genus Nymphicus vs bird genus

genus Nymphicus and bird genus both are nouns.

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

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

genus Nymphicus: a genus of Psittacidae containing the cockatiel, quarrion, or weiro (Nymphicus)
bird genus: a genus of birds

genus Nymphicus (noun)	bird genus (noun)
a genus of Psittacidae containing the cockatiel, quarrion, or weiro (Nymphicus)	a genus of birds