Meet the Orange-Lipped 'Likweli' Monkey, a New Species That Was Discovered in the Congo Rainforest

Researchers have identified a new species of monkey living in the rainforests of the Democratic Republic of the Congo, a discovery that adds a rare entry to the short list of African primates catalogued in modern times. Local communities call the animal the "Likweli," and a team of scientists formally described it in a study published July 15 in the journal PLOS One. According to the researchers, it is only the fifth new monkey species identified on the African continent in three-quarters of a century, underscoring how unusual the find is.

The Likweli stands out visually. It is covered in bristly, dark fur, its muzzle is ringed with a pale orange-to-cream coloring, and it carries a pale patch near its tail. Adults tip the scales at roughly 15 pounds, putting them in the same weight class as a small household dog, and measure close to four feet when their body and tail are counted together. Field observers have also noted the animal's distinctive vocalization, a deep, guttural call that has been likened to a snorting pig or a croaking frog rather than typical monkey chatter.

The path to confirming the species took nearly two decades. Conservationists working along the Lomami River — a waterway that cuts through the heart of the DRC before joining the larger Congo River — captured a partial photograph of an odd-looking monkey back in 2008. Although the image only captured a portion of the animal's body, it was enough to convince the field team that they had encountered something outside the known catalogue of Congo Basin primates.

From that initial sighting, researchers spent years gathering additional evidence before they were confident enough to formally classify the Likweli as its own species. That kind of extended timeline is common in primate taxonomy, where distinguishing a genuinely new species from a regional variant of an already-documented one requires physical specimens, genetic testing, and repeated field observations, not just a single photograph or sighting.

The discovery carries weight beyond scientific classification. New mammal species, particularly primates, are increasingly rare finds anywhere in the world, and each one offers researchers fresh insight into the biodiversity still hidden within the Congo Basin's dense forest cover, one of the largest and least-studied tropical ecosystems on Earth. The region has long been recognized as a reservoir of undiscovered species, but political instability, logging, and limited research funding have historically slowed formal scientific surveys there.

That backdrop also fuels concern about the Likweli's future. Scientists involved in the study believe the newly described monkey is likely already at risk, even though it has only just been given a name. Habitat loss driven by logging and land conversion across the DRC's forests threatens many species before researchers have a chance to fully document their populations or range, and conservationists warn the Likweli could face pressure similar to that confronting other Congo Basin primates.

Researchers say further fieldwork will be needed to determine how many Likweli monkeys exist and how widely they are distributed across the Lomami River region and surrounding forest. Establishing a clearer population estimate is expected to be a key step toward deciding whether the species warrants formal protective status, a process that typically follows the identification of any newly described mammal believed to be vulnerable.

Source: Smithsonian Magazine