Scientists Discover a New Monkey With Orange Lips and a Froglike Roar in Congo's Rainforest

Deep in a remote, thickly forested corner of the Democratic Republic of Congo, scientists have identified a previously unknown species of monkey — a mostly black primate marked by striking orange face patches and an unexpectedly deep, froglike roar.

Named Colobus congoensis and known to local communities as the 'Likweli,' the animal is only the fifth new monkey species to be described in Africa in the last 75 years, a rarity that underscores how much remains hidden in the continent's shrinking wild places. Genetic, anatomical and acoustic analyses confirmed that the monkey represents a distinct evolutionary lineage, one that diverged from the black colobus, Colobus satanas.

The discovery was a slow, patient piece of detective work. It began in 2008, when researchers captured a single, partially obscured photograph of an unfamiliar monkey and could not be sure what they were looking at. Roughly a decade later, scientists encountered the animal again and obtained a much clearer image, setting off the years of analysis needed to establish it as a species new to science.

The Likweli is the second new primate to emerge in the past 15 years from the region around the Lomami River, a biologically rich and understudied stretch of Congo's central basin. That the same remote landscape keeps yielding major discoveries suggests scientists have only begun to catalog what lives there — and how quickly some of it could vanish.

Researchers are already recommending that Colobus congoensis be classified as endangered. As an endemic species confined to a small geographic range, estimated at only about 1,700 square kilometers, the monkey is inherently vulnerable to hunting and habitat loss, pressures that are intensifying across the Congo Basin as logging, agriculture and the bushmeat trade push deeper into once-inaccessible forest.

For conservationists, the find is a double-edged discovery: a thrilling reminder that large, charismatic mammals are still out there waiting to be named, and a warning that some may be identified only just in time to document their decline. Protecting the Likweli, scientists say, will require safeguarding the specific patch of Congolese rainforest it calls home — a tall order in one of the most biodiverse and least protected regions on Earth.