rifleman vs skua

rifleman

noun
  • A small wrenlike insectivorous passerine bird endemic to New Zealand, Acanthisitta chloris, the titipounamu. 

  • A person especially skilled in the use of a rifle. 

  • A soldier trained to use a rifle as their primary weapon. 

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 rifleman and skua occurred in a corpus of books? (source: Google Ngram Viewer )