Barred Owl
By Janice Bergstrom, 2008
This article appeared in Jan's nature column in the Hutchinson Leader.
~~~~~~A few days ago, I noticed a barred owl perched atop my wood duck house located
in the middle of a marsh. Barred owls are primarily nocturnal, but will
occasionally be seen hunting during the day. He was more than likely very
hungry; possibly one of last year's young who hasn't really figured out the
program yet. He stayed for about an hour, diligently searching the dried
vegetation for a meal. Like a scene from "The Exorcist", he rotated his head
270 degrees in search of prey.
~~~~~~Composed mostly of feathers, and weighing only a pound and a half, barred owls
are highly specialized for the task at hand. Owls rely keenly on their
eyesight for locating prey, but there is no room in their skull for eye
muscles; thus the need for extreme head rotation. Nature has given them one
extra vertebra to allow for this flexibility.
~~~~~~Being quiet as a mouse could be fatal, if there is a barred owl around. Their
hearing is so sensitive, they can hear animals under snow. Their right ear is
higher than the left, which helps it pinpoint the source of a sound. Their
facial disks allow it to magnify sound pressure tenfold. Once the location of
prey is determined, it swoops down. Their wings, which span 42", have special
fringes on the leading edge, which muffle the sound of air passing over them.
Breaking through the snow, they grasp their prey in razor sharp talons. It's
hooked beak tears off chunks, which are gobbled down without chewing. They
have no crop for food storage, and must therefore expel undigested bones and
fur in pellet form through regurgitation about 6 hours after eating. These
pellets can be found underneath nesting trees, providing scientists with huge
amounts of data on the diet of these lovely birds of prey.
Barred owls, Strix varia, are one of twelve owl species found in Minnesota.
They belong to the order Strigiformes, all of which have fixed eye sockets.
Their back is grayish brown, and they have a light underside with dark streaks.
They are Minnesota's only typical owl that has dark eyes.
Barred Owls eat mostly mice, but also feed on rabbits, chipmunks, foxes, and
possums. They occasionally wade into water in order to capture frogs or
crayfish. A diet heavy in crayfish may cause its breast feather to become
tinged with pink.
~~~~~~Preferring old growth deciduous forests and heavily wooded swamps for roosting
and nesting, barred owls are often associated with red shouldered hawks.
Hunting occurs in more open areas.
Their territories are 1/3 to 1 ½ square miles. The familiar "who cooks for
you, who cooks for you all" call warns other owls that the territory is
occupied. It is common for several owls to meet near common boundaries and
battle over exact lines by using a series of cackles, caws and hoots that sound
like maniacal laughter. I heard this often at my house, bringing visions of a
serial killer convention to mind. It is an experience once heard, never
forgotten!
~~~~~~Barred owls form permanent pair bonds, but stay together only for breeding and
raising their young. Courtship begins in winter. The nesting site is a large
cavity in a tree, oftentimes created by a pileated woodpecker, or an old hawk
or crow nest. Two to 4 eggs are laid in March. After about 28 days, the eggs
hatch. The young will leave the nest in approximately one month, but continue
to return to it for two more weeks. If nesting is successful, the pair will
return to the same site year after year.
The great horned owl is the biggest predator of the barred owl. Hawks,
raccoons, and cats will also kill them. They seem to be adapting to human
expansions, and their range is expanding. It is illegal to capture or kill
them, as they are protected under federal law.
~~~~~~Barred owls can occasionally be attracted to a nesting box.
Boxes need to be in place by September.
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