Ontogeny of feeding and drinking in the greater rhea (Rhea americana)

Feeding and drinking movements of the greater rhea chick are analyzed. Feeding consists of five movements in the following sequence: orientation, pecking thrust, head lift, forward head jerk and swallow. Drinking is less complex, consisting of a downward movement followed by an upward movement. Adult movements are basically similar; there is a slight trend toward increased variability and decreased energy expenditure. Feeding movements are observed prior to feeding initiation. Drinking movements are first performed during initial water contact. Experience with food and water plays a major role in the development of response efficiency.