culver vs turtle dove

culver

noun
  • A dove or pigeon, now specifically of the species Columba palumbus. 

  • A culverin, a kind of handgun or cannon. 

turtle dove

noun
  • Any of several (species of) birds, called by this traditional name, mainly in the genus Streptopelia, of the family Columbidae (doves and pigeons, which also included the extinct passenger pigeon, dodo, and solitaire). 

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