family Rallidae vs bird family

family Rallidae and bird family both are nouns.

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

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

family Rallidae: rails; crakes; gallinules; coots
bird family: a family of warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings

family Rallidae (noun)	bird family (noun)
rails; crakes; gallinules; coots	a family of warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings