Let’s go on a hunt with an owl and learn, step-by-step, about their amazing capabilities. Possessing even just one of their capabilities would mean having a superpower, but owls have far beyond just one extraordinary gift, possessing multiple talents in their sight, hearing, flight and more.

Pennsylvania has six resident owl species, plus two more species that come in the winter, and has even had rare reports of Great Gray Owls that wandered down from Canada. To learn more about Pennsylvania’s owls and their conservation, click here.
Most, but not all owls, are nocturnal. Some, like the Burrowing Owl of Florida and the west-central U.S., are active during the day. The Snowy Owl is typically diurnal or crepuscular—it is most active either at twilight or during the day, especially in the continuous daylight of the Arctic summer. But I’ll focus on here on a Great Grey Owl named Shadow, who is getting ready to hunt in the dark, snow-covered boreal forest where she lives. She provides an excellent example of the superpowers of vision, hearing, flying, and foot and leg anatomy that not only she but all owls possess to varying degrees.

Meet Shadow the Night Hunter

Shadow will likely scan her environment first with her large, binocular-vision eyes, which have a high density of rod cells allowing her to see well in the dark. She uses her sight, together with auditory clues, to locate prey. She will also turn her head up to 270 degrees to help pinpoint any potential sound of prey. She can’t move the eyes in her sockets—they are fixed—so neck flexibility is important. Shadow has 14 neck vertebrae versus our 7, giving her much greater flexibility than our necks have. She also has the ability store blood that can be directed to her brain when her head is turned, and flexible carotid arteries that stretch easily.

Shadow hears a vole beneath the snow nearly 100 feet away. This sensitivity is due to her exceptionally precise auditory nerve cells and the structure of her inner ear. In addition, she has large ear openings covered by specialized feathers that can be adjusted to control the amount of sound entering. This allows her to fine-tune her hearing. Her ears are positioned asymmetrically on her head, with one ear higher than the other. This unique arrangement allows her to determine the exact location of sounds in three dimensions. As if that’s not enough, she has two further adaptations that help her detect and pinpoint sound direction. One is that the feathers around her ears help reduce wind noise, which enhances her ability to hear subtle sounds. Finally, her round facial disc acts like a satellite dish funneling sound waves towards her ears. This serves to amplify even the faintest noises made by prey hidden beneath the snow.

It’s time to follow that sound to a meal and learn about another amazing capability: silent flight. It’s not just one attribute that makes Shadow’s flight silent, it’s several. First, her feathers are soft and velvety, which helps to absorb sound as she glides. She also has broad wings with a large surface area relative to her body size. This design reduces the amount of noise generated by movement through the air, enabling her to fly nearly effortlessly, with minimal wing flapping. Finally, Shadow’s primary feathers have a serrated or fringed leading edge, which helps to break up the turbulence that occurs when air flows over the wings. This reduces the noise typically created by the friction of air against feathers. The trailing edges of the flight feathers are also designed to reduce noise with soft, velvety surfaces that minimize the friction.

Shadow knows where her target is and dives into the snow, talons first, and takes hold of her prey. Even her legs have special modifications that are particularly adapted to hunting in the snow; they’re long, strong enough to break through a thick icy crust, and have warm insulating feathers. With all these advantages, Shadow still only hunts with a 70-80% success rate. Well, Shadow, enjoy your meal. You worked hard for it. You are truly an awesome bird!

Barbara Beck, Richland Township Bird Town Leader

Photo Credits:

Great Gray Owls, with permission by Brandon Swayser, Director of Environmental Science and Living Collections at the Allentown Da Vinci Science Center and Board Member at Lehigh Valley Audubon