The tiny screech owl is frequently an unknown neighbor

StoryImage( ‘/Images/Story//Auto-img-119326972620758.jpg’, ‘Photo by Dr. Robert A. Hedeen’, ‘The screech owl is common throughout the Rock River Valley.‘);

Editor’s note: Long-time outdoors columnist Dr. Robert A. Hedeen passed away Oct. 4. Prior to his passing, he had compiled a number of columns for publication. Those columns will appear in print until all have been published.

The wailing cry in the night that disturbed Henry David Thoreau in his cabin by Walden Pond came from a screech owl. Thoreau describes the wailing in his classic Walden as, “A lost soul crying: O-o-o-o that I had never been bor-r-r-rn.” It also utters other sounds from time to time, including screeches, whistles, hoots and barks.

The screech owl is a small owl that is found throughout North America, and is termed by biologists to be a polymorphic (many forms) species, in that red and gray individuals are found throughout its range. Red, or rufous, individuals make up about one-third of all screech owls, with a majority of this type occurring in the East. Many birds change color as the seasons change, but not this owl, and the coloration of the males and females is similar. Owlets from the same brood may be either red or gray.

This owl is listed as being as “fairly common” at the Severson Dells Forest Preserve, and undoubtedly occurs throughout the Rock River Valley. It may be distinguished from other small owls by its distinctive ear tufts (it is sometimes called the little horned owl). It is common in Western Europe, and I recall in France it is called Le hibou petite-duc (the small-duke owl).

Similar to other owls, this little fellow is nocturnal, and rarely leaves its nest in the rot cavities of trees during the day and is rarely seen around our homes. They are year-round residents, and on cold winter days they may be seen sunning themselves in the doorways of their retreats. It ventures forth at night to hunt voraciously.

While a screech owl rarely ventures forth during daylight hours, we will hear about it as other birds will issue loud warning cries. Song birds fear owls and will issue warnings when owls of any type are in the vicinity. The primary diet of this owl consists of rodents and insects, but, on occasion, they will feed on crayfish, earthworms and other birds. The pestiferous starling frequently ends up as the owl’s dinner, as, for some unknown reason, it has the deleterious habit of attempting to take over a screech owl nest and occupy it to raise its young. Starlings are not known to be too smart.

When food is plentiful, the screecher may stuff itself. Two screech owls in captivity were observed to eat from one-quarter to one-third of their total body weight each night (these little fellows have been known to clean out an infestation of mice in a very short time). Being frugal and wise, they were occasionally noted to skip a night’s feeding to store food for a time when the victuals are not so plentiful.

Screech owls are usually monogamous and remain bonded for life. Some, but not all, males have a roving eye and may mate with two different females. The second female feels short-changed when the male does not set up separate housekeeping with her, and she will try to evict the first mated female to lay her own eggs in the nest, and then proceed to incubate both clutches.

Owls are arguably one of the most beneficial birds we have, and their presence about our property should be encouraged. If an inspection of your property reveals there are no rot cavities in trees large enough to accommodate a screech owl, you might try erecting a rather large bird house with an opening of at least 3 inches in diameter in a secluded area. The odds are it will soon be found to be occupied by this interesting and beneficial bird.

Dr. Robert Hedeen was a former resident of Maryland’s eastern shore and resided in the Chicago area from 1960 to 1971. He was a retired professor emeritus of biological sciences in the University of Maryland system. He had published more than 30 scientific papers, written numerous magazine articles, and was the author of two books about the natural history of the Chesapeake Bay.

from the Oct. 24-30, 2007, issue

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