How scientists tracked down a new monkey species in the Congo rainforest

A Decade-Long Mystery in Lomami National Park

The discovery of Colobus congoensis, known by the common name likweli in the local Kilanga language, concludes a search that began in 2008. In that year, conservationists working in the dense rainforests of Lomami National Park, located within the Congo Basin in the DRC, captured a blurry photograph of an unidentified monkey. While it resembled monkeys of the genus Colobus, its small size, glossy black fur, dramatic facial features, and white rear-end markings set it apart from any known species. The animal was partially obscured, and without additional observations, scientists turned their attention to other species.

The trail went cold until 2018, when researchers working near the location of the 2008 sighting spotted the monkey again. This time, they obtained much clearer photos. Junior Amboko, a field conservationist from the Democratic Republic of the Congo and a PhD student at Florida Atlantic University, oversaw the field researchers at the time. We were able to tell that it was something unusual, Amboko told Gizmodo. The photos revealed that the monkey did not have thumbs, confirming that it belonged to the genus Colobus, but its bizarre features—particularly the pinkish-orange patch around its mouth and nose—were a clear sign to researchers that they had encountered a unique animal.

Genetic Confirmation and Scientific Significance

The formal description of the monkey was published in a new paper in PLOS One. Researchers confirmed through genetic analyses that C. congoensis is a new species. It is closely related to its sister species, the black colobus. Joshua Linder, an anthropologist and president and co-founder of The Forest Collective, a nonprofit that aims to conserve and restore tropical rainforests, noted the rarity of the find. “This is remarkable because it’s not very common these days to find a new, never-before-documented primate species, let alone a relatively large species of monkey,” Linder said.

The monkey is relatively small, with adults typically weighing about 15 pounds (seven kilograms). Beyond its physical appearance, the species is known for making unique roars and snorting sounds. Scientists behind the study suggested that there might be more unknown monkey species in the region.

Context of African Primate Research

The identification of C. congoensis highlights the ongoing efforts to document biodiversity in the Congo Basin. In a separate, distinct effort to document rare primates in the region, researchers Lieven Devreese of Belgium and Gaël Elie Gnondo Gobolo of the Republic of the Congo led an expedition in February to track the Bouvier’s red colobus monkey, a species previously thought to be extinct since the 1970s. That expedition, supported by the Wildlife Conservation Society and crowdfunding through Indiegogo, resulted in the first-ever photos of the red primate. “Our photos are the world’s first [of the monkey], and confirm that the species is not extinct,” Devreese said in a statement regarding that specific research.

The discovery of Colobus congoensis serves as a reminder of the scientific potential remaining in the dense forests of the DRC. As researchers continue to analyze the local fauna, the identification of the likweli stands as a significant milestone in primate taxonomy, confirming that even in well-studied genera, there remain mysteries waiting to be uncovered in the heart of the Congo Basin.

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