Small Monkeys

Easily observed in the trees above the research camps or above the Park's headquarters in Bomassa, the Old World monkeys found in Nouabalé-Ndoki National Park are a large family of monkeys remarkable for their diversity of colors and appearances. Their size also varies greatly, ranging from 40 to 70cm for some species, yet they all belong to the same family of primates, cousins of the great apes, and therefore of humans. Although not considered endangered, these species are found in every bushmeat market in the region, and their survival could quickly be threatened.
In local languages : Mossila
Named after the Italian naturalist and explorer Jacques Savorgnan de Brazza, the De Brazza Monkey (Cercopithecus neglectus) is known for its ability to be quiet, slow and observant. Its stunning appearance includes a thick red eyebrow, a long white beard, an equally white hindquarters and a blue scrotum in males. The rest of its body, in shades of gray, allows it to blend in with the bark of the trees.
De Brazzas’ predators include eagles, leopards and chimpanzees, as well as humans. Found in Central and Eastern Africa, they have become rare in Kenya, Ethiopia and Uganda, where agrarian pressure has reduced their habitat. They are listed as least concern by the IUCN Red List, but more data are needed to establish action plans for their conservation.
In local languages : Kalu
Colobus guereza, known as mantled guereza or black-and-white colobus, is also satirically called "magistrate" because of its long white hairs on its sides, evoking the attire worn in the Congolese judicial system. They sometimes venture onto the ground, especially in the Mbeli baï, or even in the Bomassa base, in search of food.

Guereza are known for their ability to adapt to degraded environments. They are less fussy than their cousins the red colobus, and are satisfied with smaller territories. They are, therefore, more widespread and common throughout northern Congo. Guereza are also known for their group displays of strength, through loud and low coraking and branch-shaking.
In local languages : Kweti (Lingala), Mbeti (Bendzele), Moutenge (Mbangombe)
Moustached monkeys (Cercopithecus cephus) inhabit lowland tropical forests of central Africa. Their appearance varies throughout the Congo Basin, with the common features of a grizzled brownish back and crown. The ones that inhabit Nouabalé-Ndoki owe their name to the bar of vivid white hair that separates their mouth from their bright blue face, flanked by yellow sideburns.

These colorful monkeys, with a red tail the size of their bodies, feed mainly on abundant fruiting trees or forage thoroughly for scattered fruits and insects. They are characterized by their rapid and abrupt movements, as well as their sharp and short chirping alarm calls. They are also characterized by forming polyspecific associations with other monkeys, which improve foraging efficiency and anti-predatory strategies.
In local languages : Koi
More elusive than the above species, the putty-nose monkeys (Cercopithecus nictitans), has a distinctive white patch on its nose which contrasts sharply with its black face. Mostly dark, its hair is colored in an elegant gradient towards an almost golden shade of beige. Putty-nose monkeys live high in the canopy in groups of 12 to 30 individuals dominated by a male.

Studies have proven that putty-nose monkeys have a complex vocalization system with specific sounds depending on the threat they face and combinations to make sentence-like messages. A specific alarm call has been recorded for the first time in Nouabalé-Ndoki and has allowed a deeper understanding of their vocalizations, while raising new questions.

Due to heavy hunting pressure and habitat loss, this species has been listed as Near Threatened by the IUCN.
In local languages : Ngada
Gray-cheeked mangabeys (Lophocebus albigena) are large, long tailed monkeys with dark fur on their bodies and gray tufts of hair around their faces, which give them a punk look. However its naked face, framed by long black eyebrows and fine paler hair on its cheeks gives it grace and poise.

They utter distinctive loud low-pitched “whoop-gobble” calls through specialized air sacs; these calls are specific to a group and used to communicate with neighboring groups to advertise their presence and avoid conflicts.
In addition to play a role as seed dispersers, gray-cheeked mangabeys are also thought to act as pollinators as they spend time among flowers in the upper canopy and occasionally feed on them. This species is listed as Vulnerable.