seahawk vs skua

seahawk

noun
  • A rapacious gull-like bird of the genus Stercorarius. 

  • An osprey, Pandion haliaetus. 

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