Have you ever watched a raptor perched on a windy day, hover in the air or perch on an object that is unstable or wobbly? Next time you see one in this type of scenario, check out how their body moves back and forth while their head remains in one spot. Birds seem to have a built-in gyroscope that operates automatically in situations where it is helpful to have keep their head still, such as when looking for prey. The eyes of a hawk are fixed in the head and vision works best when the eye is not moving since this eliminates blur. For example, when scanning quickly with your eyes or binoculars, it is difficult to focus on a subject and the image becomes blurred until you stop scanning. So, a hawk with its head still can see a mouse running along the ground much easier because the image, including the background, remains still. Watch the video below of an American Kestrel hovering in place to see how the head stays completely still while the body and tail adjust for the wind.
Raptor Fun Facts are sponsored by Mark Miller Subaru. HawkWatch International is proud to be Mark Miller Subaru's #SubaruLovesTheEarth partner.