The grey-cheeked mangabey is one of Uganda’s most charismatic forest primates and one of the few species for which Kibale National Park is internationally recognised as the primary research and viewing site. Large, noisy, and possessed of a distinctive loud gobbling call that carries hundreds of metres through the forest, the grey-cheeked mangabey is impossible to miss when it is present — and in Kibale, it is almost always present, often in the same areas as the park’s famous chimpanzee population.
Physical Description
The grey-cheeked mangabey (Lophocebus albigena) is a large monkey weighing 6 to 11 kilograms. The coat is predominantly dark — brownish-black — with the distinctive grey cheek patches that give the species its name. The head has a prominent crest of longer dark hair. The tail is long and often held in a characteristic upward arc. Large, mobile eyes and prominent brow ridges give the face an expressive, somewhat stern appearance. The species is sexually dimorphic — males are larger and have larger canines — but less dramatically so than baboons or colobus.
The grey-cheeked mangabey’s most recognisable feature is its call: a loud, whooping gobble that begins as a series of sharp barks and builds into a rolling series of lower calls. Adult males produce the call most frequently, and in Kibale it is one of the most reliably heard forest sounds — often the first indicator of mangabey presence before the animals themselves are located in the canopy.
Ecology and Behaviour
Grey-cheeked mangabeys are primarily frugivores, supplementing their diet with seeds, young leaves, insects, and occasionally small vertebrates. They are arboreal, preferring the mid-to-upper canopy of closed-canopy forest, and range widely across large home ranges of 50 to 200 hectares. They live in multi-male, multi-female groups of 5 to 30 individuals, with a dominance hierarchy among both males and females.
In Kibale, grey-cheeked mangabeys frequently associate with other forest primates — red-tailed monkeys, red colobus, and blue monkeys — in mixed-species foraging groups. These associations are thought to improve predator detection and may provide access to food trees that individual species are less efficient at finding independently. The groups are dynamic, with composition changing as individual species’ movements diverge and reconverge during the day.
The Chimpanzee Connection
One of the most dramatic aspects of grey-cheeked mangabey ecology in Kibale is their relationship with chimpanzees. Chimpanzees hunt mangabeys as prey, using coordinated group hunting tactics that can result in multiple captures in a single hunt. Mangabeys have alarm calls specific to chimpanzees and show pronounced avoidance of areas where chimpanzee hunting parties are active. The predator-prey dynamic between two highly intelligent primate species in the same forest is one of the most studied and ecologically complex relationships in African primatology.
Grey-Cheeked Mangabeys in Uganda
Kibale National Park is the primary site for grey-cheeked mangabey viewing in Uganda, with habituated groups that can be observed on forest walks and during the chimpanzee trekking experience. The species is also present in Budongo Forest, Bwindi, and other forest areas in western Uganda. The Kibale population has been the subject of long-term research for decades — some of the most detailed knowledge of mangabey social behaviour and ecology comes from this population. A visit to Kibale that includes time with both chimpanzees and mangabeys — and ideally encounters where both are present simultaneously — is one of the richest primate experiences available anywhere in Africa.
