ant thrush vs ant bird

ant thrush and ant bird both are nouns.

Word	Noun	Adjective	Verb	Adverb
ant thrush	Yes	No	No	No
ant bird	Yes	No	No	No

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

ant thrush: a kind of antbird, with species spanning the genera Formicarius and Chamaeza
ant bird: any of various dull-colored South American birds that feeding on ants some following army ant swarms

Other hypernyms of ant thrush include antbird.

ant thrush (noun)	ant bird (noun)
a kind of antbird, with species spanning the genera Formicarius and Chamaeza	any of various dull-colored South American birds that feeding on ants some following army ant swarms