bird-dog vs run away

bird-dog

run away

verb
  • To leave home, or other place of residence, usually unannounced, or to make good on a threat, with such action usually performed by a child or juvenile. 

  • To become a runaway. 

  • To flee by running. 

How often have the words bird-dog and run away occurred in a corpus of books? (source: Google Ngram Viewer )