common raven vs hooded crow

common raven

noun
  • A large all-black passerine bird in the crow family, Corvus corax. 

  • A dark-colored South Asian swallowtail butterfly, Papilio castor 

hooded crow

noun
  • A grey and black Eurasian crow, Corvus cornix. 

How often have the words common raven and hooded crow occurred in a corpus of books? (source: Google Ngram Viewer )