family Sulidae vs bird family

family Sulidae and bird family both are nouns.

Word	Noun	Adjective	Verb	Adverb
family Sulidae	Yes	No	No	No
bird family	Yes	No	No	No

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

family Sulidae: gannets and boobies
bird family: a family of warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings

family Sulidae (noun)	bird family (noun)
gannets and boobies	a family of warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings