goshawk vs gyrfalcon

goshawk

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

gyrfalcon

noun
  • Falco rusticolus, a large bird of prey that breeds on Arctic coasts and islands of North America, Europe and Asia. 

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