moa vs ratite

moa and ratite both are nouns.

Word	Noun	Adjective	Verb	Adverb
moa	Yes	No	No	No
ratite	Yes	No	No	No

As nouns, ratite is a hypernym of moa; that is, ratite is a word with a broader meaning than moa:

moa: extinct flightless bird of New Zealand
ratite: flightless birds having flat breastbones lacking a keel for attachment of flight muscles: ostriches, cassowaries, emus, moas, rheas, kiwis, elephant birds

Other hypernyms of moa include flightless bird, ratite bird.

moa (noun)	ratite (noun)
extinct flightless bird of New Zealand	flightless birds having flat breastbones lacking a keel for attachment of flight muscles: ostriches, cassowaries, emus, moas, rheas, kiwis, elephant birds