wading bird vs bustard

wading bird and bustard both are nouns.

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

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

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

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