How Can Owls Turn Their Heads So Far?

The short answer

An owl can turn its head as far as 270 degrees, which is three-quarters of the way around, to the left or to the right. It has to, because an owl’s big eyes are fixed in place and can’t roll around the way yours can. Its body is built for all that turning: its neck has 14 bones, twice as many as yours, and the blood tubes in its neck have extra room and little storage pools, so blood keeps reaching its brain and eyes the whole time ¹.

Eyes that can’t move

Try this: keep your head still and look to the side. Your eyes can roll around in their sockets, so you can look sideways without turning your head.

An owl can’t do that. Its eyes are huge for its size, so they can gather lots of light to see at night, and they’re shaped more like tubes than balls. They’re held tight in the skull and can’t roll ¹. So whenever an owl wants to look at something, a mouse rustling in the grass, a sound behind it, it turns its whole head to point its eyes there.

A neck full of bones

Your neck has 7 bones, stacked like a little tower. An owl’s neck has 14 ¹. Each place where two bones meet can bend and twist a little, and with twice as many places to bend, an owl’s neck can turn much farther than yours. Under all those fluffy feathers, an owl’s neck is longer and bendier than it looks.

Keeping the blood flowing

Turning that far could cause a problem. Blood travels up the neck in tubes to bring the brain and eyes the food and oxygen they need. If you twist a tube hard, it can get pinched, the way a garden hose stops spraying when you kink it.

An owl’s neck solves that in three ways ¹:

• The holes in the neck bones that the blood tubes run through are about 10 times wider than the tubes, so the tubes have room to move instead of getting squeezed.
• Just under the owl’s jaw, the blood tubes widen into little storage pools that hold extra blood for the brain and eyes while the owl is turned.
• The tubes are connected to each other in extra places, so if one gets squeezed, blood takes another path.

Scientists at Johns Hopkins University figured this out in 2013 by studying owls that had died of natural causes ¹.

So

An owl turns its head up to three-quarters of the way around because its big eyes can’t move, so it moves its head instead. Fourteen neck bones give it lots of places to bend, and roomy blood tubes with storage pools keep blood flowing to its brain and eyes the whole time it’s turned.