mound builder vs mound bird

mound builder and mound bird both are nouns.

Word	Noun	Adjective	Verb	Adverb
mound builder	Yes	No	No	No
mound bird	Yes	No	No	No

As nouns, mound builder and mound bird are synonyms defined as:

mound builder and mound bird: large-footed short-winged birds of Australasia; build mounds of decaying vegetation to incubate eggs

Other synonyms of mound builder include megapode, mound-bird, scrub fowl.

mound builder (noun)	mound bird (noun)
large-footed short-winged birds of Australasia; build mounds of decaying vegetation to incubate eggs	large-footed short-winged birds of Australasia; build mounds of decaying vegetation to incubate eggs