Ungulates, or hoofed animals, are a particularly important, yet arguably understudied group of herbivorous species in tropical ecosystems. They structure the latter by dispersing seeds, modifying the soil when wallowing in mud areas or when searching for minerals under the floor. Ungulates consist of a variety of species, ranging from the 400kg bongo to the 4kg blue duiker. The intact forests of Nouabalé-Ndoki provide a secure habitat for populations of various ungulate species.
Forest Buffalos
In local languages : Mpakasa, Ngombo (Lingala), Niati (Bendzele), Mboko (Mbangombe)
Because they live in dense vegetation, male forest buffaloes (Syncerus caffer nanus) can rarely measure their strength in head-to-head competition, which is why their horns are lighter and pushed back compared to those of their savanna cousins. They are also distinguished by their beautiful reddish-brown color, with a darker area on the face, and their much smaller size, usually under 120cm in height against up to 170cm for the savannah buffalo.

Because they live in environments not well suited for large carnivores, buffaloes have few predators, and live at a slow pace in small groups of a maximum of 30 individuals, with no need for seasonal movements. It is rare not to come across one, especially at the end of the day, in Wali Baï as well as in Mbeli Baï. Buffaloes have been known to live for up to 26 years.
In local languages : Mbongo
The majestic spiral-horned bongo feeds on low-level fresh greenery and so tends to readily find food in openings in the forest canopy that let in the light necessary for vegetation to flourish on the forest floor. This means that they are frequently found in areas of broken canopy forest, where there are naturally occurring forest clearings, areas of disturbance by elephants or logging.

Despite their resilience, bongos are rare: naturally widespread in moderate numbers, they are also prized for their horns by trophy hunters. Their numbers in and around Nouabalé-Ndoki also plummeted around 1997 after a particularly heavy rainy season caused an increase in Stomoxys flies, whose bites weakened dozens of bongos found dead in a few weeks. Their population is still slowly recovering.
In local languages : Mbuli (Lingala), Mbiliya (Bendzele, Mbangombe)
Mainly active from dusk to dawn, sitatungas can also be observed during the day, especially in Mbeli Bay, where 150 frequent visitors have been identified over the last two decades. Almost sedentary, they have very small home ranges close to swampy areas to which they owe their characteristic features: long legs and splayed hooves allowing them to move skilfully in marshes.

The hornless females are reddish in color and considerably smaller in size than the males. Males have a darker coat than their close cousins the bongos. Their coats may darken and the stripes and spots fade with age. Their horns can be up to 90cm long, although they rarely use them to fight: their nocturnal barking allows them to estimate the age and strength of their neighbors and to avoid unnecessary fights.
In local languages : depending on the species - Mboloko ((blue duiker), Ngandi (Peter’s duiker), Guomu (Bay duiker), Bemba (Yellow-backed duiker)
Duikers are small antelopes, whose weight can vary considerably depending on the species: from 3.5kg for the blue duiker to 80 for the yellow-backed duiker. Their dwarfism is due to an adaptation mechanism to the scarcity of grass on the forest floor, and often feed on fruits and foliage discarded from the canopy by monkeys, birds or bats. It is therefore not uncommon to see duikers below groups of monkeys.

Despite their great ability to hide, duikers are among the most poached and hunted species in northern Congo for their meat, which is consumed throughout the region. The demand for bushmeat from growing urban areas is a major factor in the unsustainable levels of hunting in northern Congo.