kestrel vs standgale

kestrel

noun
  • The common kestrel, Falco tinnunculus. 

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

standgale

noun
  • A bird, the stannel. 

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