trumpeter swan vs Cygnus buccinator

trumpeter swan and Cygnus buccinator both are nouns.

Word	Noun	Adjective	Verb	Adverb
trumpeter swan	Yes	No	No	No
Cygnus buccinator	Yes	No	No	No

As nouns, trumpeter swan and Cygnus buccinator are synonyms defined as:

trumpeter swan and Cygnus buccinator: large pure white wild swan of western North America having a sonorous cry

Other synonyms of trumpeter swan include trumpeter.

trumpeter swan (noun)	Cygnus buccinator (noun)
large pure white wild swan of western North America having a sonorous cry	large pure white wild swan of western North America having a sonorous cry