churr vs rustle

churr

noun
  • A low vocal sound made by some birds. 

verb
  • To make the low vocal sound of some birds. 

rustle

noun
  • A movement producing such a sound. 

  • A soft crackling sound similar to the movement of dry leaves. 

verb
  • To make or obtain in a lively, energetic way. 

  • To steal (cattle or other livestock). 

  • To move (something) with a soft crackling sound. 

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