The Ader's Duiker (Cephalophus adersi also known as Nunga in Swahili, Kunga marara in Kipokomo and Harake in Giriama ) is a small forest dwelling Duiker found only on Zanzibar and in a small coastal enclave in Kenya. It is believed by some to be a subspecies of the Red , Harvey's , or Peter's Duiker or a subspecies of a combination of the above.

Ader's Duiker stand around 30 centimetres tall at the shoulder. Their weight varies greatly depending on geographical location, those in eastern Zanzibar weigh 12 kilograms, while those in the south weigh only 7.5 kilograms. Ader's Duikers have a reddish-brown coat which is grayer on the neck and lighter down the backside and underneath. There is a small red crest running along the head. Ader's Duiker have small simple horns of 3 to 6 centimetres.

Ader's Duiker live in coastal forests and woodlands where they eat flowers, leaves and fruit which has fallen from the forest canopy. Ader's Duiker are diurnal, eating from dawn until noon, resting untill midafternoon when they become active again untill nightfall. They live in pairs and keep a small territory.

There are estimated to be around 1400 Ader's Duiker left in the world. They are threatened by habitat destruction, feral dogs and, particularly, over-hunting. Ader's Duiker is particularly sought due to its soft skin and sweet meat.