black grouse vs goshawk

black grouse

noun
  • A large, black bird with a lyre-shaped tail, Lyrurus tetrix (syn. Tetrao tetrix). 

goshawk

noun
  • Any of several birds of prey, principally in the genus Accipiter. 

How often have the words black grouse and goshawk occurred in a corpus of books? (source: Google Ngram Viewer )