Locating Prey Through Hearing

a transparent lens and back onto the retina. They have far better eyesight than humans do. With plenty of light, Barn Owls found hunting during the day are able to locate their prey by sight from great distances, and to glide in for the kill.

Compared with other birds of prey, the wing tips of an owl are much softer; this enables it to fly silently.

Barn Owls have a highly-developed sense of hearing, thought to be 35 to 100 times more sensitive than our own human hearing, allowing them to hunt in almost complete darkness. They can hear squeaking, scratching or rustling through the dirt, leaves, or grass and can pinpoint the location of that sound in a second and then align their beak towards the location of their prey. Taking off from a vantage point, the Barn Owl flaps its wings silently, while swinging its feet back and forth. Then, just before its head collides with the ground and the unsuspecting prey, the owl throws its head back, thrusts its feet forward and sinks its razor sharp talons deep into the body of the prey. Because owls are typically active at night, they have a highly-developed auditory (hearing) system. The ears are located at the sides of the head, behind the eyes, and are covered by the feathers of the facial disc. It should be noted that tufts resembling ears on some species like Great Horned Owls, are not ears at all, but simply display feathers. An owl uses its unique, sensitive ears to locate prey by listening for the slightest movements through leaves, foliage, or even snow. When the owl hears a noise, it is able to tell the direction because of the minute time difference in which the sound is perceived in the left and right ear. If the sound was to the left of the owl, the left ear would hear

it before the right ear. The owl then turns its head so the sound arrives at both ears simultaneously - then it knows the prey is right in front of it. Owls can detect a left/right time difference of about 0.00003 seconds—that’s 30 millionths of a second!

An owl can also tell if the sound is higher or lower by using the asymmetrical or uneven ear openings. In a Barn Owl, the left ear opening is higher than the right - so a sound coming from below the owl’s line of sight will be louder in the right ear. The translation of left, right, up and down signals are combined instantly in the owl’s brain, and create an image of the space where the sound source is located. Studies of owl brains have revealed that the medulla (the area in the brain associated with hearing) is much more complex than in other birds. A Barn Owl’s medulla is estimated to have at least 95,000 neurons - that is three times as many as a crow. Once the owl has determined the direction of its next victim, it will fly toward it, keeping its head in line with the direction of the last sound the prey made. If the prey moves, the owl is able to make corrections mid-flight. After closing in on the prey, the owl will bring its feet forward and spread its talons in an oval pattern, and, just before striking, will thrust its legs out in front of its face and often close its eyes before the kill.

The asymmetrical nature of owls’ ear location on their head gives them amazing accuracy in locating prey.

What makes an owl especially stealthy is its remarkable ability to turn its head 270 degrees, meaning by turning the head left and right, there’s no view that is out of the owl’s vision.