dung beetle vs skua

dung beetle

noun
  • Any of the true dung beetles of subfamily Scarabaeinae. 

  • Any of the beetle of the family Scarabaeidae (scarab beetles), especially of the subfamilies Scarabaeinae and Aphodiinae, noted for rolling dung into balls for use as food or as brooding chambers. 

skua

noun
  • Any of various predatory seabirds of the family Stercorariidae that often chase other seabirds to steal their catches. 

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