genus Cathartes vs bird genus

genus Cathartes and bird genus both are nouns.

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

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

genus Cathartes (noun)	bird genus (noun)
type genus of the Cathartidae: turkey vultures	a genus of birds