The forests of the Democratic Republic of the Congo continue to yield surprises. Scientists have formally described a new species of colobus monkey, Colobus congoensis, known to local Balanga people as Likweli and to the Mituku as kasaba nkoni. The announcement rests on rigorous evidence gathered over years rather than sudden revelation.
A peer-reviewed study published in PLOS ONE on 15 July 2026 sets out the case. The monkey is small, long-tailed and black, with a cape-like mantle across the shoulders, a black face broken by an orange-cream patch around the mouth and philtrum, and a white patch below the tail. It inhabits high closed-canopy forest on deep clay soils and terra firme islands between the Lomami and Lualaba rivers, in an area of roughly 1,700 square kilometres.
Field teams recorded 114 observations between 2018 and 2022. Average group size stood at 6.2 individuals. The species shares its range with two other colobus monkeys, Piliocolobus parmentieri and Colobus angolensis, yet remains distinct in appearance, voice and genetics.
A voice that carries
One of the clearest markers is the roar. Recordings show a rapid pulse rate, high fundamental frequency, frequency modulation and a terminal snort. These calls often betray the monkey's presence in the canopy long before it is seen. The animal is described as cryptic and shy, heard more often than observed.
John A. Hart, lead author of the study, said:
Our team evaluated multiple datasets that all reached the same conclusion: Likweli is a distinct species of Colobus monkey we haven’t seen before.
Hart also credited the contribution of Congolese colleagues.
