black-tailed deer vs blacktail deer

black-tailed deer and blacktail deer both are nouns.

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

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

black-tailed deer and blacktail deer: mule deer of western Rocky Mountains

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

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