Owls are birds of prey, meaning that they actively hunt live prey such as smaller birds, reptiles, small mammals and so on using very unique adaptations that set them aside from any other of the bird families.
Exceptional eyesight and superb hearing is two of the owl’s best features and combining these with the ability to fly completely silently makes for a formidable predator using stealth to take down its prey.
The most unique adaptation of Owl feathers is the comb-like leading edge of the primary wing feathers referred to as “flutings”. With a normal bird in flight, air rushes over the surface of the wing, creating turbulence, which makes a gushing noise. With an Owl’s wing, the comb-like feather edge breaks down the turbulence into little groups called micro-turbulences. This effectively muffles the sound of the air rushing over the wing surface and allows the Owl to fly silently.
The ability to fly silently makes it possible for an owl to hunt its prey using stealth and also gives it the opportunity to use its superb hearing in flight to pick up any changes in the movement of the prey. Although owls have excellent eyesight, they actually use their hearing a lot more in the hunting process than their eyes.
Some owls have asymmetrically set ear openings, meaning one ear is higher than the other. This is a very common occurrence in owl species which are completely nocturnal, such as the White-faced Scops Owl. These species have a very pronounced facial disc, which acts like a “radar dish”, guiding sounds into the ear openings. The shape of the disc can be altered at will, using special facial muscles.
An owl uses these unique, sensitive ears to locate prey by listening for prey movements through ground cover such as leaves, foliage, or even snow. When a noise is heard, the owl is able to tell its direction because of the minute time difference in which the sound is perceived in the left and right ear. Say for instance a mouse moves to the left of an owl, the left ear will pick up the noise before the right ear, the owl will then start turning its head until it hears the sound at the same time in both ears, this is how the owl knows when the prey is directly to the front of it. Being able to turn the head 270 degrees to either side also helps with this detection of prey using hearing.
Over the years there has been a lot of different folk lore and believes regarding owls all over the world and with many different cultures. But all and all these are extremely interesting birds and one of the most formidable predators keeping an eye, and ear out for their next victim.
Piet – Kapama River Lodge
25/02/2013
