dark-eyed junco vs fieldfare

dark-eyed junco

noun
  • Junco hyemalis, a passerine bird in the passerine family Passerellidae. 

fieldfare

noun
  • A large thrush, Turdus pilaris, a bird of Eurasia. 

How often have the words dark-eyed junco and fieldfare occurred in a corpus of books? (source: Google Ngram Viewer )