birdcall vs hallo

birdcall

noun
  • An imitation of this cry. 

  • Any vocalisation of a bird. 

  • A device used to imitate this cry, so as to lure and catch birds. 

verb
  • To imitate the cry of a bird. 

hallo

noun
  • The cry "hallo!" 

  • A shout of exultation. 

verb
  • To cry "hallo" (to someone). 

  • To shout, or to call with a loud voice. 

  • To chase while shouting "hallo!" 

  • To shout (something). 

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