Fun fact 5 of 10
5. The owl doesn't turn its head 360 degrees, but it gets close
An owl can turn its head up to about 270 degrees, without damaging its neck or cutting off the blood flow to its brain. It needs this because its eyes don't move.
Fixed eyes, flexible neck
An owl's eyes are large and elongated, tube-shaped, and are held firmly in the eye socket. It can't move them sideways like we do. To look in another direction, the owl turns its whole head, and for this it has 14 vertebrae in its neck, twice as many as our seven.
Turning this far should twist the arteries in the neck. In 2013, researchers at Johns Hopkins University in the United States studied owl anatomy and showed how they avoid the problem. One of the arteries enters the neck higher up than in other birds, which leaves room for the turn, and there are vessels at the base of the skull that widen and store blood like small reservoirs.
These reservoirs keep the brain and eyes supplied while the head is turned. There are also connections between the vessels that offer alternative paths for blood if one of them becomes constricted. Together, these adaptations allow the owl to look behind it without moving its body, which is useful for a hunter that spends hours still and silent.
The owl's flight is also almost silent. The feathers along the edges of the wings have fringes, like a comb, that break up the airflow and muffle the sound. This way the prey doesn't hear the owl coming, and the owl itself hears better what lies ahead.
Did you know? In many owls, the ears sit at different heights on either side of the head. This asymmetry helps locate a sound vertically as well, and some species can hunt in the dark almost solely by hearing.
