warbler vs wood warbler

warbler and wood warbler both are nouns.

Word	Noun	Adjective	Verb	Adverb
warbler	Yes	No	No	No
wood warbler	Yes	No	No	No

As nouns, wood warbler is a hyponym of warbler; that is, wood warbler is a word with a more specific, narrower meaning than warbler:

warbler: a small active songbird
wood warbler: small bright-colored American songbird with a weak unmusical song

warbler (noun)	wood warbler (noun)
a small active songbird	small bright-colored American songbird with a weak unmusical song
a singer; usually a singer who adds embellishments to the song	European woodland warbler with dull yellow plumage