hooded merganser vs hooded sheldrake

hooded merganser and hooded sheldrake both are nouns.

Word	Noun	Adjective	Verb	Adverb
hooded merganser	Yes	No	No	No
hooded sheldrake	Yes	No	No	No

As nouns, hooded merganser and hooded sheldrake are synonyms defined as:

hooded merganser and hooded sheldrake: small North American duck with a high circular crest on the male's head

Other synonyms of hooded merganser include Lophodytes cucullatus.

hooded merganser (noun)	hooded sheldrake (noun)
small North American duck with a high circular crest on the male's head	small North American duck with a high circular crest on the male's head