magnificent frigatebird vs skua

magnificent frigatebird

noun
  • A species of frigatebird native to the tropical Atlantic, Fregata magnificens. 

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