waterbuck vs Kobus kob

waterbuck and Kobus kob both are nouns.

Word	Noun	Adjective	Verb	Adverb
waterbuck	Yes	No	No	No
Kobus kob	Yes	No	No	No

As nouns, Kobus kob is a hyponym of waterbuck; that is, Kobus kob is a word with a more specific, narrower meaning than waterbuck:

waterbuck: any of several large African antelopes of the genus Kobus having curved ridged horns and frequenting e.g. swamps and rivers
Kobus kob: an orange-brown antelope of southeast Africa

Other hyponyms of waterbuck include kob, Kobus leche, lechwe.

waterbuck (noun)	Kobus kob (noun)
any of several large African antelopes of the genus Kobus having curved ridged horns and frequenting e.g. swamps and rivers	an orange-brown antelope of southeast Africa