Duikers have a secretive nature, and this, combined with its dense, fairly inaccessible habitat, means that little is known about the behaviour of the yellow-backed duiker (4) (5). It is thought to be mainly solitary, or living in monogamous pairs, in spaced out territories (2) (4), and may be active by both day and night (5) (8). If the yellow-backed duiker comes across any danger, such as a predator, it will freeze immediately and the hairs in the yellow patch may erect (4) (5); possibly as a clear, visual, alarm signal to other yellow-backed duikers, or as a ‘predator invitation signal’ which causes a predator to strike too early, giving the duiker a chance to escape (4) (6) (8).
The yellow-backed duiker feeds on a wide range of vegetation, including fruits, leaves, shoots, seeds, bark and buds, and it may also occasionally eat carrion. In captivity a yellow-backed duiker was observed capturing, killing and eating a pigeon (4), and the species has also been recorded eating lizards and even tortoises (5). Yellow-backed duikers are believed to give birth to one calf a year after a gestation period of 151 days. The newborn lies up in vegetation for a week or so, but begins eating solid food very quickly (2), and is fully weaned by four to six weeks of age. The newborn is uniformly brownish-black in colour, with the horns and the characteristic yellow rump only developing after seven months or so (4) (5) (8). The yellow-backed duiker may live for more than 10 years in captivity (8).