Posts Tagged ‘echo location’

Halloween and Barn Owls

October 31, 2007

Happy Halloween to all. It is that wonderful pagan holiday where grown-up people can dress up and pretend to be something they are not. It is also the time when witches, owls, and ravens rule the night.

Ravens and owls have bad reputations the rest of the year. Edward Howe Forbush thought that unfair. He was the author of Birds of Massachusetts and Other New England States, a three volume work first published shortly after Mr. Forbush died in 1929. Here is what he had to say in defense of Barn Owls:

Since the dawn of history, owls have been the pitiable victims of ignorance and superstition. Hated, despised, and feared by many peoples, only their nocturnal habits have enabled them to survive in company with civilized man. In the minds of mankind they have leagued with witches and malignant evil spirits, or even have been believed to personify the Evil One. They have been regarded as precursors of sorrow and death, and some savage tribes have been so fixed in the belief that a man will die if an owl alights on the roof of his dwelling that, it is said, some Indians having seen the owl on the roof-tree have pined away and died. Among these eerie birds, the Barn Owl has been the victim of the greatest share of obloquy and persecution, owing to its sinister appearance, its weird night cries, its habit of haunting dismal swamps and dank quagmires, where an incautious step may precipitate the investigator into malodorous filth or sucking quicksands, and its tendency to frequent the neighborhood of man’s dwellings, especially unoccupied buildings and ghostly ruins. Doubtless the Barn Owl is responsible for some of the stories of haunted houses which have been current through the centuries. When divested by science of its atmosphere of malign mystery, however, this owl is seen to be not only harmless but a benefactor to mankind and a very interesting fowl that will well repay close study.

Indeed. For instance, that weird looking facial ruff appears designed to focus sound waves, magnifying them before delivery to the Barn Owl’s asymmetrical ears. Aware of minute differences in the time the sound waves arrive at each ear, the owl is capable of precisely determining the locus of the sound. A sound coming from above will seem to the owl to be slightly louder in the ear with the higher opening. A sound from the left will seem slightly louder in the ear with the left-most opening. A sound equal in both ears is straight ahead. In experiments, Barn Owls successfully hunt in absolute darkness even though in the wild there is usually at least some night illumination.

And like all owls, they hunt soundlessly. The leading edges of the first primary wing feathers are serrated which disrupts the flow of air over the wings which silences the vortex noise created by air flowing over a smooth surface.

But it is Halloween, so – if you want – you can be afraid of Barn Owls; but for tonight only.

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For More on Barn Owls, see “Toe Dusting.”

Want to know how to identify Barn Owls?  Here is how if you can see the bird; here is how if it is dark and you can only hear it.

Here is a piece on the Wisdom of Owls.

For more on the delightful E.H. Forbush, see our post about Belted Kingfishers.

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UPDATE – APRIL 3, 2010

Follow this link to a live web cam of a Barn Owl tending to brand new babies.


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