grass finch vs Pooecetes gramineus

grass finch and Pooecetes gramineus both are nouns.

Word	Noun	Adjective	Verb	Adverb
grass finch	Yes	No	No	No
Pooecetes gramineus	Yes	No	No	No

As nouns, grass finch and Pooecetes gramineus are synonyms defined as:

grass finch and Pooecetes gramineus: common North American finch noted for its evening song

Other synonyms of grass finch include vesper sparrow.

grass finch (noun)	Pooecetes gramineus (noun)
usually brightly-colored Australian weaverbirds; often kept as cage birds	common North American finch noted for its evening song
common North American finch noted for its evening song