Birds are fascinating creatures. They have many different habits that make them unique from other animals, and one of those is the way they sleep.
Birds are so diverse in their sleeping habits that it has been difficult for scientists to come up with a general answer as to how they do it! In this blog post, we will discuss the fascinating habits of birds and delve into whether or not birds sleep in nests at night.
Do Birds Sleep In Nests?
A common misconception is that birds sleep in their nests. But as it turns out, this isn’t the case for any bird species! Birds do not sleep in their nests.
Nests serve only two purposes – to provide safety and warmth for eggs when they are first laid or young chicks as they grow up. But some birds do sleep while they’re sitting on their eggs to keep them warm and safe.
Where do birds sleep at night?
After a long day’s work of foraging for food, withstanding the harsh elements and while avoiding predators. Birds need to rest and sleep. Since sleeping can make them vulnerable, they must choose a location that prevents them from being eaten by a nocturnal beast looking for a meal.
Perchers and Cavity Sleepers
Sleeping habits for the majority of bird species can be broken down into two types, perchers and cavity sleepers. Both take advantage of different resources for their nightly slumber.
Perch-sleepers will rest on tree branches or twigs behind dense foliage or camouflage themselves next to the trunk of a tree. It is important to pick a location that shelters them from wind and rain and predators.
While cavity sleepers like woodpeckers, bluebirds, chickadees, and titmice will seek out tree holes for safety and warmth.
How do birds sleep without falling out of the tree?
Cavity sleepers of course are nestled in a small cavity within a tree so they won’t fall out, but what about those perch-sleepers. We need to talk a little about biology to understand perching birds (passerines or Passeriformes).
Perching birds are the birds you see in your backyard at the feeders with the exceptions of doves, woodpeckers, and hummingbirds. (Hummingbirds do perch and hold on to twigs but are not part of the passerine group).
Vice Like Feet
Perching birds have specially designed feet. They possess two thin flexor tendons which run down their tarsus bone (Toes). When they land the bird’s weight causes an involuntary reflex that tightens the tendons and locks their feet around the branch, twig, or other objects.
When the bird falls asleep, its legs remain in a locked position. This allows it to hang from trees without falling out of them. When they wake and fly off, the leg straightens which causes the tendon to relax and unlock their feet.
When Do Birds Sleep: Diurnal and Nocturnal?
Birds are divided into two groups: Diurnal and Nocturnal. Diurnal birds are awake during the day and sleep when the sun goes down.
Nocturnal birds are the opposite, they wake when the sun goes down and head off to sleep when the sun rises. The most famous nocturnal bird is the owl, whooooo, the owl.
How do birds sleep?
Once the bird is safely perched or resting in the cavity of a tree or structure, they will fluff up their down feathers creating air pockets for insulation. They will turn their head toward the back and tuck their beak in the feathers to help keep warm. Sometimes they will lift one leg up into the feathers to help prevent body heat loss. Hummingbirds are the ultimate sleepers.
(Look here for a description of Hummingbirds’ “torpor” sleep.)
Positions
According to a zoology professor at Hampshire College, bird species typically sleep in one of four ways. The first is diurnal horizontal rest, which describes how many species sleep while they are perched on a branch or even upright.
The second is diurnal vertical rest, which features birds sleeping while they are sitting on a perch with their heads tucked under their tail feathers. This position offers protection from the sun, rain, and predators.
Another type of sleep posture is nocturnal horizontal rest, in which birds sleep while flat on their sides or backs with their eyes open. Since many birds sleep in this position, it’s believed that they are able to see their surroundings through their half-closed eyelids and stay alert for predators.
The last is nocturnal vertical rest, which is when a bird sleeps while standing on one leg on a perch or branch.
Sleep Cycles
Like humans, birds sleep in two segments: REM and non-REM sleep. Rapid eye movement (REM) sleep is when we experience our dreams while we are sleeping. This stage of sleep can be very restorative to tired and stressed-out birds.
This stage of sleep is when our muscles are relaxed and the body rests. The process of REM can be broken down into three stages: 1) A light sleep with one eye open, 2) deeper sleep that reduces muscle tone 3) Stage in which brain activity is similar to wakefulness.
Sleep With One Eye Open
I am sure you have heard the term “sleeping with one eye open”. Well, birds do this while they sleep. This process is known as Unihemispheric slow-wave sleep (USWS). Birds have the ability to allow one side of their brain to sleep while the other side is alert for possible dangers. Depending on the threat level, birds can control how much USWS they use by the amount their eye is open or closed.
How Do Birds Stay Safe From Predators While Sleeping?
Unihemispheric slow-wave sleep (USWS)
USWS is one tool birds utilize to stay safe while they sleep. The ability to “sleep with one eye open” allows for constant alertness for predators.
Flocking Together To Keep Warm and Safe
Some species of birds will also sleep in flocks (swallows, cardinals, bluebirds, and nuthatches) this allows the birds to stay warm at night and provides a “safety in numbers” concept.
Flocking together at night is not always the constant. Some species like the cardinals only sleep in flocks during the colder months but not during the breeding season.
Camouflage
These are just a few ways birds stay safe while they are sleeping. Another is the use of camouflage. Birds will hide within dense brush or naturally (by feather markings) to their surroundings. Some bird species are able to camouflage themselves with their surroundings so well that they go undetected by predators. “Their camouflaging skills remind me of Harry Potter’s invisibility cloak.
“Check out “Images Show How Good Bird Camouflage Can Be”
What About The Bird That Claims to Sleep While Flying?
It is true, swifts (Apus apus) do sleep in flight. However, they are not the only birds that can accomplish this amazing feat.
Swifts are a species of migrating bird that spends their non-breeding season in tropical Africa and lives in Europe over the winter. This species of tiny bird has the longest migration of any bird with some migrating across the Atlantic ocean in three days!
They accomplish this seemingly impossible feat by soaring through thermal currents and catching updrafts that propel them high into the air while they sleep on their long journey.
This form of USWS allows them to conserve energy and rest while flying. Swifts will fly for a few minutes and glide in what scientists refer to as “sleep gliding” before catching another updraft and soaring again.
What Seasons and Weather Changes
Birds are very adaptable to changing seasons and varying weather. Some species will migrate for the winter to avoid the colder seasons, while others (resident birds) will sleep in spaces that will provide the most protection from the elements and keep them warm.
Migrants
There is a wide variety of birds and people who will travel south for the winter. Some of these migratory birds are rose-breasted grosbeak, white-crowned sparrow, and the best-known migrator of all, the hummingbird.
Resident Birds
Resident birds sleep in a variety of ways during the winter or cold months. Birds such as chickadees, titmice, wrens, and woodpeckers will settle into tree hollows and tree cavities to stay warm and shelter from the elements.
Goldfinches have been known to burrow in the snow to take advantage of the snow’s natural insulation. They also can roost with other goldfinches in coniferous (trees that have cones).
Nuthatches will look for old woodpecker holes and other tree cavities. Sometimes they will be found sleeping in large numbers, even on top of each other.
The After Knowledge
At the start of this article, you were wondering if birds sleep in nests. Now you know birds do not sleep in nests (unless they are incubating eggs or keeping hatchlings warm). Birds can be found sleeping in a variety of locations, whether it is hanging onto a tree limb, hiding in thick brush, or sleeping in the cavity of a tree.
It’s no surprise that birds have evolved a variety of ways to stay safe while they sleep. From sleeping in flocks for warmth and safety, camouflaging themselves so predators can’t find them, or migrating when the seasons change – these are just some examples of how nature has provided our feathered friends with all the tools they need to survive.