Tetrao uragallus

from The Collaborative International Dictionary of English v.0.48

Capercailzie \Ca"per*cail`zie\, or Capercally \Ca"per*cal`ly\,
   n. [Gael, capulcoile.] (Zool.)
   A species of black Old World grouse ({Tetrao uragallus}) of
   large size and fine flavor, found in northern Europe and
   formerly in Scotland; -- called also {cock of the woods} and
   {horse of the wood}. [Written also {capercaillie},
   {capercaili}.]
   [1913 Webster]