Strix nebulosa vs great grey owl

Strix nebulosa and great grey owl both are nouns.

Word	Noun	Adjective	Verb	Adverb
Strix nebulosa	Yes	No	No	No
great grey owl	Yes	No	No	No

As nouns, Strix nebulosa and great grey owl are synonyms defined as:

Strix nebulosa and great grey owl: large dish-faced owl of northern North America and western Eurasia

Other synonyms of Strix nebulosa include great gray owl.

Strix nebulosa (noun)	great grey owl (noun)
large dish-faced owl of northern North America and western Eurasia	large dish-faced owl of northern North America and western Eurasia