The Collaborative International Dictionary of English v.0.48:

Manx shearwater \Manx shearwater\ prop. n. (Zool.),
   A small black-and-white oceanic bird (Puffinus puffinus, or
   Puffinus anglorum), common in the Eastern North Atlantic.
   Called also Manx petrel, Manx puffin. It is avariety of
   shearwater. It was formerly abundant in the Isle of Man.
   [1913 Webster]