Matthew R. Kinloch Glenn H. Olsen Thomas W. Cronin 2007 Head-bobbing is a common and characteristic behavior of walking birds. While the activity could have a relatively minor biomechanical function, for balance and stabilization of gait, head-bobbing is thought to be primarily a visual behavior in which fixation of gaze alternates with a forward movement that generates visual flow. We studied head-bobbing in locomoting whooping cranes (<i>Grus americana</i>) and sandhill cranes (<i>Grus canadensis</i>), using food strewn on the ground to motivate them to walk or run. When the cranes walked, head-bobbing proceeded in a four-step sequence that was closely linked to the stepping cycle. The time available for gaze stabilization decreased with travel speed, and running cranes did not head-bob at all. As a crane extended its bill towards the ground for food, it also exhibited a series of short head-bobs that were not associated with forward travel. Head-bobbing is a flexible behavior that varies with gait and with visual search, most notably as the cranes prepare to strike with the bill. application/pdf 10.1007/s10336-007-0199-0 en Springer-Verlag Head-bobbing behavior in walking whooping cranes (<i>Grus americana</i>) and sandhill cranes (<i>Grus canadensis</i>) article