stonechat vs Saxicola torquata

stonechat and Saxicola torquata both are nouns.

Word	Noun	Adjective	Verb	Adverb
stonechat	Yes	No	No	No
Saxicola torquata	Yes	No	No	No

As nouns, stonechat and Saxicola torquata are synonyms defined as:

stonechat and Saxicola torquata: common European chat with black plumage and a reddish-brown breast

stonechat (noun)	Saxicola torquata (noun)
common European chat with black plumage and a reddish-brown breast	common European chat with black plumage and a reddish-brown breast