Tyrannus vociferans vs Cassin's kingbird

Tyrannus vociferans and Cassin's kingbird both are nouns.

Word	Noun	Adjective	Verb	Adverb
Tyrannus vociferans	Yes	No	No	No
Cassin's kingbird	Yes	No	No	No

As nouns, Tyrannus vociferans and Cassin's kingbird are synonyms defined as:

Tyrannus vociferans and Cassin's kingbird: a kingbird seen in the southwestern United States; largely grey with a yellow abdomen

Tyrannus vociferans (noun)	Cassin's kingbird (noun)
a kingbird seen in the southwestern United States; largely grey with a yellow abdomen	a kingbird seen in the southwestern United States; largely grey with a yellow abdomen