blackcap vs Parus atricapillus

blackcap and Parus atricapillus both are nouns.

Word	Noun	Adjective	Verb	Adverb
blackcap	Yes	No	No	No
Parus atricapillus	Yes	No	No	No

As nouns, blackcap and Parus atricapillus are synonyms defined as:

Other synonyms of blackcap include black-capped chickadee.

blackcap (noun)	Parus atricapillus (noun)
small brownish-grey warbler with a black crown	chickadee having a dark crown
chickadee having a dark crown
small black-headed European gull
raspberry native to eastern North America having black thimble-shaped fruit