October 18, 2012 Stealthy Pacific Northwest Owls
Owls are awesome. Their ancestors date as far back as 80 million years. At least eight different owl species inhabit the Pacific Northwest forests. They have remarkable plumage. Different colors and patterns mimic forested landscapes.
Owls are also formidable hunters. They are silent fliers. The forward edge of the tip of their wings is fluffy instead of smooth, and this interrupts airflow over each wing and eliminates turbulence or noise. No other bird, and there are 10,000 different species of birds on the planet, has perfected this stealthy adaptation. Each shaft that holds an individual feather in place is held by one million minute hooks.
They hunt at night, but not exclusively. And they hear their prey by differentiating sounds from the right or left based on when the sound waves reach each ear independently. In fact, I once saw a boreal owl punch through four feet of deep snow pack and snatch a scurrying vole.
Owls are birds of prey and rely on powerful beaks to rip the prey apart and sharp claws called talons. They have an outer toe on each foot that moves backward or forward to grasp prey. Beaks are also able to crack open seeds, pluck fruit from bushes or to snap up insects.
In order to operate successfully in the night, owls depend on specialized eyes packed with tiny baton-like cells called rods. Owl eyes, like humans, face forward. This gives them excellent frontal vision. But like humans, this causes them to look to the left and right in order to see in those directions. If you ever have the pleasure of observing an owl, you’ll notice that they perform this action very swiftly.
In addition to navigating silently in a dark forest and hearing prey; owls also have an acute sense of smell. They are perfect flying hunters. They swallow their prey whole or rip apart large prey together with fur or feathers. The indigestible parts are regurgitated in a compact, felted mass known as casting or a pellet. One of my most memorable moments a child was discovering an owl’s pellet filled with mouse hairs and bones.
Except for the burrowing owl, all other owls in in the Pacific Northwest need trees. Most nest in cavities but some will build platforms of moss and lichen, and trees are used for roosting as well as perching. Females are larger than males and exclusively incubate the brood. Owls are monogamous. The female depends upon the male to feed her during incubation. Clutch sizes range from two to 14.
Scientists are now using the presence of boreal owls in the west Kootenays, British Columbia and elsewhere as a barometer of forest health. If harvesting has occurred and boreal owls are still present on the landscape then the high elevation forests are successfully rebounding from disturbance. The spotted owl, on the other hand, requires large tracts of ancient forests in order to successfully reproduce. Unfortunately this owl species is in danger because its habitat in southwestern British Columbia and coastal Washington, Oregon and northern California is being destroyed.
Owls in flight appear headless. Surely this must account for the false lore that if seen in the wild – bad luck and death is imminent.
Text © by Dr Reese Halter 2012. All rights reserved.
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