The long beak of the pelican, with the large pouch attached to its lower jaw, makes it one of the most peculiar looking of all birds. However, not only is the large pouch of considerable use to the adult pelican but without it, the young pelicans would not get fed nearly so well.
So, how does the pelican use its pouch? Pelicans feed primarily on fish, and the pouch is a very efficient fishnet. It dips its pouch into the water and catches plenty of fish as much as it can. Then it drains water from the pouch and swallows the fish.
If the bird, as it flies along, sights a fish in the water below, it drops like a rock with a splash that can be heard for half a mile. If there is only a single fish the pelican will seize and swallow it, but if there is a shoal, the pelican is really in its element.
It swims forward, using its pouch as a scoop net. When the pouch is full of water and fish, the bird doses its mouth, and the water drains out leaving the fish safely caught in the pouch.
If the fishing is good, the pelican may not stop to eat but may rush back into the game until its bag is bulging. The capacity of the pouch is enormous, and it can be stretched considerably; one writer states that it can hold as much as 40 pounds of fish.
However, I doubt if even such a large bird as a pelican could keep from falling on its face with so heavy a load; certainly, it could not fly.
The pouch, like all good fishnets, is dried or at least aired occasionally. The bird tilts its head backward and opens its beak widely, causing the pouch to spread out over its chest. There the pelican stands, with its mouth agape and its bare pouch hanging out, certainly one of the most ridiculous sights in the bird world.
Young pelicans are fed by regurgitation, and the pouch makes a handy serving bowl. The mother pelican opens her mouth, burps, and a quart or so of ill-smelling but wholly enjoyable fish soup flows into the pouch.
The young stick their heads in and greedily consume the contents of the pouch, sometimes almost falling into it in their eagerness to get their stomachs full. It was at one time thought that live fish in water was carried in the pouch to the young, but there is no evidence to support this theory.