Large African antelope (5)
(Other definitions for bongo that I've seen before include "Rare African antelope" , "Small drum played with hands" , "Drum between the knees" , "Type of drum - central African antelope" , "One of a pair of drums" .)
'large african antelope' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for eland that I've seen before include "Browser" , "Spiral-horn antelope" , "game animal" , "Ruminant" , "Large African antelope with spiral horns" .)
(Other definitions for hartebeest that I've seen before include "African native" , "wild animal" , "Creature" , "antelope" , "Game" .)