peregrine : Idioms & Phrases

• noun a widely distributed falcon formerly used in falconry
  peregrine; Falco peregrinus.
  

WordNet

• (Zoöl.), a courageous and swift falcon (Falco peregrinus), remarkable for its wide distribution over all the continents. The adult plumage is dark bluish ash on the back, nearly black on the head and cheeks, white beneath, barred with black below the throat. Called also peregrine hawk, duck hawk, game hawk, and great-footed hawk.

Webster 1913