The black-faced spoonbill, and all other species of spoonbill, feed by sweeping their open bill from side to side. When prey such as a fish, crustacean, or insect enter, the very sensitive bill snaps shut, and the water is pressed out through small projections on the sides of the bill, similar to how baleen functions in whales.
A whimbrel, or chushakushigi in Japanese, was also feeding at the estuary this day. They use their long bill to probe for crabs, shrimp, and other creatures. When they catch a crab, they will shake off the legs, one by one, and then swallow the body whole. Then they eat each leg. Nothing is wasted.