cushat vs wood pigeon

cushat

noun

  • A pigeon, wood pigeon or ring dove. 

wood pigeon

noun

  • The common wood pigeon, an Old World species of pigeon, Columba palumbus. 

  • A very large (up to 650 grams) species of pigeon native to New Zealand, Hemiphaga novaeseelandiae. 

  • Any of several related species of pigeon in the genus Columba. 

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