Oustalet’s or Semliki? That is the question. It may not be on everyone’s lips, but it’s uppermost in the minds of conservationists after a rare red colobus monkey triggered a camera trap several hundred miles outside its known range.
The image was captured in a remote forest in South Sudan as part of the extensive and ongoing camera-trap surveys that began in 2015 as a collaboration between Fauna & Flora International (FFI), Bucknell University and the South Sudanese government.
Even for seasoned primatologists, Oustalet’s red colobus – the Central African version of these acrobatic, fiery-coated monkeys – is a riddle, wrapped in a mystery inside an enigma. A remarkable 20 subspecies of this highly variable species have been described, according to The Kingdon Field Guide to African Mammals.
These include the version known to its close friends as the Semliki red colobus, named after the river valley in Central Africa where an isolated population was first recorded, and which may or may not turn out to be a separate species.