Scientists have described a new species of colobus monkey in the forests of the Democratic Republic of Congo (DRC), report John Hart at Lukuru Wildlife Research Foundation and colleagues on July, 2026 in the open access journal PLOS One.
The first hint that a new primate species might be hiding in the dense forests of Lomami National Park came in 2008, when conservationists photographed an unidentified monkey during an expedition. After a second sighting in 2018, researchers embarked on a dedicated mission to find and describe the mysterious monkey.
The new species, which has been given the scientific name Colobus congoensis and the common name 'Likweli' (the name used by local communities), has physical and behavioral characteristics that set it apart from other colobus species. Although mainly black in color, Likweli have a conspicuous orange patch around the mouth and bare grey skin on their cheek bones contrasting with black skin around the eyes, resembling a mask. They also have a distinctive patch of white fur around the anus. Likweli produce loud vocalizations called 'roars', punctuated by distinctive snorts. Their orange lips make these roars visually, as well as audibly, striking.
Field surveys revealed that the species occupies at least 1700 square kilometers of closed-canopy forest between the Lomami and Lilo rivers in the DRC. Their range size is believed to be a fraction of that of most other colobus monkeys, suggesting that Likweli may be very sensitive to habitat quality. The species was usually observed in small groups, often alongside other monkey species. Given their small geographic range and population size, the researchers recommend classifying the species as Endangered on the IUCN Red List.
Morphological and genetic analysis showed that Likweli are most closely related to black colobus monkeys (Colobus satanas), even though the two species are separated by over 1200 kilometers of forest. The researchers estimate that they diverged between 5.78 and 3.44 million years ago, representing a much earlier split than other species in the genus.
Colobus congoensis is only the fifth new species of African monkey to be described in the last 75 years. The discovery highlights the importance of DRC's Lomami National Park for primate conservation. However, the species' already restricted habitat could come under threat as human populations expand in the coming decades, so its protection is a top conservation priority, the authors say.
Junior Amboko, co-corresponding author, Ph.D. student in the Department of Biological Sciences at Florida Atlantic University, National Geographic Explorer, and Lomami National Park researcher, adds: "I was fortunate to be part of this discovery from the very beginning – from recognizing in the first photographs that we were looking at something new in the forest, to training field teams to document its behavior, analyzing the data and helping write the scientific paper. Being involved through every stage, from fieldwork to the lab, made this an especially rewarding experience. It makes it even more meaningful that the name I proposed, Colobus congoensis, was chosen. The name honors the Democratic Republic of Congo, a country with extraordinary biodiversity, and reflects the incredible natural heritage that continues to reveal new discoveries. I hope it also draws greater attention to the importance of conserving these forests and the unique species that call them home."
Kate Detwiler, Ph.D., senior and corresponding author and an associate professor of biological sciences at Florida Atlantic University, adds: "What makes Colobus congoensis such an important discovery is that the evidence for it being a distinct species came from several independent sources. Field observations first suggested that these monkeys were unusual, detailed anatomical comparisons showed they differed from other known colobus monkeys, and genetic analyses revealed that they have been evolving separately from their closest relatives for roughly 4 to 5 million years. When those lines of evidence all pointed to the same conclusion, it became clear that we were looking at a previously undescribed primate species. Discovering a new monkey species is extraordinarily rare, and it highlights how much remains to be documented in the Congo Basin and how urgent it is to protect the small area where this species is found."
John A. Hart, first author and a conservation scientist with the Lukuru Wildlife Research Foundation, adds: "We continue to be reminded that the Congo Basin remains one of the world's last great frontiers for mammal discovery. Even in regions that have been scientifically explored, entirely new species are still coming to light. This discovery reinforces how much biodiversity remains undocumented in the Central Congo Basin and how this region continues to reshape our understanding of primate evolution and conservation."
Author interview: https://plos.io/4f5k7IC
In your coverage, please use this URL to provide access to the freely available article in PLOS One: https://plos.io/4wvCq0I
Citation: Hart JA, Amboko JD, Arenson JL, Horton ER, Coates KF, Kapale J-PI, et al. (2026) Likweli: A remarkable new species of Colobus monkey from the Lomami National Park, Democratic Republic of Congo. PLoS One 21(7): e0349857. https://doi.org/10.1371/journal.pone.0349857
Author countries: USA, Democratic Republic of Congo.
Funding: Funding for the field study of Likweli in the Lomami National Park was provided by the National Geographic Society (NGS-74097C-20), US Fish and Wildlife Service, Frankfurt Zoological Society, The Lukuru Wildlife Research Foundation, Wildcat Foundation, and Arcus Foundation. Funding from Full Circle Foundation and Rainforest Trust supported surveys in the buffer zone. Funding to support the morphological analysis was generously provided by the Yale Peabody Museum W. R. Coe Fund, Yale Institute for Biospheric Studies, the American Association of Physical Anthropologists Professional Development Program, the PSC-CUNY Faculty Award Program, the Hunter College Presidential Travel Award Program, the National Science Foundation (SBE 40F79-02 04 and SBE 2018093), the Leakey Foundation, and the Graduate Center, CUNY. Funding for the molecular analysis was provided by the Primatology Lab, FAU Foundation, Inc. at Florida Atlantic University. There was no additional external funding received for this study.
