blacktail deer vs mule deer

blacktail deer and mule deer both are nouns.

Word	Noun	Adjective	Verb	Adverb
blacktail deer	Yes	No	No	No
mule deer	Yes	No	No	No

As nouns, mule deer is a hypernym of blacktail deer; that is, mule deer is a word with a broader meaning than blacktail deer:

blacktail deer: mule deer of western Rocky Mountains
mule deer: long-eared deer of western North America with two-pronged antlers

Other hypernyms of blacktail deer include burro deer, Odocoileus hemionus.

blacktail deer (noun)	mule deer (noun)
mule deer of western Rocky Mountains	long-eared deer of western North America with two-pronged antlers