When a pigeon walks, its head does not move back and forth regularly, but stretches forward all the time  As they walked, the pigeon leaned its neck forward, then kept its head still, waiting for its body and claws to follow
When the pigeon walks, it may appear the natural reflex of the neck and head muscles when it raises its wings and throws its feet, so its head is constantly moving
 Some scholars have made hypotheses about the phenomenon that pigeons stretch their necks when walking: while waiting for the body to follow up, the temporary rest of the head helps the pigeons to get a stable field of vision and see the food around them