goshawk vs kestrel

goshawk

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

kestrel

noun
  • Any of various small falcons of the genus Falco that hover while hunting. 

  • The common kestrel, Falco tinnunculus. 

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