Calidris canutus vs grayback

Calidris canutus and grayback both are nouns.

Word	Noun	Adjective	Verb	Adverb
Calidris canutus	Yes	No	No	No
grayback	Yes	No	No	No

As nouns, Calidris canutus and grayback are synonyms defined as:

Calidris canutus and grayback: a sandpiper that breeds in the Arctic and winters in the Southern Hemisphere

Other synonyms of Calidris canutus include greyback, knot.

Calidris canutus (noun)	grayback (noun)
a sandpiper that breeds in the Arctic and winters in the Southern Hemisphere	a dowitcher with a grey back
	a sandpiper that breeds in the Arctic and winters in the Southern Hemisphere