heron vs wader

heron and wader both are nouns.

Word	Noun	Adjective	Verb	Adverb
heron	Yes	No	No	No
wader	Yes	No	No	No

As nouns, wader is a hypernym of heron; that is, wader is a word with a broader meaning than heron:

heron: grey or white wading bird with long neck and long legs and (usually) long bill
wader: any of many long-legged birds that wade in water in search of food

Other hypernyms of heron include wading bird.

heron (noun)	wader (noun)
grey or white wading bird with long neck and long legs and (usually) long bill	any of many long-legged birds that wade in water in search of food