Nature Nugget – Owl Senses

There are 162 species of owls in the world ranging in size from the tiny Elf Owl, less than six inches in length and weighing 1.5 ounces, to the giant European Eagle Owl weighing up to nine pounds and with nearly a six-foot wingspan. Owls are found on every continent, except Antarctica, and on many oceanic islands far from any continent. They occur in habitats from the cold arctic tundra to hot, low deserts. Most owls are nocturnal (active at night), but some are diurnal (active during the day). The larger species feed on small mammals such as rabbits, skunks, and foxes, whereas the smallest owls are mainly insect eaters. Most average-sized owls feed on rodents and birds. A few, such as the fishing owls, feed on fish.

The most striking feature of an owl is its eyes. They are very large and forward facing and, depending on the species, may account for one to five percent of the owl’s body weight. The forward facing aspect of the eyes, which gives it a “wise” appearance, provides it a wide range of “binocular” vision (seeing an object with both eyes at the same time). This means the owl can see objects in three dimensions and can judge distances. An owl’s field of view is approximately 110 degrees with about 70 degrees being binocular vision. In comparison, humans have a 180-degree field of view with 140 degrees being binocular. An owl’s eyes are large in order to improve their light gathering capacity. They do not have eyeballs like other animals but have eyes that are elongated tubes. Therefore, they cannot “roll” or move their eyes but can only look straight ahead. The owl makes up for this with its long, very flexible neck, allowing it to turn its head nearly completely around and almost upside down.

Even more impressive than the owl’s vision is its highly developed hearing. Its ears are located on the sides of its head behind the eyes and are covered with feathers. The shape of the ear opening or aperture varies from round and small to an oblong slit, depending on the species. Some species have a valve called an operculum covering the ear opening. An owl’s hearing is very acute and sensitive, allowing it to hear even the slightest movements of its prey. Some of the more strictly nocturnal species have asymmetrically set ear openings (i.e., one ear is located higher than the other). These same species use their pronounced facial discs like radar dishes to guide sounds into their ears. When an owl hears a sound, it is able to tell its direction because of the minute time difference in which the sound is perceived in the left and right ear. Turning its head so that the sound arrives at both ears simultaneously puts it looking in the right direction from which the sound is coming. Owls can detect a left/right time difference of about 0.00003 seconds (30 millionths of a second)! Using its asymmetrical ear openings, it lines up on the sound on the vertical plane. All these signals combine instantly in the owl’s brain, creating a mental image of the space where the sound source is located. So accurate are these senses that an owl can capture prey in total darkness without the aid of its eyes and can even capture prey under snow.

Like the special senses provided for the owls, the Lord has given us special senses (i.e., touch, taste, smell, hearing, sight), according to our needs, for our function and enjoyment. “All should guard the senses, lest Satan gain victory over them; for these are the avenues to the soul.” Testimonies, vol. 3, 507.

David Arbour writes from his home in DeQueen, Arkansas. He may be contacted by e-mail at: landmarks@stepstolife.org.