What Are Owl Ear Tufts For? Feathers, Not Ears

What are ear tufts made of?

Ear tufts are bundles of ordinary contour feathers, the same kind that cover the rest of the body, that grow longer and stand up from the top of the head. Ornithologists sometimes call them plumicorns, meaning “feather horns”. They have no special nerves or openings, and an owl with damaged tufts hears just as well.

The tufts sit roughly where cartoon ears would be, which is how they earned the misleading name. They give owls such as the great horned owl and the Eurasian eagle-owl their famous horned or cat-like silhouette.

Owls can move them. When an owl is alert, nervous or trying to hide, the tufts stand straight up. When it relaxes, they lie back or flatten against the head, and the owl can look completely different from minute to minute.

Where are an owl’s real ears?

An owl’s ears are openings in the skull on the sides of the head, behind and a little below the eyes. They are covered by feathers at the edge of the facial disc, the dish-shaped ring of feathers around the face. The facial disc works like a satellite dish, collecting sound and channeling it toward the ear openings.

In many owls, especially those that hunt in total darkness, the two ear openings are lopsided. In the barn owl, for example, one ear sits higher than the other. A sound from below reaches the two ears at slightly different times and volumes, and the owl’s brain uses those tiny differences to work out exactly where the sound is coming from, up or down as well as left or right.

Lopsided ears have evolved several times in owls, including in barn owls, the Strix owls such as the tawny owl, the long-eared and short-eared owls and the boreal owl. Some can catch prey hidden under leaves or snow by sound alone. Turning and tilting the head helps fine-tune this aim (see can owls turn their heads 360 degrees?).

Why do some owls have ear tufts?

Nobody knows for certain, and the tufts may serve more than one purpose. Three main ideas are supported by observations of owl behavior.

1. Camouflage. By day, an owl roosting against a tree trunk raises its tufts, pulls its feathers tight and stretches itself thin. In this posture its outline looks less like a bird and more like a broken branch or a stub of bark. Comparisons across owl species have found that tufted owls tend to be nocturnal species that roost in trees and woodland, where this kind of disguise would be most useful.

2. Signaling mood. Owls raise and lower their tufts as their mood changes, and other owls can see this. Erect tufts show alertness or alarm; flattened tufts can go with aggression or submission, depending on the species. In low light, a bold outline may be easier to read than a facial expression.

3. Recognizing their own kind. Tuft shape and size differ between species. Where several similar owls live side by side, the tufts may help them recognize members of their own species, which matters when choosing a mate or defending a territory.

A further idea is that tufts make an owl’s head look like the head of a mammal with ears, such as a cat, which might deter some predators or mobbing birds. This is harder to test and remains speculative.

Which owls have ear tufts?

Tufts are common in a few large groups, such as the eagle-owls, the screech owls and the scops owls, and absent in many others. Here are some of the best known in Europe and North America:

Owls without tufts, such as the tawny owl and barn owl of Britain (see owls in the UK), hear at least as well as tufted owls. Their round heads simply rely on other forms of camouflage.

Myths and facts

• Myth: owls hear through their tufts. The tufts contain no ear openings and do not funnel sound.
• Myth: an owl without tufts is a young bird. Tufts are present in young owls of tufted species once their adult feathers grow in; untufted species never grow them.
• Fact: the name “long-eared owl” is misleading. Its long tufts are feathers, and its real ears are under the facial disc like those of any other owl.
• Fact: an owl’s hearing is exceptional. Owls that hunt in darkness can locate prey precisely by sound alone, using their facial disc and lopsided ear openings, not their tufts.