Why do pigeons bob their heads?

Have you ever watched a pigeon walk? As they move, their heads bob up and down. Scientists have a few theories about why they do this, but the most popular one has to do with how pigeons see!

Try this: hold your hand out straight in front of you. Now close your left eye and look at your hand. Then open your left eye and close your right. Keep switching between eyes, as fast as you can. Can you see how your hand appears to move a little to the side each time you switch?

That happens because our eyes are in the front of our heads, which give us binocular vision. Since both our eyes can focus on something in front of us, but each one sees it just a little bit differently, when both our eyes are open, we can see depth. We know how far away something is. Most hunters have eyes like ours, because when you’re lunging for your prey, you need to know how far away it is.

Pigeons are different: their eyes are on the sides of their heads. This means they can see 340 degrees around themselves (we can only see about 120 degrees). This gives them an incredible range of vision to spot predators, but it means they can’t see depth unless something is straight ahead of them. To make up for that, they can move their heads up and down. By seeing how far objects seem to move, they can tell which one is closer!