The first recorded sighting of me (by western civilization) was in the 5th century B.C. by a Roman explorer. I am a gentle and intelligent creature, I am more closely-related to humankind than many might expect.
What am I?
CLUE ONE: There are three subspecies of my species all living in different parts of Africa.
CLUE TWO: I am mainly ground-living, but where trees are strong enough and fruiting, I sometimes can be seen in them. I am a selective feeder that utilizes the fruits, stems, flowers, shoots, bulbs, bark, leaves and pith of over 200 plant species.
CLUE THREE: You may have seen me in the movie "Planet of the Apes."