Chateura pelagica vs chimney swift

Chateura pelagica

chimney swift

noun
  • A rapid-flying bird that feeds on flying insects, Chaetura pelagica, with a breeding range in the eastern US extending into Canada and winter range in northwestern South America. 

How often have the words Chateura pelagica and chimney swift occurred in a corpus of books? (source: Google Ngram Viewer )