aviary vs birdcage

aviary

noun
  • A house, enclosure, large cage, or other place for keeping birds confined; a birdhouse. 

birdcage

noun
  • A cage to keep pet or zoological specimen birds in. 

  • A game of chance played with dice; chuck-a-luck. 

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