Melospiza vs bird genus

Melospiza and bird genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Melospiza	Yes	No	No	No
bird genus	Yes	No	No	No

As nouns, bird genus is a hypernym of Melospiza; that is, bird genus is a word with a broader meaning than Melospiza:

Melospiza (noun)	bird genus (noun)
American song sparrow and swamp sparrow	a genus of birds