Nature Bulletin No. 445-A   February 19, 1972
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

****:SLEEPING BIRDS

Each winter, a few years ago, several thousand crows, roosted in the big 
woods near our house. In daytime they spread out over the countryside 
to find food but each evening, about sundown, they came streaming 
back in a continuous parade that took almost an hour to pass. In flocks 
of dozens or hundreds with scattered birds between, they flew the same 
route every day. In downstate Illinois, similar flocks roost in overgrown 
hedgerows of osage orange, isolated groves of timber, or on willow 
grown islands in large rivers.

A much smaller flock still roosts the year-round in our woods. 
Ordinarily they slip in a little before dusk and settle down quietly but 
occasionally there is a hullabaloo as if they were squabbling over a 
favorite perch occupied by some newcomers. Just before dawn, one old 
bird we call "the bugler" caws three times. A minute or two later he 
repeats it. Then, one by one, drowsy voices of other crows are heard -- 
much like human sleepyheads in the morning. Sometimes an alarm call 
is heard during the night followed by a general clamor as if the flock 
had been disturbed by a marauding owl, weasel or raccoon. Crows are 
very wary and, like most birds, light sleepers.

Very little has been written about the sleeping habits of birds except in 
a general way but apparently, like people and other warm-blooded 
animals, after they are tired and full of food they want to sleep. When 
they wake they yawn stretch, and seem refreshed but hungry again. 
Further, most birds cannot see well at night. Only a few, like the owls, 
have large eyes specially adapted for night vision. English sparrows 
driven at night from their roosts in our garage or among thick ivy on our 
house, fly off in a blind blundering panic.

Going to bed is a serious business for small birds and frequently a 
matter of life or death. The roost selected is usually sheltered from the 
wind, dry as possible, and out of reach of their enemies. Although there 
are many exceptions, most birds show a preference for the type of place 
in which they were born. So far as is known, the many kinds that nest in 
trees or shrubs generally one of these perching birds lights on a twig or 
branch and squats, its toes automatically lock tight and it cannot fall 
while asleep.

Hole nesters such as woodpeckers, chickadees, nuthatches and screech 
owls, usually sleep in tree cavities. The bobwhite quail, pheasant, 
prairie chicken, meadow lark and other ground nesters sleep on or near 
the ground. At night a covey of quail forms a ring with all heads 
pointing outward. If attacked, they explode in all directions with a great 
whir of wings. In winter, quail and grouse sometimes dive into and 
sleep completely buried in a snowdrift but if a hard crust is formed by 
freezing rain they perish.

Wild turkeys spend the night high in the tallest trees of some secluded 
woodland. During their migrations we see wild ducks and geese 
sleeping in dense "rafts" on the open water of lakes and sloughs; also 
along the shores, or even on ice, where they stand first on one foot and 
then the other. Like most birds, they appear to tuck their heads under 
their wings while asleep but, actually, it is under a tuff of feathers that 
drapes over each shoulder. Owls, buzzards, hawks and some other 
merely hunch their heads down between their shoulders. Starlings and 
grackles gather in great flocks which, every evening before they go to 
sleep, make an uproar like children on their first night in a summer 
camp.

Many birds "talk" in their sleep and some even sing on moonlit nights.