that only water flows out and the fish remains inside it. this process is important as a pelican cannot eat or fly with its bill full of water. finally, with a jerk of its head, it pushes the fish down its throat.
a pelican can even turn the pouch inside out by turning its neck!
box: the pelican also uses its pouch also as a cooling device. when it is warm, it swings its pouch to cool itself. 