Aythya marila vs scaup

Aythya marila and scaup both are nouns.

Word	Noun	Adjective	Verb	Adverb
Aythya marila	Yes	No	No	No
scaup	Yes	No	No	No

As nouns, scaup is a hypernym of Aythya marila; that is, scaup is a word with a broader meaning than Aythya marila:

Aythya marila: large scaup of North America having a greenish iridescence on the head of the male
scaup: diving ducks of North America having a bluish-grey bill

Other hypernyms of Aythya marila include bluebill, broadbill, scaup duck.

Aythya marila (noun)	scaup (noun)
large scaup of North America having a greenish iridescence on the head of the male	diving ducks of North America having a bluish-grey bill