mockingbird vs thrasher

mockingbird

noun
  • A long-tailed American songbird of the Mimidae family, noted for its ability to mimic calls of other birds. 

thrasher

noun
  • Any of several New World passerine songbirds, of the genera Toxostoma, Allenia, Margarops, Oreoscoptes and Ramphocinclus in the family Mimidae, that have a long, downward-curved beak. 

  • A fan of thrash metal music. 

  • A thresher shark. 

  • One who thrashes. 

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