Assertion: trumpeter swan | /r/HasProperty | one of the heaviest birds
Facets:
value: in north america
type: LOCATION
Source sentences:
text: The trumpeter swan is one of the heaviest birds, which is capable of flight.
text: They are the heaviest bird species that is native to North America.
text: Trumpeter swans are the largest native waterfowl and the heaviest flying birds in North America.