The Newell's Shearwater is a medium-sized shearwater measuring 12 to 14 inches with a wing span of 30-35 inches. It has a dark black back, contrastingly white underside and underwing, and a black bill that is sharply hooked at the tip. Its claws are well adapted for burrow excavation and climbing. Newell’s Shearwater can be identified by its very quick, almost frantic flapping style with the wings held straight. The Newell’s has a very distinctive call that sounds like a braying donkey, which can be heard in many places on Kauai just after sunset.