cheep vs chirl

cheep

verb
  • Of a small bird, to make short, high-pitched sounds. 

  • To express in a chirping tone. 

intj
  • The short, high-pitched sound made by a small bird. 

noun
  • A similar-sounding short high-pitched sound 

  • A short, high-pitched sound made by a small bird. 

chirl

verb
  • To emit a low sound; to warble. 

noun
  • A kind of musical warble. 

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