brown falcon vs kestrel

brown falcon

noun
  • Falco berigora, a member of the falcon genus found in the drier regions of Australia. 

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 brown falcon and kestrel occurred in a corpus of books? (source: Google Ngram Viewer )