Dorsal and ventral subcutaneous, dilatable air pouches play a part in the social life of the Marabou stork. Inflation of the ventral pouch indicates the dominance of an individual over its neighbours whilst inflation of the dorsal pouch indicates apprehension. Both are inflated simultaneously during courtship. Air enters the ventral pouch by a complicated route within the left orbit. The dorsal pouch most probably receives air by way of the first anterior dorsal secondary bronchus of the lung and the cervical air sac.