A technique for marking waterfowl ducklings less than 1 day old was developed to permit subsequent identification in the hand. Marking was accomplished by removing the alulae from wings of mallard (Anas platyrhynchos) ducklings with a small scissors or clipper. No differences in growth rate, behavior, or flight capability were noted between clipped and nonclipped birds. Thirty-five hundred ducklings were clipped when less than 1 day old, and 1,880 of these birds were subsequently examined at 4 1/2 weeks of age. Significant (P <0.01) differences in successful removal of right and left alulae indicate that right-handed persons should exercise more care when clipping left wings than when clipping right wings. Alula removal appears to be effective for marking the wings of waterfowl.