Streptopelia risoria vs ringneck dove

Streptopelia risoria

ringneck dove

noun
  • A domesticated dove with unclear taxonomic classification, often treated as its own species as Streptopelia risoria. Other sources classify it as subspecies of either Eurasian collared dove, Streptopelia decaocto or African collared dove Streptopelia roseogrisea. 

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