Hummingbirds are famous for their brilliant, jewel-like plumage and the rapid flutter of their motions. It seems as if these little animals are never still long enough to sleep.
However, all animals need to sleep, including hummingbirds. These little birds use an enormous amount of energy just to keep themselves alive and moving. Sleep is crucial to replenishing those energy levels, but because of their metabolism speeds and body temperature regulation, hummingbirds cannot sleep in the same way that most birds do.
Hummingbirds do still rest in a state known as torpor, which is a type of nightly hibernation. Torpor is one of those features that makes hummingbirds so unique.
Torpor is a state of deep sleep that resembles hibernation more than regular sleep. During torpor, a hummingbird’s normally rapid metabolism will slow down to a small fraction of its usual function. Its body temperature will also drop by several degrees.
The hummingbird will also slow down its other bodily functions while going into torpor. Its heart rate and breathing will slow down so much that it seems dead.
Torpor allows hummingbirds to conserve their energy and reserve it only for the most essential bodily functions. This is particularly important during colder weather. Hummingbirds most commonly go into torpor to survive cold nights.
Why Do Hummingbirds Go Into Torpor?
It’s not easy being a hummingbird. The birds are famous for their rapid flight patterns, but they require an overactive metabolism to maintain the energy levels needed to keep their wings in constant motion.
Hummingbirds also have a much higher body temperature than most warm-blooded animals, about 104 degrees Fahrenheit. However, they have fewer feathers than other birds and lack an insulating layer of downy feathers. This relative lack of feathers is vital to keeping their body weight sleek enough to fly at the rates that they do, but it robs them of valuable insulation that can keep them warm.
Hummingbirds expend very high amounts of energy to keep their body temperatures up, which is why during the day they feed almost constantly. Since hummingbirds do not feed at night, both because they can’t see in the dark and because they wouldn’t be able to get enough rest if they did so, they do not produce enough energy to maintain normal levels of activity.
By going into torpor and lowering the demands of their own systems, hummingbirds lower the amount of energy that they need to survive the night. They’re also able to maintain temperature equilibrium even during cold nights.
What Position Do Hummingbirds Sleep in?
When going into torpor, most hummingbirds will hang upside down from a branch or a feeder. Their feet are so strong that they can maintain this position even while in a state of deep sleep. Hummingbirds usually choose a secluded branch to go into torpor, such as a dense thicket or bush, so that they can stay safe even while asleep.
Nesting hummingbird mothers will sleep on their nests to keep their eggs and young safe.
How to Tell If a Hummingbird Is in Torpor
If you see a hummingbird hanging upside down in the wild, then there is a good chance that it is in torpor. If you closely observe or even touch a sleeping hummingbird, it may seem dead. That is because these birds barely breathe or move their bodies while sleeping.
Hummingbirds usually come out of torpor an hour or so before dawn. The birds’ internal clocks are attuned to the sun and are waiting for it to be light enough to start feeding. A sleeping hummingbird’s body will start warming up and regaining normal activity gradually, in a process that takes 20 minutes to an hour.
Is Torpor Dangerous for Hummingbirds?
Torpor is vital to hummingbirds’ survival, but decreasing normal bodily functions to such a level is dangerously close to death. To safely go into torpor, hummingbirds go into a feeding frenzy an hour or two before sunset. This allows them to build up an energy reserve that takes them through the night.
Sadly, some hummingbirds do not make it through torpor. If you are not sure if a hummingbird is dead or in torpor, wait a few hours. If the bird starts shivering, that is a sign that it is starting to gradually wake itself up from torpor. If the bird does not gradually wake up, it has sadly passed away.
Do Hummingbirds Sleep Normally?
Scientists know that hummingbirds use torpor to survive colder nights when their high body temperature demands require lots of energy to maintain. However, what about summer nights when the temperatures are not as extreme?
Scientists are still not sure if hummingbirds experience lighter sleep patterns. There are variations in the state of torpor. During warmer nights or even during the day if they are feeling tired, hummingbirds will not lower their body temperatures by the same level that they do when it is cold.
How Do Hummingbirds Sleep When Migrating?
For such small creatures, hummingbirds have impressive powers of flight. Their yearly migrations can cross thousands of miles. While they are flying over land, hummingbirds can engage in their normal sleep patterns. However, when they are crossing over large bodies of water, hummingbirds can fly up to 20 hours without sleeping.
To prepare for this all-night flight, hummingbirds go into a feeding frenzy while on land. Even on a normal day, hummingbirds eat a lot, but before flying over large bodies of water they will double their body weight. A hummingbird that doesn’t have enough fat reserves sadly won’t survive the journey.
Hummingbirds do not sleep the same way that most birds do. Instead, they go into torpor, a state similar to hibernation where a hummingbird’s metabolism, body temperature, and normal body temperature lower drastically. Maintaining their normally high body temperatures and activity levels requires lots of energy and constant feeding, so this is the only way that hummingbirds can sleep.
Torpor can be dangerous to birds that do not feed enough to prepare for hibernation, but these small birds are tougher than they look and can even survive 20 hours of a migration flight without sleep if necessary. Torpor is yet another way that hummingbirds are fascinatingly unique.