Elaphurus davidianus vs deer

Elaphurus davidianus and deer both are nouns.

Word	Noun	Adjective	Verb	Adverb
Elaphurus davidianus	Yes	No	No	No
deer	Yes	No	No	No

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

Elaphurus davidianus: large Chinese deer surviving only in domesticated herds
deer: distinguished from Bovidae by the male's having solid deciduous antlers

Other hypernyms of Elaphurus davidianus include cervid.

Elaphurus davidianus (noun)	deer (noun)
large Chinese deer surviving only in domesticated herds	distinguished from Bovidae by the male's having solid deciduous antlers