bustard vs wading bird

bustard and wading bird both are nouns.

Word	Noun	Adjective	Verb	Adverb
bustard	Yes	No	No	No
wading bird	Yes	No	No	No

As nouns, wading bird is a hypernym of bustard; that is, wading bird is a word with a broader meaning than bustard:

bustard: large heavy-bodied chiefly terrestrial game bird capable of powerful swift flight; classified with wading birds but frequents grassy steppes
wading bird: any of many long-legged birds that wade in water in search of food

Other hypernyms of bustard include wader.

bustard (noun)	wading bird (noun)
large heavy-bodied chiefly terrestrial game bird capable of powerful swift flight; classified with wading birds but frequents grassy steppes	any of many long-legged birds that wade in water in search of food