Hibernation is a period of deep “sleep” practiced by many animals throughout winter. Mainly, the purpose of hibernation is to conserve vital calories when the food supply is short.
A hibernating animal will have a slower heart rate, lower body temperature, and slower metabolism while “sleeping.”
Do birds hibernate? No. As an alternative to hibernating, some migrate to warmer regions, while others enter a state of torpor.
There is, however, one bird that hibernates: the common poorwill.
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Why Don’t Birds Hibernate?
You will never see love birds hibernate, parrots hibernate, or pet birds hibernate. It’s not just because they are comfortable in your home — birds generally don’t hibernate, even in the wild!
Birds don’t hibernate in winter because they are naturally equipped with a means of “escape” — they simply fly away to warmer places.
Interestingly, the reason for migration is less about escaping the cold and more about following the food.
Though small, birds are tough — if they needed to, most could survive harsh weather conditions. However, all birds need to eat regularly to survive.
And that is why they fly away during winter: they search for warmer regions where bugs, seeds, and fruit are still aplenty.
Birds also don’t hibernate because they will be easy pickings for predators similarly desperate for food sources in the cold season. It’s simply safer for them to fly away.
However, not all birds are migratory, and those who stay behind must adapt. Some have evolved through centuries to enter torpor during this period.
What is Torpor?
Simply put, torpor is short-term hibernation. Like hibernation, it is characterized by a slower heartbeat, slower metabolism, and lower body temperature.
However, unlike hibernation, torpor can occur at any time of the year, not only during winter. It is also typically much shorter, sometimes only lasting a few hours up to a few days.
Though waking up out of torpor burns a lot of energy, the calories saved in those few hours drastically increase the likelihood of survival of birds.
Are There Any Bird Species That Enter Torpor?
Some bird species are known to enter torpor, including poorwills, nighthawks, oilbirds, hummingbirds, swifts, nightjars, mousebirds, and doves.
Interestingly, torpor is not a seasonal event for hummingbirds but rather a daily one: the species enters the state every night when they sleep and sometimes even during the day.
In that state, hummingbirds’ body temperatures fall by as much as 86°F (30°C). In other words, their body temperatures can reach 37.9°F (3.3°C)! This drastic drop allows them to save up to 50 times more energy than if they had stayed awake.
However, scientists have proven that hummingbirds actually have different levels of torpor, depending on the weather and the circumstances.
Scientists have also proven that there is no such thing as hummingbird hibernation. It is not true that hummingbirds hibernate in the winter — they are only in torpor.
How Do Birds Survive in the Cold?
How do birds survive in their environment when it is cold and there is little food available? For those that don’t migrate or enter torpor, here are a few other survival techniques noted by researchers:
1. Fluffy Feathers
Some birds grow extra feathers to help them stay warm in winter. Others fluff up their existing feathers to trap heat in and stay comfortable.
Others produce a specific type of oil that keeps their feathers waterproof and helps them avoid getting wet and extra cold.
2. Caching Food
Like squirrels creating caches of nuts for winter, birds also hide away seeds, nuts, and other potential food in secret places.
Black-Capped Chickadees are known for their incredible recall of hundreds of hiding spots filled with little food stashes!
3. Hot Feet
Despite looking like feeble twigs, birds’ legs and feet are designed to help them stay warm during winter. In particular, the birds’ heart regularly pumps warm blood through arteries that pass through their legs to ensure they don’t get too cold!
Frequently Asked Questions
1. What do birds do in winter?
Birds either migrate or stay put in winter, both options with their own sets of challenges.
Migratory birds need to develop stamina and strength for a long, arduous journey, usually having to double their weight in the fall.
Birds that stay put tend to regularly enter states of torpor or inactivity, cache food, and adapt other strategies, such as shivering to keep warm and fluffing up their feathers.
2. Do birds hibernate or migrate?
Some but not all birds migrate in the winter. However, what’s for sure is that the common poorwill is the only bird to hibernate!
3. Which bird hibernates?
There is only one name on the hibernating bird list: the common poorwill from the nightjar family.
Common poorwill hibernation has long been observed by the Hopi people indigenous to Arizona. It prompted them to give the bird the nickname holchko or “the sleeping one.”
The species has been observed to hibernate for days or weeks, maintaining a body temperature of 41°F (5°C) with a respiratory rate of only 10% of their standard.
Do birds hibernate in the winter? No, they do not. Therefore, birds in your yard during these months of low food supply would appreciate any help you can offer them.
If you can, set up bird feeders full of seeds and other protein-packed food, plus bowls of drinking water for birds in the winter. If you have space in your garden, birds will also enjoy birdhouses and other shelters you can provide.
After all, we can all empathize: no one likes being cold and hungry.
George and I became friends after a birdwatching trip with our new group. And we have been enjoying every adventure together. When he told me the idea of establishing a site that shares our experiences and fun, I immediately agreed. After trials and errors, here we have Thayerbirding.