Common Nighthawk taking a snooze on a wire. Photo by Joey Herron.

Do birds sleep?

Have you ever wondered what happens to birds at night? Where do they go? What do they do? Do birds really sleep?
 
The answer is yes…but it’s a little more complicated than that.  Birds have several techniques for when they need to get a little shut-eye. Check out some of these below!
A juvenile Red-Tailed Hawk catches some zzzzz.... Photo by Morgan Terrinoni.

A juvenile Red-Tailed Hawk catches some zzzzz…. Photo by Morgan Terrinoni.

Nocturnal birds like this Barred Owl are more active at night. Photo by Tony Joyce.

Nocturnal birds like this Barred Owl are more active at night. Photo by Tony Joyce.

 

 

 

 

 

 

 

 

 

Day flyer or night rider?

If you’ve ever seen an owl, then you may know that some birds prefer to fly primarily at night. Nocturnal birds, like owls and nighthawks, wake up as the sun sets and hunt at night. During the daytime, they find a safe place and close their eyes to block out the light. By contrast, most birds are diurnal, meaning they’re awake during the day and asleep at night. These species will find something to perch on, like a branch or a windowsill, for the night. Then, the bird will fluff out its down feathers, turn its head around, tuck its beak into its back feathers, and pull one leg up to its belly before falling asleep. Sounds uncomfortable, right?

Actually, it’s quite warm for the snoozing bird. Down feathers, the short fluffy feathers under the sleek outer ones, hold in heat. The bare parts of the bird (the beak and the legs) are tucked in to keep warm under the thick blanket of feathers as temperatures drop for the night.

Won’t birds fall off their perch as they sleep?

Balancing act. A Northern Rough-winged Swallow takes a nap. Photo by Kevin McGowan.

Balancing act. A Northern Rough-winged Swallow takes a nap. Photo by Kevin McGowan.

Actually, it is very unlikely that roosting birds will fall from their perch. When the bird places weight on its feet, the muscles in the leg force the tendons of the feet to tighten, keeping the foot closed. This gives the bird a vice-like grip around any branch it may be resting on, so the bird doesn’t slip off.

Not all birds sleep on branches however. Waterfowl and shorebirds sleep near the water. Ducks often stand at the water’s edge or on a partially submerged stick or rock and tuck one foot into their body, much like birds do on perches. Wherever birds can get a good footing, they tuck themselves in for a rest. Chimney Swifts have been documented resting when clinging to the insides of chimneys!

No rest for the feathered!

With so much to worry about— the cold, predators, noisy neighbors— how do birds get a good night’s rest?

Well…they don’t, at least not in the way humans think of a good night’s sleep. Unless they are in a state of torpor, birds tend to sleep in small snatches until startled awake either by a predatory threat, neighbor, or cold conditions.

Redhead pair asleep on the water. Photo by Kevin McGowan.

Redhead pair asleep on the water. Photo by Kevin McGowan.

Some can even sleep with one eye open, as half of their brain is alert while the other is asleep. This is called unihemispheric slow-wave sleep (USWS) and it allows the sleeping bird to spring into action quickly from rest if a threat approaches while still being able to satisfactorily rest if no threat arises. Ducks and waterfowl are particularly good at this, though other birds such as Peregrine Falcons and Eurasian Blackbirds can do this as well. Species that use this adaptation may even be able to sleep while flying!

Migrating birds may also rely on USWS to rest. The long migration flights of many species don’t allow for many chances to stop and rest. But a bird using USWS could both sleep and navigate at the same time. There is evidence that the Alpine Swift can fly non-stop for 200 days, sleeping while in flight!

Kind of makes you wish you could sleep like a bird, doesn’t it?

 

 

A sleepy young Great Horned Owl. Photo by Anne Elliott.

A sleepy young Great Horned Owl. Photo by Anne Elliott.

Going Further

22 Comments

  1. Pingback: Bird Biology : Cornell Lab of Ornithology: BirdSleuth K-12

  2.  by  Gretchen

    Wow! Very interesting. Also love Merlin that I just got the app for. Great at helping me identify birds!!!

  3.  by  Dexter

    I love all the article from the Cornell Lab! I’ve been following the live bird feeds the past couple months and can’t keep my eyes off of them beautiful birds! It’s almost spring time in Alaska and I’m ready and set for all the song sounding birds to arrive and fill my feeders with color as I enjoy every morning with my window slightly open listening to the birds with my hot cup of tea.
    I’ve also built a American Robin Next Box and installed it in the area. I got the nest box blue print from the Cornell website as well. Very resourceful website and am a new loving follower.

  4.  by  Tiffany

    Wow thanks! Now I know about birds and stuff! (I wanted to see Quail’s the most and learn about them!)

  5.  by  Janice Stone

    I have a brown thrashers nest in a very thorney bush in field.Mom is crouched down on her eggs with dad not far away

  6.  by  Steven Verdick

    Great insight, thanks! With all the problems that we encounter during a normal day, it is amazing just to watch birds in action. We have 2 separate nests going up right now. One under the awning in our front porch & the other in our outside carport. It is really something to watch them build their nest, lay their eggs (an absolute must if you have never seen this) & then for the babies to hatch, be fed, & finally the mom kicking out the babies to fly! Initially they don’t fly but are on the ground walking. They finally start flying & then the process starts again. So cool!!! Feel sorry for people that have never experienced this. Life is too short. Do something besides watch T.V., play video games, etc. Experience real life.

  7.  by  Trisha

    Love the birds that have discovered my yard since I installed a little fountain, BUT a particular black phoebe has chosen to roost overnight on the 16′ high support chain for my front porch light, leaving ugly deposits on my front steps every morning. How can I get this daily resident to find a better roost?? Thanks for any ideas!

  8.  by  James

    I have a pet bird, they’re budgies, sometimes they’ll sleep with their heads backwards.

  9.  by  Mitch Rezman

    Birds have no muscles in their legs only 2 flexor tendons in each leg. the clamping toe/talon thing comes when a bird changes the angle of it’s ankle

  10.  by  sergio reyes castellanos

    Thank you por sharing this important information. My grand daughter five years old enjoy it.

  11.  by  WANDA MYERS

    so all my birds when i turn off thier lights and tell them night they sleep all night? they do not wake up and play during the night?

  12.  by  Edward Carlin

    There are two Carolina Wrens on my porch. One’s in a corner and the other’s on an abandoned wasp nest. Haven’t seen any owls in the last month. Do they slow down when it gets colder? Thanks.

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