My wife was looking through a new bird book yesterday and found the statement that Chimney Swifts spend so much time in the air that they even sleep in flight.
Can any dopers shed light on this statement. I can’t imagine birds sleeping in flight and staying in flight.
GaryM
I’m a birdwatcher, and I have heard this, too. However, I think it must be classed as an ornithological Urban Myth, similar to the one that says, “birds drown during hurricanes because their nostrils fill up with water.”
At night, like other diurnal birds, swifts go into their nests and, presumably, sleep. I don’t see how any organic being like a bird could keep making the incredibly complex controlled series of large muscle movements and navigation decisions (“over or under the power lines? Through the tree or around the tree?”) that flying entails while being asleep.
I think we’re looking at a holdover UL from earlier eras. It may have looked to observers as though a swift was asleep because it seemed to be flying aimlessly, not catching insects. But a swift’s mouth can work much faster than the human eye can catch, especially when it’s 500 feet up in the air, so swifts can be catching tiny insects like mosquitos and you wouldn’t necessarily be able to spot it.
Also, this factoid might have sprung from the swift’s migration habits, which may take it far out over water, where presumably there’s nowhere to perch and sleep. Therefore, it was assumed that they must sleep while they’re flying. However, I think it’s possible that birds on migration have different biorhythms, which would mean that they don’t need to sleep as such. Some warblers spend literally days out over the ocean on their way south, or north. I don’t think we know enough about the physiology of migrating birds to determine whether or not they actually “sleep” while they’re flying.
Is the book a serious field guide or one of those “All About Your Feathered Friends” books?
DDG,
It didn’t seem right to me. This is in the “Audubon Backyard Birdwatcher” copyright 1999. Just bought the book last week at Sam’s Club. I’d expect anything in an Audubon book to be the straight dope.
I can drive and sleep at the same time with some success, but that’s only in two dimensions!
GaryM