bustard vs plain turkey

bustard and plain turkey both are nouns.

Word	Noun	Adjective	Verb	Adverb
bustard	Yes	No	No	No
plain turkey	Yes	No	No	No

As nouns, plain turkey is a hyponym of bustard; that is, plain turkey 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
plain turkey: popular Australian game bird

Other hyponyms of bustard include great bustard, Otis tarda, Choriotis australis.

bustard (noun)	plain turkey (noun)
large heavy-bodied chiefly terrestrial game bird capable of powerful swift flight; classified with wading birds but frequents grassy steppes	popular Australian game bird