grosbeak vs redbird

grosbeak

noun
  • Any of several finches and cardinals that have a large, powerful bill 

redbird

noun
  • Any of several unrelated American songbirds having red plumage, especially the tanager or cardinal. 

  • Any of various red cars formerly used in the New York City subway system; or a train of such cars. 

  • A capsule of secobarbital. 

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