birdcage vs sheepfold

birdcage

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

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

sheepfold

noun
  • An enclosure for keeping sheep. 

  • A flock of sheep. 

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