bustard vs Otis tarda

bustard and Otis tarda both are nouns.

Word	Noun	Adjective	Verb	Adverb
bustard	Yes	No	No	No
Otis tarda	Yes	No	No	No

As nouns, Otis tarda is a hyponym of bustard; that is, Otis tarda is a word with a more specific, narrower meaning than bustard:

bustard: large heavy-bodied chiefly terrestrial game bird capable of powerful swift flight; classified with wading birds but frequents grassy steppes
Otis tarda: largest European land bird

Other hyponyms of bustard include great bustard, Choriotis australis, plain turkey.

bustard (noun)	Otis tarda (noun)
large heavy-bodied chiefly terrestrial game bird capable of powerful swift flight; classified with wading birds but frequents grassy steppes	largest European land bird