first sight. But it is actually for efficient use. Whales also need oxygen to breathe in the ocean, and they do not have gills like sharks to help them stay submerged. So, they must remain close to the surface to fulfill their oxygen needs.
But Why Do Sperm Whales Sleep Vertically?
Sperm whales sleep vertically to refill their oxygen supply when needed and stay alert to potential predator threats. As discussed earlier, whales need to remain close to the surface for their oxygen, so it makes sense that while they are sleeping, it’s best to be as close to the surface as possible to pop up for fresh air when needed.
But that is not the only reason why sperm whales sleep vertically. This sleeping position also enables them to stay alert to potential predators. Orcas are known as whale killers and are the most significant natural threat to sperm whales. Still, others, like false killer whales and pilot whales, are also known to hunt sperm whales. That is why they need to stay alert while they sleep, and that’s precisely what they do! Literally.
They also keep their brain 50% active while they sleep, ensuring they stay alert, aware, and ready to move if a potential predator moves in too close. Sperm whales can sleep in two exciting ways. They can sleep simply vertically, as we have mentioned earlier.
Second, they can also keep swimming while asleep or sleep while swimming at the surface (also known as logging). These whales are masters of having a quick nap while also remaining alert and on the move if needed; very impressive, right?
Do Sperm Whales Breathe When They Sleep?
Sperm whales have one of the most adaptive sets of lungs in the all marine kingdom. Due to these lungs, they can dive down to depths of 2250m, and the air in the lungs is reduced to 1/4 of the volume on the surface. It simply shows the capacity of their lungs.
This shows that sperm whales can breathe for a very long time, around 90 minutes. This not only allows them to dive into the deep depths for hunting but also means they can hold their breath while sleeping. Sperm whales will hold their breath while they sleep, as they are not required to keep breathing while they are asleep, as they can store vast amounts of oxygen in those big lungs.
How Long Do Sperm Whales Sleep For?
A sperm whale’s sleeping system, unlike humans, needs hours of sleep. This would have them in a pickle, as though their 90 minutes of oxygen would not suffice for the 8 hours we humans require. Thankfully, sperm whales only take naps, generally for 10 – 15 minutes daily.
This cat-napping behavior allows them to benefit from a quick nap while still being able to stay submerged in the water and keep an eye on predators. Research from the University of St. Andrews and the University of Tokyo concludes that sperm whales sleep in about 7% of their daytime; they are one of the most miniature sleep-dependent animals on the planet.
Sperm whales do not properly sleep; short naps give them the most energy to satisfy their sleeping needs. Thus, they utilize their power to float on the surface.
Sperm Whales Sleeping
Sleeping is dangerous for whales. Many hungry predators in the ocean are looking for a hunt that would love to hunt sperm whales. All Whales, including sperm whales, sleep near the surface so that they can breathe when they need to. They breathe consciously, which means they don’t do it as we humans do. Instead, they chose to live because they have a unique and fantastic sleeping ability.
They shut one-half of their brain off while they sleep. This allows them to get some shut-eye while the other half of the brain remains active and alert. These deep-diving whales also sleep close to one another to alert each other from predators quickly. The sperm whale’s sleeping behavior is fantastic. They’re the only whale species that sleep vertically, and doing so provides a bucket of benefits that keep the whales safe.
Final Thoughts
These are the number of reasons why sperm whales sleep vertically. First, stay close to the surface to come up for air when required, and second, keep an eye on predators. They can also sleep while still swimming or floating on the surface. Sperm whales are fascinating sleepers and only nap for a short period, having a total of 7% daytime.
This sleeping allows them to stay active, dive deep into the ocean, and assure them security from predators. Hopefully, this blog has been helpful to you in getting your answer to why sperm whales sleep vertically.