Fig. 2. (A,B) Cineradiograph of a cooing ring dove during maximum inflation of the esophagus; (A) lateral view; (B) frontal view. The course of the trachea around the esophagus is indicated by arrowheads. The crop represents a separate cavity from the inflated upper esophagus. (C,D) Schematic drawing of the (C) lateral and (D) frontal view of a dove during full inflation of the esophagus. Cr, crop; Es, esophagus; Lx, larynx; Tn, tongue; Tr, trachea. Drawings by Sue Anne Zollinger.