— Active | Passive

"The pink-backed pelican uses its distendable throat pouch as a fishing net, scooping fish and crustaceans from the water as it swims. When it opens its bill underwater, the sudden inflow of water carries the prey in with it. Then the pelican raises its head to drain out the water before swallowing the prey." (Foy and Oxford Scientific Films 1982:157)

The Pelican's pouch shows the potential of flexible/expanding membranes at the interface of wet/dry environments.