[8] Dependent on geographical location, their soft dense coats can range from a pale gray to light or dark brown.

The variation is consistent with evolutionary development to aid with camouflage, so that in wetter regions with more verdant and abundant vegetation, they are darker, and in more arid areas, their colouring is lighter.

In one South African forest, their principal foods were Schotia latifolia, Cassine aethiopica, and Eugenia natalensis.

[12] In D. validus, it starts with a series of loud, measured cracking sounds, sometimes compared to "a huge gate with rusted hinges being forced open".

Females also call, but lack the air pouches and enlarged larynges of the males, producing only a feeble imitation.