yellowbird vs New World warbler

yellowbird and New World warbler both are nouns.

Word	Noun	Adjective	Verb	Adverb
yellowbird	Yes	No	No	No
New World warbler	Yes	No	No	No

As nouns, New World warbler is a hypernym of yellowbird; that is, New World warbler is a word with a broader meaning than yellowbird:

yellowbird: yellow-throated American wood warbler
New World warbler: small bright-colored American songbird with a weak unmusical song

Other hypernyms of yellowbird include wood warbler.

yellowbird (noun)	New World warbler (noun)
American finch whose male has yellow body plumage in summer	small bright-colored American songbird with a weak unmusical song
yellow-throated American wood warbler