About us: We own the Wild Birds Unlimited nature shop in East Lansing, Michigan,
a store that provides a wide variety of supplies to help you enjoy the birdwatching hobby.

This blog was created to answer frequently asked questions & to share nature stories and photographs.
To contribute, email me at bloubird@gmail.com.

Wednesday, September 15, 2010

Do Birds Sleep Standing Up?

I'm interested in where birds go to sleep and if they ever lay down? Cheryl~Charlotte, Michigan

sleeping birdImage by looseends via FlickrBirds always have to be alert for predators, ready to dart away at a moment's notice. Positions can vary but the best that many birds can hope for are short little bursts of sleep. .

Sleeping habits can also change with the seasons. Birds tend to sleep in the same areas they inhabit during the day. For instance, territorial birds often sleep on their nests, during the breeding season but now in the fall might sleep communally in large roosts. Water birds will sleep sitting or standing on the shore, or in the water or on predator-free islands. Tree-dwellers prefer to sleep in trees or dense shrubs out of a predator’s reach.

I have a lot of backyard birds that like to sleep in the pine trees near the feeding stations. As dusk approaches there is a feeding frenzy. The goldfinches at my house sometimes stay too long. I watch them feeding furiously and then see them look up and notice sun went down. Some find shelter quickly in nearby bushes while others have been known to spend the night on a feeder or if it's windy, huddled in a corner close to the house.

When birds are tired, they scrunch down to sleep because that automatically makes the toes grip their perch and stay locked. In the legs of tree-dwelling birds, the tendons from certain muscles extend down the leg behind the ankle to attach to the tips of the toes and when their knees bend, the tendons are pulled taut, making the toes on their feet clench.

Sleeping ducksImage via WikipediaSome birds can also sleep with only half a brain and one eye open, always on the lookout for danger. Keeping one half of the brain at rest is called unihemispheric slow-wave sleep (USWS).

Along with finding a safe place from predators to catch a few winks, birds also need protection from the weather. Birds fluff their feathers to create many tiny air spaces that drastically reduce heat loss (the same principle that makes down jackets so warm in winter) and bury naked body parts into their feathers. This is why many birds pillow their head on their shoulder with their bill tucked among downy back plumage and have one leg held tightly up against the body.

Birds can also begin a constant shivering called thermogenosis to produce heat five times that of their normal rate, helping them to maintain an amazingly high body temperature. Scientists have found that some birds like chickadees go even one step further to survive the cold winters. The birds go into a nocturnal torpor to conserve energy. Torpor is a kind of deep sleep accompanied by drastically lowered body temperature, heart rate, and breathing. The result is a controlled hypothermia that can save a bird up to 20% of its energy. (Hibernation is defined as a sustained state of torpor.)

So remember, when you snuggle safely under the covers tonight, it might not be as easy as you thought to be free as a bird.

1. Half-awake to the risk of predation
2. Cornell Lab of Ornithology Handbook of Bird Biology
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Terry said...

Fascinating, I never thought about this.

Wild Birds Unlimited Mid-Michigan said...

I'm glad you liked the post. Keep your questions coming everyone.

Tina Coruth said...

I never heard of unihemispheric slow-wave sleep (USWS). That is fascinating! I enjoyed reading your article.

Wild Birds Unlimited Mid-Michigan said...

Hello, Birds have overcome the problem of sleeping in risky situations by developing the ability to sleep with one eye open and one hemisphere of the brain awake.

When you walk by ducks tucked up for a nap you can see that most have one eye open. They'll be ready for any approaching predator and still be taking a nap.

Birds are fascinating and have lots of adaptations that have allowed them to survive for millions of years.

Thanks for the comments, Sarah