Pigeons bob their heads to stabilize their vision rather than to keep a rhythm.

The phenomenon of head-bobbing in birds is scientifically known as optokinetic behavior. Research conducted at Queen's University in the 1970s by Dr. Barrie Frost used treadmills to prove that pigeons only bob their heads when their surroundings move relative to their eyes. When pigeons were placed on a treadmill and kept stationary relative to the room, they stopped bobbing their heads entirely.The movement consists of two phases: the 'thrust' and the 'hold.' During the thrust, the head moves forward rapidly. During the hold phase, the head remains perfectly stationary in space while the body moves forward under it. This hold phase accounts for about 85% of the bird's walking time, providing a series of stable 'snapshots' for the brain to process.Because pigeons have eyes on the sides of their heads, they have a wide field of view but poor binocular depth perception. Stabilizing the image is critical for detecting the parallax motion required to judge distances accurately. Without this behavior, the bird's vision would be a constant blur, making it impossible to distinguish a small grain of food from a pebble while in motion.