Walkers on the Juneau Airport dike trail have been treated to recent sightings of Great Horned Owls in bare cottonwood trees beside the trail.
Laurie Ferguson Craig, a daily trail walker, reports seeing a single owl on several occasions. One sighting was near the forked cutoff to the float pond in late afternoon darkness, around 4:30 p.m. The owls screeched while flying through the forest and perched atop spruce trees. Other walkers report seeing a pair of the owls.
The largest of the "tufted" owls in North America, the Great Horned Owl, is one of six owl species seen regularly in Southeast Alaska. Its name reflects its prominent ear tufts or "horns."
Creatures of the night, owls have extremely sharp hearing and vision to hunt amid the quiet shadows that that elude our lesser senses.
They can distinguish features in light one-tenth of the lowest level in which we can see. Owls have binocular vision to focus on distant objects, with a long focal length much like the telescopic lens on a camera.
Their field of view is only about a third of ours and their oversized eyeballs do not move. But owls simply turn their heads to see on either side, as much as 270 degrees behind them if necessary. It's as good as eyes on the back of your head.
As nocturnal hunters, they rely as much on acute hearing as on night vision. Owls can pinpoint direction of sounds because their right and left ear openings differ in size and are slightly out of line on the head. Thus, there is a slight difference in the time it takes for a sound to reach each ear and in the intensity of the sound. Even their trademark facial disks are stiff feathers designed to deflect the faintest of sounds to the ears.
Their wings are also engineered to aid in the hunt. Serrated edges allow them to fly silently, undetected, while still honing in on any sounds being made by their intended prey. Their mottled, barred brown feathers easily render them just another indistinguishable shadow of the night.
Juneau's Great Horned Owls feed primarily on voles, mice and an occasional bird, but as befitting a creature who ranges from the Arctic to the southern tip of South America, from dense forest to city parks, they are creatures of opportunity.
Great Horned Owls are considered among the most voracious of all raptors. Almost any living prey will do. Even other owls and small pets.
And size is not necessarily a deterrent. At the Sunny Point home of Jim and Mary Lou King, a Great Horned Owl killed a healthy captive Trumpeter Swan unable to escape to the safety of water. The owl weighed 2.6 pounds; the swan weighed 26 pounds.
Their strength comes from strong, sharp talons on all four of their toes. When they swing their outer toes backward they have maximum spread and maximum strength for striking or carrying prey. In one study it took a force of more than 28 1/2 pounds to open the talons of a Great Horned Owl.
One Great Horned Owl spent a winter's day perched on a spruce branch in a Mendenhall Valley backyard, to the noisy displeasure of the resident red squirrel. Though the owl could have easily obtained both quiet and a meal at the same time, it apparently had another entree in mind and the squirrel lived to chatter another day.
Biologists determine what owls have eaten by analyzing the contents of their pellets. Portions of their food that they can not digest, like bones, hair, and feathers, are compressed and regurgitated as compact pellets.
Owl courtship will begin soon, with nesting in March or April in a tree hollow or borrowed squirrel nest. There will be typically two or three eggs, but as few as one or as many as five. Both female and male will incubate eggs, for 26 to 30 days. Chicks remain in the nest for as much as 10 weeks.
It is prudent to give their nest wide berth. One photographer in another state was blinded while attempting to photograph a nesting Great Horned Owl.
Despite their strength, we are most fascinated by their extraordinary senses that far exceed our own. At night, when we feel most vulnerable and blind, they come into their own.
Little wonder that through the centuries they have been regarded with fascination and awe, fear and veneration. They have been despised and admired, considered wise and foolish, and associated with witchcraft and medicine, the weather, births and deaths.
To see one of these amazing birds, look for its silhouette against the gray dusk sky.
Juneau Audubon Society meets the second Thursday of each month. If you have suggestions for future columns or would like to share sightings or observations, e-mail Juneau Audubon Society members at firstname.lastname@example.org.
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