bobwhite vs partridge

bobwhite

noun
  • Any one of four species of quail in the genus Colinus, of the bird family Odontophoridae, limited to the Americas. 

partridge

noun
  • Any bird of a number of genera in the family Phasianidae, notably in the genera Perdix and Alectoris. 

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