Aythya affinis vs lesser scaup

Aythya affinis and lesser scaup both are nouns.

Word	Noun	Adjective	Verb	Adverb
Aythya affinis	Yes	No	No	No
lesser scaup	Yes	No	No	No

As nouns, Aythya affinis and lesser scaup are synonyms defined as:

Aythya affinis and lesser scaup: common scaup of North America; males have purplish heads

Other synonyms of Aythya affinis include lake duck, lesser scaup duck.

Aythya affinis (noun)	lesser scaup (noun)
common scaup of North America; males have purplish heads	common scaup of North America; males have purplish heads