A new and rare monkey species, named Colobus congoensis, was formally described by scientists after years of research in one of the most biodiverse areas of Central Africa. This primate, known locally as Likweli by the Balanga people, has a notable characteristic: its deep croaking resembles the sound of a frog.
The identification of this novel animal occurred after prolonged investigations. The first record of the monkey dates back to 2008, when researchers from the Lukuru Wildlife Research Foundation were on an expedition in the forest that is now part of Lomami National Park. At that time, a blurry photo of a black-furred monkey in the tree canopy was captured, raising suspicions about its uniqueness.
The animal remained unknown for ten years. In 2018, researcher Jean Pierre Kapale led a new patrol and obtained a clear photograph of the monkey, characterized by dark, disheveled fur, a very long tail, and pale markings around the mouth. This triggered a deeper investigation, resulting in seven additional photographs in the following months, which confirmed it was the same individual seen in 2008.
The searches extended until 2022, covering humid forests located between the Lomami and Congo (Lualaba) rivers, a biologically crucial region in Central Africa. A total of 114 observations were made in an area of approximately 1,700 km², comparable to the municipality of São Paulo.
Researchers consulted residents of 52 local villages regarding primates they recognized. The description of the rare species was provided in only eight of these villages. Among the Balanga, the name was Likweli, while in the Mituku communities, it was called kasaba nkoni, which means something like 'that which shakes the branches.'
Field observations indicated that the primate possessed four fingers on each hand, including small thumbs, suggesting it might belong to the subfamily of colobines, known for being social frugivorous monkeys. To prove its novelty, genetic tests were conducted in the laboratory using specimens seized from hunters by the National Park guards.
Genetic tests confirmed that the species belongs to the genus Colobus and revealed a relationship with Colobus satanas, which lives about 1,200 km away, in central-western Africa. The two species are believed to have diverged evolutionarily approximately four or five million years ago, coinciding with the similarity of their vocalizations.
Additionally, morphological analyses of the skull, teeth, and face helped confirm the new species. Scientists named the new monkey Colobus congoensis, in honor of the Congo Basin where it was found.
The Colobus congoensis is an animal covered in dark fur, which can appear shiny depending on the light. Its face features dark coloration, prominent facial contours, and intense black eyes, giving it the appearance of a mask. It has a long tail, large ears, and weighs just over 5 kilograms, making it lighter than other members of the genus Colobus.
Zoologists have discovered and described a new species of monkey belonging to the genus Colobus, which inhabits the jungles of eastern Democratic Republic of Congo. This species has been named likveli. Its distinction from other colobuses lies in its more compact size, the presence of orange lips, and a white patch around the anus.
Genetic studies have established that likvelis belong to an evolutionary branch that separated approximately four to five million years ago. Unfortunately, due to their limited range, as well as deforestation and hunting, this new species is under threat of extinction. The results of this scientific investigation were published in PLoS One.
Although over 500 primate species are known to zoologists, discoveries continue, often by assigning the status of a separate species to already known populations based on genetic, morphological, and acoustic data. In recent times, the Skywalker howler, the Tapanuli orangutan, and Schneider's guenon have been discovered. Previously, in 2005, the monkey Rungwecebus kipunji, related to baboons, inhabiting the mountain forests of Tanzania, was described, and in 2012, the monkey Cercopithecus lomamiensis from the Democratic Republic of Congo was described.
John Hart of the Lukuru Nature Research Foundation and his team reported the discovery of another new primate species. The first evidence of its existence appeared in 2008 when researchers recorded a small long-tailed monkey in the jungles of eastern Democratic Republic of Congo that differed from all local species, although most of the animal in the picture was hidden by foliage. Between 2018 and 2019, after the creation of Lomami National Park in the area, these monkeys were sighted and photographed about ten times. These new images clearly show that they have black fur, elongated on the back and shoulders, and on the bare skin of the face, there are orange lips and a lip groove, as well as a gray 'mask' around the eyes and a white patch around the anus. This combination of coloration is not found in any known African primates.
From 2020 to 2022, Hart and his co-authors conducted in-depth research on these monkeys from Lomami. The team observed them, recording their sounds, and took three individuals for genetic and morphological analysis. The analysis showed that the Lomami monkeys belong to the genus Colobus (Colobus) of the family Cercopithecidae, but they differ from all described representatives of the genus in their coloration, smaller size (weighing about seven kilograms), skull structure, and vocalization method. They are most similar to black colobus monkeys (C. satanas) living approximately 1200 kilometers to the west, between Cameroon and Gabon. Nevertheless, the latter are larger, and they lack the orange markings on the lips and the white patch around the anus. Genetic comparison revealed that the Lomami monkeys and black colobus monkeys are sister evolutionary lineages that diverged about four to five million years ago.
The researchers decided to designate the Lomami monkeys as a separate species, naming it Colobus congoensis. Local residents use the vernacular name 'likweli', which the authors also recommend. However, surveys in the presumed habitat area showed that this species is known to the local population in only eight out of fifty-two locations. According to Hart and his colleagues' estimates, the likveli's range covers a limited area of about 1700 square kilometers on the right bank of the Lomami River. These monkeys live in dense jungles with tall trees on clay soil uplands, at an altitude of 406–490 meters above sea level, mainly near the Lomami River. The likvelis are almost constantly in the canopy, descending to the ground only rarely.
Between 2018 and 2022, 114 encounters with these primates were recorded. They move alone or in small groups (averaging 6.2 individuals), often accompanied by one to six other species of monkeys, such as Angolan colobus (C. angolensis) and red colobus Piliocolobus parmentieri. Based on dental structure, likvelis feed on fruits, leaves, and flowers, unlike their closest relatives, black colobus monkeys, which mainly consume seeds. Since likvelis are rarely encountered even within their limited range, researchers recommended assigning the species the endangered status (EN). The main threats to them remain deforestation and hunting. Given the rapid growth of the region's population, a significant reduction in the number and range of likvelis is predicted in the coming decades. The authors emphasize that the most effective way to guarantee the future of this species is through strengthening the protection of Lomami National Park.
