bushman's clock vs laughing kookaburra

bushman's clock

laughing kookaburra

noun
  • A species of kookaburra, Dacelo novaeguineae, native to eastern Australia and famed for its loud laugh-like call. 

How often have the words bushman's clock and laughing kookaburra occurred in a corpus of books? (source: Google Ngram Viewer )