LOMAMI NATIONAL PARK — Researchers have formally identified a new species of monkey, Colobus congoensis, in the Democratic Republic of the Congo, marking the fifth African monkey species discovered in the last 75 years. The findings, published in the journal PLOS ONE on July 15, 2024, describe a primate with unique physical, vocal, and genetic traits found exclusively in Lomami National Park and its immediate surroundings.

The monkey, known locally as "Likweli" by the Balanga people, is distinguished by glossy black fur, a vivid orange patch encircling its mouth and nose, bare gray skin on its cheekbones, and a contrasting white patch of fur around its rump. It weighs approximately 15 pounds (6.8 to 7 kilograms), is smaller than related Colobus monkeys, and features long fur, a sweeping tail, and large folded ears. Colobus congoensis also lacks thumbs—a trait shared among all Colobus monkeys—and lives in social groups ranging from one to 20 individuals.

One of the most defining behavioral characteristics of the species is its vocalization: Colobus congoensis produces deep, loud roars and snorts that researchers say clearly differentiate it from other Colobus monkeys. This acoustic signature, combined with its physical appearance, initially raised questions about its taxonomic status. Conservationists first captured a partially obscured photograph of the animal in Lomami National Park in 2008, but it wasn’t until clearer images emerged in 2018 that scientists launched a formal investigation into whether it represented a previously unknown species.

From 2018 to 2022, researchers documented 114 sightings of the monkey in its natural habitat. To assess local knowledge, they showed photographs to residents of 52 villages surrounding Lomami National Park; only eight villages recognized the animal. Some members of the Mituku communities refer to it as "kasaba nkoni," meaning "the branch shaker," likely referencing its movement through the canopy. The species’ limited recognition even among nearby communities underscores its elusive nature and restricted distribution.

Researchers confirmed the species’ distinct status through genetic analysis, sequencing DNA from confiscated specimens and comparing it with historical samples in museum collections. The data revealed that Colobus congoensis is most closely related to the black colobus (Colobus satanas), which inhabits forests approximately 750 miles (1,200 kilometers) to the west in Cameroon, Gabon, and Bioko Island. Genetic evidence indicates the two species diverged between 3.44 million and 5.78 million years ago. Additionally, morphological studies identified distinctive cranial, dental, and skeletal characteristics that separate Colobus congoensis from every other known African colobus monkey.

Joshua Linder, anthropologist and president of The Forest Collective, emphasized the rarity of the discovery: "It’s not very common these days to find a new, never-before-documented primate species, let alone a relatively large species of monkey." Kate Detwiler, professor of biological sciences at Florida Atlantic University and a co-author of the study, added that "the discovery is reshaping our understanding of African monkey evolution." Junior Amboko, a doctoral student at Florida Atlantic University and co-corresponding author of the study, contributed significantly to the field and genetic work underpinning the identification.

Despite the excitement surrounding the discovery, researchers express grave concerns about the species’ future. They estimate its geographic range at just 650 to 660 square miles (1,700 square kilometers)—a highly restricted area already facing pressure from deforestation and hunting. Colobus monkeys, as herbivores, play a critical role in seed processing and forest regeneration, making their conservation ecologically significant. Based on these threats, the research team recommends that Colobus congoensis be classified as endangered.

Thomas Gillespie, ecologist at Emory University, offered a tempered perspective: "It’s very exciting, but also very sobering to be finding a new species of primate when tropical forests are under so much stress right now." Similarly, Alexander Georgiev, senior lecturer in primatology at Bangor University, noted, "Finding a new monkey species that is not only unknown to science but is also little known to the people that live where it occurs is very rare and exciting indeed." Christopher Gilbert, professor of anthropology at the CUNY Graduate Center and Hunter College, stressed the rigor required for such claims: "When a potential new species is discovered, the evidence has to be overwhelming."

The identification of Colobus congoensis highlights both the biological richness of the Congo Basin and the fragility of its ecosystems. As one of only five new African monkey species documented since 1949, its discovery underscores how much remains unknown in remote tropical forests—even as those habitats shrink. The species’ extremely limited range and exposure to hunting and habitat loss mean immediate conservation action is necessary to prevent its disappearance before it becomes widely known.

Formal recognition in a peer-reviewed journal like PLOS ONE provides the scientific foundation for conservation prioritization. With researchers urging an endangered classification, the next steps will likely involve assessments by the International Union for Conservation of Nature and potential integration of Colobus congoensis into regional and national protection strategies within the Democratic Republic of the Congo.