Say the word “endangered primate” and most people picture a Mountain Gorilla — those vast, gentle giants whose recovery story has become one of conservation’s most celebrated chapters. Or perhaps a chimpanzee, or an orangutan. Animals with faces that have appeared on magazine covers, in documentaries, in fundraising campaigns that have reached millions of people around the world.

Nobody pictures the Drill.

And that invisibility — that profound, almost total absence from the public conversation about wildlife — is precisely why the Drill (Mandrillus leucophaeus) is in the trouble it is in today. It is one of the most endangered primates in all of Africa. It is rarer than the gorilla. It is more threatened than the common chimpanzee. And the vast majority of people who care deeply about wildlife conservation have never heard its name.

This is its story — and it is one that cannot afford to go untold any longer.

What Is the Drill?

The Drill is a large, powerfully built Old World monkey found in a narrow strip of rainforest spanning southeastern Nigeria, southwestern Cameroon, and the island of Bioko off the coast of Equatorial Guinea. It is closely related to the Mandrill — that spectacularly coloured primate whose vivid red and blue facial markings have made it one of Africa’s most recognisable animals.

The Drill shares the Mandrill’s imposing build and social complexity, but where the Mandrill is flamboyant, the Drill is restrained. The male’s face is framed in jet black skin, with a striking crimson lower lip and chin that flushes more intensely during moments of excitement or dominance display. The rump, visible when the animal moves through the forest, is a vivid patch of pink, purple, and red — a signal of status and health used in social communication.

Adult males are formidable animals, weighing up to 50 kilograms and moving through the forest with the quiet authority of an animal that has few natural predators. Females are considerably smaller, typically weighing around 12 kilograms, and form the stable social core around which Drill society is organised.

A Society Built on Complexity

Drills live in multi-level societies of extraordinary sophistication — a social structure that researchers have only begun to fully understand in recent decades.

At the base level, females and their offspring form small, stable core units of 2 to 5 individuals. These core units associate with one another to form harem groups of 15 to 30 animals, each led by a dominant male who maintains exclusive breeding access through a combination of physical presence and social signalling. Multiple harem groups then come together periodically to form supergroups of up to 200 individuals — one of the largest aggregations of any primate species on earth.

These supergroups are not random gatherings. They appear to be coordinated events, triggered by the availability of large food sources such as fruiting trees, and maintained through a complex system of vocalisations that researchers are still working to decode. Within the supergroup, individual animals recognise one another, maintain established relationships, and navigate a social hierarchy of remarkable nuance.

This level of social complexity is typically associated with primates far more studied than the Drill — chimpanzees, bonobos, baboons. The fact that it exists in an animal so little known to science is a reminder of how much we still do not understand about the natural world.

The Threat That Is Erasing Them

The Drill’s range has always been limited. Unlike the gorilla or the chimpanzee, which historically occupied vast swathes of the African continent, the Drill was always confined to a relatively small geographic area. This makes it inherently vulnerable — a species with nowhere else to go when its habitat comes under pressure.

And the pressure has been relentless.

Bushmeat hunting is the single greatest threat to the Drill’s survival. In Nigeria and Cameroon, Drill meat is considered a delicacy and commands high prices in urban markets. Drills are hunted with guns, snares, and dogs, often in organised commercial operations that target entire groups at once. Because Drills live in large, cohesive social groups and do not scatter easily when threatened, a single hunting event can eliminate dozens of animals simultaneously — a catastrophic loss for a species with slow reproductive rates.

Habitat destruction compounds the crisis. The Cross River region of Nigeria and the forests of southwestern Cameroon — the heart of Drill territory — are among the most heavily deforested areas in West and Central Africa. Agricultural expansion, logging, and charcoal production have reduced and fragmented the forest to a fraction of its historical extent, isolating Drill populations and preventing the genetic exchange that healthy wildlife populations depend on.

The island of Bioko, which hosts a genetically distinct Drill population, faces its own acute crisis. Despite being part of Equatorial Guinea — a relatively wealthy nation by regional standards — Bioko’s wildlife has been devastated by hunting, with Drill populations declining by an estimated 50% in the past three decades.

The Numbers Behind the Crisis

The Drill is listed as Endangered on the IUCN Red List, with a population estimated at fewer than 3,000 individuals remaining in the wild. Some researchers believe the true number may be significantly lower, as Drills are notoriously difficult to survey in dense forest and many populations have not been assessed in years.

For context: there are currently more Mountain Gorillas alive in the wild — a species that was once considered functionally extinct — than there are Drills. The gorilla’s recovery has been achieved through decades of intensive, well-funded conservation effort. The Drill has received a fraction of that attention and a fraction of that funding.

The disparity is not a reflection of the Drill’s ecological importance or its conservation value. It is a reflection of its invisibility — the simple, brutal fact that animals people do not know about do not generate the donations, the political will, or the public pressure needed to save them.

The People Fighting to Save It

The situation is not without hope. A small number of dedicated organisations are working to protect the Drill against extraordinary odds.

The Drill Ranch in Calabar, Nigeria — operated by Pandrillus Foundation — is one of the world’s most important Drill conservation facilities, combining a captive breeding programme with community education, anti-poaching initiatives, and forest rehabilitation. Since its founding in the 1980s, the Drill Ranch has bred hundreds of Drills and successfully reintroduced animals into protected forest areas — a painstaking, expensive, and deeply committed effort that has kept the species from the brink.

In Cameroon, the Limbe Wildlife Centre provides sanctuary for orphaned and confiscated Drills, many of them infants whose mothers were killed by hunters. These animals cannot be released into the wild, but they serve as powerful ambassadors — living proof of what is being lost, and what is worth fighting for.

Community engagement is increasingly recognised as essential to long-term Drill survival. Conservation programmes that provide alternative livelihoods to communities that have historically depended on bushmeat hunting — through ecotourism, sustainable agriculture, and ranger employment — have shown promising results in reducing hunting pressure in key areas.

Why the Drill Matters

The Drill is not simply a primate in trouble. It is a keystone species in the forests it inhabits — a large-bodied frugivore whose movement through the forest drives seed dispersal, shapes vegetation structure, and supports the ecological processes that the entire forest depends on. Lose the Drill, and you do not simply lose one species. You begin to unravel the web of relationships that holds the forest together.

There is also something that resists purely ecological framing — something about the Drill’s social complexity, its vivid markings, its quiet intelligence — that speaks to a value beyond the utilitarian. This is an animal with a rich inner life, with relationships and hierarchies and communication systems we are only beginning to understand. It deserves to exist not because of what it does for the ecosystem, but because it is extraordinary in its own right.

Final Thoughts

The Drill will not make headlines. It will not trend on social media. It will not appear in a blockbuster wildlife documentary unless someone decides, deliberately and urgently, to put it there.

But it is here. In the forests of Nigeria and Cameroon and Bioko, in groups that are smaller every year, in a range that is shrinking every decade. It is here, and it is watching the forest disappear around it with the same quiet intensity it has always brought to the world.

The gorilla was saved because people decided it was worth saving. The Drill deserves the same decision.

The only question is whether we make it in time.

Want to go deeper? Read our related posts on the Mountain Gorilla, the Mandrill, and 10 Most Endangered Primates in the World — each one a story of survival at the edge.