New black colobus monkey with orange mask discovered in Congo Basin, immediately proposed as endangered
Genetic, anatomical and acoustic analyses have confirmed Colobus congoensis as a distinct species after an initial 2008 sighting proved inconclusive. The primate, known locally as 'Likweli', faces immediate threats from hunting and habitat loss.
A new species of colobus monkey has been scientifically described in the Congo Basin, 18 years after researchers first photographed it in a remote rainforest region. The confirmation, published in the journal PLOS One on 15 July 2026, crowns a lengthy investigation that accelerated after a second sighting in 2018.
A masked face and a distinctive call
The monkey has glossy black fur, a long curved tail and a bright orange-cream patch around its mouth and nose. Local inhabitants of the Congo Basin call it 'Likweli'. Its scientific name is Colobus congoensis.
The discovery of Colobus congoensis is both a scientific triumph and a sobering reminder that some of the rarest life forms on Earth could disappear before the world even knows of their existence.
Weighing about seven kilograms, the new species is smaller than related colobus monkeys. It also emits deep, resonant calls with a distinct acoustic structure, setting it apart from other African colobus species. The striking mask-like face distinguishes it from all previously known colobus monkeys.
Eighteen years from photograph to proof
A photograph taken in 2008 was not conclusive enough to declare a separate species. A decade later, a renewed sighting prompted genetic, anatomical and acoustic studies that have now confirmed the primate as distinct. Its closest relative is the black colobus (Colobus satanas), although the two are separated by more than 1,200 kilometres of rainforest.
The international research team involved scientists from Florida Atlantic University, the Lukuru Wildlife Research Foundation, Yale University, the City University of New York, Lomami National Park and the Frankfurt Zoological Society.
114 sightings across a tiny range
Between 2018 and 2022 the team recorded 114 sightings in an estimated range of just 1,700 square kilometres, an unusually small area for colobus monkeys. The species appears naturally isolated by rivers and forest edges. Researchers also spoke with villagers and hunters in rainforest settlements to learn about the monkey's distribution and behaviour; locals described it as shy and rarely seen.
- First photograph taken in a remote Congo Basin rainforest region, but insufficient to prove a distinct species.
- Renewed sighting triggers genetic, anatomical and acoustic investigations by an international research team.
- 114 sightings recorded across an estimated 1,700 sq km range; researchers interview local inhabitants and hunters.
- Colobus congoensis formally described as a new species in PLOS One; team proposes immediate IUCN endangered listing.
Immediate push for endangered status
The species lives in a limited area of the Democratic Republic of the Congo and is exposed to hunting pressure and habitat loss. The research team has proposed placing Colobus congoensis on the IUCN Red List as critically endangered immediately.
A reminder of unexplored biodiversity
Co-author John Hart of the Lukuru Wildlife Research Station noted that even in regions already scientifically explored, entirely new species continue to be found. He said the discovery shows how much biodiversity in the central Congo Basin remains unexplored and how the region continues to shape understanding of primate evolution and conservation.
Only a handful of new African monkey species have been discovered in the past 75 years. The find places fresh attention on the species-rich Congo Basin at a moment when the newly described primate already faces an uncertain future.
