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| Colobus congoensis J. Hart, Amboko, Arenson, Horton, Coates, Kapale, Koko, T. Hart, Gilbert, Sargis et Detwiler, 2026 |
Abstract
We describe and name a new species of African monkey, Colobus congoensis sp. nov. (Primates, Cercopithecidae), from the interfluve region of the Lomami and Congo (Lualaba) Rivers in east-central Democratic Republic of Congo (DRC). Colobus congoensis is a rare and cryptic monkey, poorly known even by local communities bordering its range, some of whom use the vernacular name Likweli for the species. Between 2018 and 2022, 114 field observations were made over an estimated range of 1,700 km2. Colobus congoensis is largely restricted to high, closed canopy forest on deep clay pediments and islands of terra firme forest, where it co-occurs with two other colobine species (Piliocolobus parmentieri and Colobus angolensis). Colobus congoensis was most frequently observed in small groups (mean = 6.2 individuals), often in mixed-species associations. Mitochondrial and morphological data confirm the attribution of C. congoensis to the genus Colobus and reveal that it is the sister to Colobus satanas, from which it is geographically separated by more than 1,200 km. Comparative analysis of C. congoensis vocalizations also reveals structural similarities with C. satanas to the exclusion of other Colobus species. Among other features, C. congoensis is distinguished from C. satanas and other Colobus species by its small size, a striking orange cream patch surrounding the mouth, philtrum, and portions of the inferior nasal alae on an otherwise black face, and a white perianal patch that is covered with fine white hairs in males and is glabrous in females. We propose a preliminary IUCN Red List classification of Endangered (EN) for C. congoensis based on its small range area and population size, coupled with the projected impact of increased hunting pressure and habitat conversion. Protection of Lomami National Park, within which most of the C. congoensis range occurs, and engagement of local communities in not hunting the species are the most important actions needed to ensure the conservation of C. congoensis.
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| An illustration of Colobus congoensis, whose common name is the local vernacular name, “likweli.” Illustration: Kimio Honda |
Systematics
Family Cercopithecidae Gray, 1821
Subfamily Colobinae Blyth, 1863
Subtribe Colobina Blyth, 1863
Genus Colobus Illiger, 1811
Colobus congoensis J. Hart, Amboko, Arenson, Horton, Coates, Kapale, Koko, T. Hart, Gilbert, Sargis, and Detwiler, sp. nov.
Etymology: The nominal congoensis refers to the species range limited to the Democratic Republic of Congo. Likweli, the vernacular name given to the species by communities bordering its range, is the recommended common name.
Diagnosis and Description: A small, long-tailed Colobus monkey that exhibits little sexual dimorphism in overall pelage coloration. The pelage of the limbs and torso is black. Hair length is longest on the upper shoulders and back (Color 89 in [54]), producing a sheen in some lighting and a cape-like pelt in some individuals. Body hairs are relatively short (~9–12.5 cm long in the male; ~ 6–8 cm long in females at mid-dorsum). The tail is largely black. Older individuals may show gray hairs (Glaucous Colors 79–80 in [54]) along the caudal dorsum and the tail, as seen in YPM MAM 17308, which also exhibits heavily worn dentition in the associated cranium, indicating an advanced age for this individual (Text A and Fig B in S4 File). The single male examined had a small, black terminal tail tuft in the fresh specimen, not seen on the two females. The head in both sexes is framed by long black hairs (~4–6 cm) on the forehead and sides of the face. The dark glabrous face is marked in both males and females by ...
John A. Hart, Junior D. Amboko, Julia L. Arenson, Emma R. Horton, Kathryn F. Coates, Jean-Pierre I. Kapale, Mardoché B. Koko, Terese B. Hart, Christopher C. Gilbert, Eric J. Sargis and Kate M. Detwiler. 2026. Likweli: A remarkable New Species of Colobus Monkey from the Lomami National Park, Democratic Republic of Congo. PLoS One. 21(7): e0349857. DOI: doi.org/10.1371/journal.pone.0349857 [July 15, 2026]












































