Assertion: petrel | /r/HasProperty | a species of gadfly petrel
Facets:
Source sentences:
text: The Pycroft's petrel is a species of gadfly petrel (genus Pterodroma), and is thought to be closely related to the Stejneger's petrel.  
text: The Vanuatu petrel or Falla's petrel (Pterodroma occulta) is a species of gadfly petrel.