Bad Omens.
Messengers of Misfortune.
These are just some of the names owls have been called, as they symbolize the mysterious and shadowy world of nighttime creatures.
Did you know?
In spite of their sometimes sinister appearance and ghostly calls, owls are unique among birds and are particularly valuable as rodent predators. A single barn owl can eat over a thousand mice in a year!
Formidable hunters, owls arrive upon their prey without a sound. How? The wings have downy fringes along the stiff flight feathers which muffle sound as the owls approach their prey.
With probably the most acute hearing of any bird, owls can hear sounds ten times fainter than a person can detect. Several distinctive features make this possible.
- Owls have an extra large ear opening surrounded by deep, soft feathers that funnel sound. The feathers over the ear, called auriculars, are modified to be loose and airy.
- Owls also have a moveable flap of skin controlled by muscles around the ear opening. This flap protects the ear and concentrates sound waves coming from behind. Many owls also have asymmetrical ear openings. The opening in one ear will be higher than in the other ear. This allows the owl to pinpoint its prey accurately.
- An owl's entire face acts as an outer ear, shaped like two satellite dishes that funnel sound to the ears. Some owls also have ear tufts, feathers sticking up on the top of both sides of the head. These, however, do nothing to improve hearing.
Barn Owl
Great Horned Owl
Saw-whet Owl. USFWS photos
Birds have relatively large eyes compared to the size of their head. A human eye weighs less than 1 percent of the weight of the head. But owls have the largest eyes. Owl eyes are so large that there is little room in their skulls for eye muscles. Thus an owl turns its head, sometimes as much as 270 degrees, rather moving its eyes, to follow an object.
Contrary to popular belief, owls have excellent vision both in daylight and at night. Their eyes are ten times as light-sensitive as human eyes. This is due to the concentration of light sensitive rods in the retina, but at the expense of color-defining cones. So, although owls see well in dim light, they see very little color.
Because they swallow their prey whole or nearly so, owls regurgitate pellets containing undigested parts of their prey. They can digest all but the bones, feathers or fur. They eject this as a hard fur or feathered pellet.
Owls do not build their own nests. Instead they use old hawk nests, squirrel nests, natural cavities, buildings or constructed boxes.
Owls in the Chesapeake Bay
Several species of owls inhabit the Chesapeake Bay region. Probably the most familiar is the great horned owl. This large brown owl is noted by its large yellow eyes, white throat patch and large ear tufts. Its call is a series of low hoots. Another "eared" owl is the long eared owl which is similar to the great horned except its ears tufts are closer together and it is smaller and slimmer.
The eastern screech owl is a small eared owl (8 inches tall) with coloring varying from rust to gray. Its call is a long quivering whistle.
Of the earless owls, the barn owl is easily recognized by light colors and heart shaped face. As the name implies, the barn owl nests in barns, abandoned buildings and tree cavities. Its call is a long raspy, ghost-like screech.
The barred owl is often referred to as the "hoot owl." Its call is made of hoots that sound like the phrase “Who-cooks- for-you, who-cooks-for-you-all.”
The northern saw-whet owl is the smallest of the eastern owls (7 inches tall) and is often found roosting in dense evergreens or in thickets. Its call is a series of toots or whistles.
As more and more land is developed, more of our natural predators are lost. Left unchecked, rodents and other small mammals can become pests. Owls continue to play a significant role in our ecosystem by controlling these populations.
For more information on owls:
The Owl Pages: Owls of North America
http://www.owlpages.com/owls.php?location=North+America
John James Audubon’s Birds of America: The Owl Family Striginae
http://www.audubon.org/bird/BoA/BOA_index.html