Researchers have confirmed a small, elusive African monkey with a distinctive orange patch around its mouth and a deep, frog-like call as a brand-new species, named Colobus congoensis, marking only the fifth new African monkey identified in the past 75 years.
Science has a new primate to catalog in the Democratic Republic of the Congo. Formally described in a study published in PLOS One, Colobus congoensis—widely known to local communities as the Likweli—represents a major taxonomic addition to the continent’s biodiversity.
Adult specimens typically weigh about 15 pounds, equivalent to roughly seven kilograms. Beyond their size, the primates are instantly recognizable by a striking orange cream patch
surrounding their mouths, paired with a thatch of fine white hair on their rear ends, according to the study authors.
Nearly Two Decades From a Blurry Photo to Formal Discovery
The journey to confirming the new primate began back in 2008. During an expedition in a remote rainforest, a research crew captured the first known photograph of the animal from behind. The image showed a dark monkey with a strange appearance, but because it was blurry, scientists could not determine whether it represented an entirely new species or a known variant.
Junior Amboko, a co-author of the study and a doctoral student in the Department of Biological Sciences at Florida Atlantic University, explained the initial encounter. The discovery started by chance in 2008, when researchers working in a remote rainforest in the Democratic Republic of the Congo took a partially blurred photo of a strange monkey, he noted.
For nearly a decade, the animal remained a mystery. A breakthrough arrived in 2018 when scientists encountered the monkey again, capturing clearer photographs that spurred a detailed investigation. Teams gathered museum specimens of skulls and fur, recorded distinct audio calls, and consulted local communities who already recognized the creature by the name Likweli. In 2020, researchers launched the dedicated Likweli Project to formally classify the animal, collecting further images, sound recordings, and tissue samples from monkeys recovered from illegal hunting activities in Lomami National Park.
Genetic Divergence and a Froglike Roar
Field observations alone were not enough to secure formal recognition. To confirm the classification, researchers combined anatomical comparisons with genetic sequencing. The results astonished the scientific team.
Kate Detwiler, senior author and associate professor of biological sciences at Florida Atlantic University, stated that they were shocked by the genetic data because it revealed such a strong signal of deep divergence.
DNA analysis revealed that the lineage split from its closest relative, the black colobus (Colobus satanas), at least 4 million years ago. Anatomically, skull comparisons confirmed the monkey is smaller than its sister species. Like other members of the colobus genus, C. congoensis lacks thumbs, yet its facial mask and low, resonant calls set it apart. To the untrained ear, the animal’s vocalization sounds somewhat like a frog or a snorting pig.
Researchers attribute the long delay in formal discovery to the extreme isolation of the region. The primate inhabits the remote territory nestled between the Lomami and Congo (Lualaba) rivers in east-central DR Congo, a dense equatorial environment where rivers and thick rainforests naturally separate wildlife and make fieldwork exceptionally difficult.
Conservation Stakes for the Newly Named Primate
Even as it joins the scientific record, the newly confirmed species faces immediate survival pressures. Its known geographic range spans only about 650 square miles, equivalent to roughly 1,700 square kilometers, and population numbers remain low due to human population growth and illegal hunting for bushmeat.
Because most of its habitat falls within Lomami National Park, study authors have urged the International Union for Conservation of Nature to officially list the species as endangered. Protecting the park and enlisting local residents are seen as vital steps for survival.
Study authors noted that protecting Lomami National Park, where the majority of the C. congoensis range is located, and engaging local communities to refrain from hunting the species are the most crucial actions required to ensure the conservation of C. congoensis.
Broader conservation efforts across the region are also expanding through a newly launched corridor designed to connect protected areas throughout the Congo Basin, offering a guarded pathway for a species that managed to hide in plain sight for generations.