brush turkey vs mound-bird

brush turkey and mound-bird both are nouns.

Word	Noun	Adjective	Verb	Adverb
brush turkey	Yes	No	No	No
mound-bird	Yes	No	No	No

As nouns, mound-bird is a hypernym of brush turkey; that is, mound-bird is a word with a broader meaning than brush turkey:

brush turkey: black megapode of wooded regions of Australia and New Guinea
mound-bird: large-footed short-winged birds of Australasia; build mounds of decaying vegetation to incubate eggs

Other hypernyms of brush turkey include megapode, mound bird, mound builder, scrub fowl.

brush turkey (noun)	mound-bird (noun)
black megapode of wooded regions of Australia and New Guinea	large-footed short-winged birds of Australasia; build mounds of decaying vegetation to incubate eggs