Do Any Species of Birds Hibernate?

Last Updated on Jan 23 2023

As most people know, some unique animals can regulate their heart rates during winter to conserve energy. This fascinating phenomenon is called hibernation, and some animals, primarily mammals, enter the state of hibernation to survive cruel winter conditions without much food or water supplies.

In this article, we will research if hibernation is possible for birds and, if so, how they can achieve that and why. We’ll give you a hint; birds go under a state similar to hibernation, called torpor. Many birds can use torpor when needed. Some of the most familiar birds are the chickadees, doves, nighthawk, roadrunner, and in the text below, we’ll mention a specific bird that can hibernate for a few weeks or even months.

Which animals hibernate?

Hibernation is the ability to go to deep sleep, almost through the entire winter, and conserve energy. Once an animal enters the state of hibernation, it can stay in that state sometimes for months. One animal that genuinely sets the record for most time spent in hibernation is the groundhog, at 150 days in hibernation.

Other animals that experience this are bears, bats, snakes, squirrels, turtles, frogs, insects, and others. This state is needed for animals unable to feed during winter or that cannot survive in winter conditions when the temperatures get very low. Their metabolism and heart rate slow down drastically, which allows them to store body fat that will keep their bodies protected in this state of lethargy during the entire winter.

Birds have a similar deep sleep state that they use; it is called torpor. The only difference between torpor and hibernation is the duration of the state itself. While mammals can hibernate for the entire winter, birds stay in torpor for hours or one whole night. The state of torpor is not as deep as hibernation, animals that are in hibernation have a state similar to sleep, and they cannot perform other actions while in this state. In contrast, birds in the state of torpor can move, feed or sometimes even interact in social situations with other birds.

Which birds go into torpor?

A few known species of birds use torpor to survive winter. Birds will use torpor when the temperatures get dangerously low, so they go to this state of deep sleep to buy themselves some time before migrating to warmer regions. Birds that depend on eating insects will also use torpor, as most insects die off during winter, making it harder for birds to have a consistent food source. Some of them are doves, hummingbirds, nighthawks, roadrunners, titmice, sunbirds, chickadees, and more. Smaller species of owls will also use torpor during winter when the nights get too cold for them.

Hummingbirds, for example, can lower their body temperature rapidly, trying to match the outside temperatures. They are one of the smallest bird species, and being so small, they lack the isolating layer of feathers. Even when they are not using torpor, their conditions are sometimes tough to meet and maintain. When in torpor, the hummingbird slows down their heart rate significantly. They stay in this state from 20 minutes to a whole hour, and after waking up, they recover and fly away.

One bird can hibernate genuinely, similar to mammals, and it is the common poorwill. This fascinating bird is the only known species to go into torpor or hibernation for more than one day, and it can usually last for even weeks or months. This remarkable ability is thought to be an evolutionary advantage, so they don’t have to leave their surroundings and migrate like other birds. The common poorwill doesn’t always use torpor; their hibernating patterns aren’t as consistent as those seen in mammals. If the conditions are not as bad and cruel during winter, the common poorwill will hibernate for a much shorter time or won’t hibernate at all.

Some birds have been known to enter torpor but still be able to walk and change their positions or even feed when given the opportunity. They sometimes exhibit social behavior when in torpor, and other birds come their way.

What happens after the bird wakes up?

After waking up, the bird will need to recover and regain its strength. It will begin by shaking its body to bring some blood flow and raise its body temperature. Before continuing with its life, as usual, the bird will have to find a rich food source; it has lost a lot of energy and needs to regain strength as soon as possible.

What are the downsides of torpor?

As much as torpor can be helpful for birds or come as a lifesaver at certain times, it does have its downsides. Once the bird becomes torpid, its reflexes slow down drastically; the bird is slow and unaware of the surroundings. The bird becomes easy prey to any predator that may appear. The state of torpor makes the bird unprotected, vulnerable, and unable to defend itself.

Another downside to torpor is that the birds sometimes wake up to find themselves still facing rough and cruel weather because it lasts so short. If the conditions in the environment are still the same as before, some birds can face death. Since they just came back from their energy-saving nap, they need some time to recover, and if there are no food sources to help them gain energy or the temperature of their body gets too low, that can be a deadly scenario.

Conclusion

While a few species have a state similar to hibernation, called torpor, there are just one known species so far that truly hibernates, similar to mammals. The common poorwill stays in hibernation for a couple of months if needed, which is thought to be a new, evolutionary skill. 

These abilities are remarkable and fascinating to own; they are beneficial and can save the lives of many birds that cannot survive winter. These birds go into torpor before migrating, and this way survive in even the most challenging conditions they are in.

In this article, you can learn about one of the many extraordinary abilities birds own. These incredible creatures keep surprising people with their unique adapting skills, as some birds can prolong or even cancel their migrating plans for the year by using torpor.

Featured Image Credit: Gerrit Lammers, Shutterstock