Carduelis spinus vs siskin

Carduelis spinus and siskin both are nouns.

Word	Noun	Adjective	Verb	Adverb
Carduelis spinus	Yes	No	No	No
siskin	Yes	No	No	No

As nouns, Carduelis spinus and siskin are synonyms defined as:

Carduelis spinus and siskin: small yellow-and-black Eurasian finch with a sharp beak

Carduelis spinus (noun)	siskin (noun)
small yellow-and-black Eurasian finch with a sharp beak	small yellow-and-black Eurasian finch with a sharp beak