black-tailed deer vs blacktail

black-tailed deer and blacktail both are nouns.

Word	Noun	Adjective	Verb	Adverb
black-tailed deer	Yes	No	No	No
blacktail	Yes	No	No	No

As nouns, black-tailed deer and blacktail are synonyms defined as:

Other synonyms of black-tailed deer include blacktail deer, Odocoileus hemionus columbianus.

black-tailed deer (noun)	blacktail (noun)
mule deer of western Rocky Mountains	mule deer of western Rocky Mountains