Animals That Sleep Standing Up: How Do They Do It?
You probably already knew that some animals sleep standing up. A close example of this behavior is urban birds, such as pigeons, which stand upright while tucking their heads under their wings.
However, when thinking about a human sleeping standing up, the first thing that comes to mind is that his knees will buckle and he will fall to the ground. Based on this premise, would you be able to explain how it is possible that some animals are able to sleep in such an awkward position? Here, we’ll give you the answer to that and many other questions.
Why are there animals that sleep standing up?
There is a simple logic behind this phenomenon. If you think about it, most animals that sleep standing up are prey: cattle, birds, horses and others. However, it’s easy to see large predators – cats at the top of the food chain, for example – sleeping totally relaxed and exposed.
So why do prey sleep standing up? Most of them need to remain in position to facilitate their escape in the face of a possible attack. Survival is the key, as taking a few seconds to get up could mean death if a predator is lurking.
How can they sleep standing up?
Although the above explanation makes sense, there is another question to be resolved: how is it possible that these living beings do not fall while they are sleeping? Muscles relax during sleep and, in principle, would not be able to support the body.
However, animals that sleep standing up have different mechanisms, depending on the species, that allow them to remain in that position. In general, their anatomy favors joint blockages, which allows them to relax without collapsing.
On the other hand, sleeping standing up is not the only strategy that minimally guarantees your safety. Most of these animals do not sleep for many hours at a time, dividing their sleep into short naps. This in turn helps them combine alertness with eating for several hours a day.
Some animals that sleep standing
If you are curious to know examples of animals that sleep standing up, here are some that will allow you to get a broader view of this survival mechanism. Check out:
- Horses: These horses block the joint that joins the femur, tibia and kneecap, allowing them to relax without bending the legs.
- Giraffes: Giraffes sleep at short intervals of 10 minutes, up to a total of 2 hours a day. Thus, supporting all your weight on your feet is not harmful, given their anatomy and size.
- Flamingos: Like other birds that sleep on one leg, flamingos can lock the knee joint to balance on it while putting their head under the wing.
- Elephants: Like giraffes, elephants sleep an average of 2 hours a day. They can go up to 48 hours without sleep if need be. In addition to sleeping standing up, they also have their eyes open, so researchers need to be guided by their trunk activity to determine whether these animals are awake or not.
- Passerine birds: these birds would run the risk of falling from the branch on which they rest if it weren’t for the flexor tendons of their legs. These structures close the fingers around the perch, giving the bird a very firm anchor point.
Some animals, especially mammals, combine the two forms of sleep – lying down and standing – according to their needs. In fact, some of them need to sleep lying down to promote salivation and digestion, as is the case with horses and cows.
How, when and where a species sleeps reveals its eating habits, the dangers that threaten it and how it interacts with environmental factors such as temperature, humidity or the seasons. Nothing in nature is casual, since living beings poorly adapted to the environment end up extinguishing with time.
Investigating living beings’ sleep patterns increasingly helps us to understand the dynamics of the natural world. Furthermore, this knowledge can be compared to the sleep of the human species, in order to continue advancing what is known about our own nature.