The Bill-snap Reflex : a Feeding Mechanism in the American Wood Stork

Abstract

IN the course of field observations of the American wood stork (Mycteria americana) in Florida, the birds were seen to capture fish habitually from water so turbid or choked with vegetation that the use of visual cues was improbable. In such feeding behaviour, a stork typically inserts its partially open bill into the water, moves the bill slowly from side to side, and walks forward. Submerged vegetation is sometimes stirred with one foot and the wing on the same side is flashed open, presumably to startle concealed fish into the open bill. When a fish makes contact with the bill, the mandibles are quickly closed with considerable force. These feeding techniques have been previously described^1–3.