bunting vs tree sparrow

bunting

noun
  • Any of various songbirds, mostly of the genus Emberiza, having short bills and brown or gray plumage. 

  • A pushing action. 

  • Strips of material used as festive decoration, especially in the colours of the national flag. 

  • A warm, hooded infant garment, as outerwear or sleepwear, similar to a sleeper or sleepsack; especially as baby bunting or bunting bag. 

  • Flags considered as a group. 

  • A thin cloth of woven wool from which flags are made; it is light enough to spread in a gentle wind but resistant to fraying in a strong wind. 

  • A strong timber; a stout prop. 

tree sparrow

noun
  • A bird of the species Passer montanus 

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