Attached-shadow orientation perceived as depth by chickens reared in an environment illuminated from below.
D000818:Animals; D001522:Behavior, Animal; D002645:Chickens; D003463:Cues; D003867:Depth Perception; D004193:Discrimination Learning; D006798:Housing; D008029:Lighting; D009949:Orientation; D010469:Perceptual Distortion; D010781:Photography