Science

The Djéké Triangle, where Mondika is located, is a 100 square kilometer area of undisturbed, intact forest, which has attracted the attention of researchers since the early 1990s because of the unusually high density of western lowland gorillas. The Triangle holds around 8 gorillas per kilometer, almost 4 times the average density of the region.

There has been a camp at Mondika since 1995, from which researchers and trackers have habituated three groups of western lowland gorillas to human presence. Habituation allows researchers to observe primate behaviors on a daily basis without interference, and thus to better understand their ecology and social structure, and to collect long-term data. Mondika is one of only five successful habituation sites in the whole of the western gorilla geographic range in Central Africa.

When this site was created, almost 30 years ago, virtually nothing was known about the western lowland gorillas. The ongoing efforts of dedicated researchers have led to groundbreaking discoveries about one of man’s closest cousins. Since 2023, the Djéké Triangle is now part of the Park.

Stuck between the swamps of two rivers, Goualougo is a particularly difficult part of the forest to access, so much so that when scientists first arrived in this area they met “naive” chimpanzees, who reacted to humans with curiosity rather than fleeing, suggesting that they had never seen humans before. Since 1999, research work at Goualougo has focused on the social structure and behavior of chimpanzees, including their vast repertoire of tool use.

The study of chimps in Goualougo has revealed tool-using behaviors not previously documented elsewhere in Africa. The Goualougo triangle became part of the Park in 2012, and research work in this zone has allowed significant advancement in the understanding of the long-term impact of logging on chimpanzees.

With the habituation of a group of gorillas residing within the Moto chimpanzee community’s territory, Goualougo has also become the only research site with both chimp and gorillas habituated to human presence. This has led to groundbreaking discoveries about social interactions between different species of great apes.

At 13 ha, Mbeli Baï is the largest swampy forest clearing in the southern part of the Park. With mineral-rich soil and floating plants, the bai is a safe place to forage, which also provides unique opportunities for social interaction for many species such as gorillas, elephants, and sitatungas. At the edge of the clearing, a 9 m high observation platform has enabled researchers to study these focal species since 1994. Long-term data regarding population dynamics and demography gathered at the baï is crucial to assess the population’s vulnerability to threats, predictions of their ability to recover from decline, and formulation of effective conservation strategies. Due to the long lifespan of gorillas and elephants, this can only be done through a permanent research presence and requires a long-term investment. The Mbeli Baï Study is the longest continuous study on western lowland gorillas and second longest study on forest elephants. Since its creation, 547 western lowland gorillas, 662 forest elephants, as well as 150 sitatungas, and 57 forest buffaloes have been identified and are individually known.

After the discovery of low-frequency rumbling and infrasonic communication among elephants in the late 1980s, a new idea emerged: studying forest elephants even where you can’t see them. Based on this idea, the Elephant Listening Project (ELP) was born in 1999 at the K. Lisa Yang Center for Conservation Bioacoustics at Cornell University with the mission to support conservation efforts by eavesdropping on forest elephants and poachers by placing Autonomous Recording Units (ARUs) deep in the rainforest.

Since 2017, the ELP has worked in Nouabalé-Ndoki National Park. By listening to the sounds of the rainforest, the project gathers important information on forest elephant population trends and landscape use, when and where illegal gun hunting takes places as well as how logging and poaching influences elephant behavior.