Scientists have recently determined the bonobo population living in one of the largest untouched tropical forests, which is considered a crucial habitat for this endangered species. The research estimates that Salonga National Park in the Democratic Republic of the Congo (DRC) is home to between 8,000 and 18,000 adult bonobos. While the population has remained stable since 2000, there are indicators of a possible decline.
Scientists have recently determined the bonobo population residing in one of the largest untouched tropical forests, often viewed as a vital habitat for this endangered species. Over two decades, a team of 48 researchers conducted studies estimating that Salonga National Park in the DRC hosts between 8,000 and 18,000 adult bonobos. Although the population appears stable since 2000, there are troubling signs that it may be in decline. The study spearheaded by researchers from the Max Planck Institute of Animal Behavior (MPI-AB) also identifies factors that positively influence bonobo populations, offering practical conservation strategies for these primates.
“Estimating the bonobo population in Congo’s largest protected area is a major advancement in conservation efforts,” notes Mattia Bessone, the lead author of the study. “Our findings underscore the critical role of park rangers in safeguarding this endangered species, suggesting that Salonga’s success could be a model for future conservation initiatives.”
Africa’s largest untouched forest
Salonga National Park in the Democratic Republic of the Congo stands as Africa’s largest protected forest park, covering an area comparable to Switzerland. This pristine, primary forest is recognized as a safe haven for the greatest population of bonobos, a great ape species found exclusively in the Congo. In Salonga, bonobos have some protection against the commercial hunting and deforestation that threaten their survival in other areas. However, despite Salonga’s reputation as the bonobo stronghold, the precise number of bonobos residing there was previously unknown due to the lack of a comprehensive study across its 33,000 km² protected area and a 9,000 km² corridor of human settlements.
“Previously, there was an outdated estimate regarding the bonobo population in Salonga,” explains Barbara Fruth, who oversaw the IUCN red list evaluation of the species in 2016, “but it was merely an assumption based on surveys covering less than twenty percent of the park.”
Recognizing the importance of Salonga, Fruth and other scientists saw the park as key to gathering essential data for bonobo conservation.
“What makes Salonga unique is that it is the only location where repeated surveys have been conducted in the same areas,” says Fruth, a group leader at MPI-AB. “In such a vast country, only Salonga allows us to track trends and evaluate whether bonobo populations are declining in Congo.”
Two decades of data compilation
Mattia Bessone, a postdoctoral researcher under Fruth’s guidance, spearheaded the project to compile all surveys from Salonga between 2000 and 2018, totaling 13 surveys conducted by 48 scientists. Bessone faced hurdles due to the different methods employed to estimate the bonobo population, ranging from traditional nest counting to advanced motion-triggered cameras. He utilized statistical methods to harmonize these variations and generate population estimates for bonobos throughout Salonga, including previously unstudied regions. This effort is the most extensive temporal comparison of a bonobo population conducted so far, highlighting its broad geographical relevance.
The findings provide several crucial insights that could enhance conservation strategies and management efforts for bonobos.
What bonobos require to thrive
The research estimates the population of adult bonobos in Salonga to be between 8,000 and 18,000, a figure that “isn’t surprising,” according to Bessone, as it aligns with earlier projections based on smaller surveys. The population appears to have remained steady since 2000, yet scientists noticed a worrying downward trend in both density and distribution, though this change isn’t statistically significant.
“This indicates that bonobos are not in immediate peril, but we must remain alert and continue investing in conservation initiatives to ensure their survival,” says Bessone.
The study draws attention to specific factors that could guide future conservation efforts.
The presence of primary forest is a key indicator for where bonobos are likely to occur, as living near villages tends to have a detrimental impact on their numbers. Interestingly, not all human activity negatively affects bonobos; they tend to be found more frequently near park ranger stations, indicating the protective influence of law enforcement.
“We still cannot pinpoint what actions by the rangers contribute to this positive effect,” remarks Bessone. “It’s possible that rangers deter poachers. Whatever the cause, it is evident that the presence of enforcement positively impacts bonobos.”
A positive observation arose on the park’s southern side, where villages of a traditional minority have existed since before Salonga National Park was established in 1970. “In these communities, a cultural taboo exists that prohibits hunting bonobos,” states Bessone. “This might be what enhances their bonobo population.”
By monitoring one of Africa’s most pristine locations over a long period, the implications of this study are important.
“The primary threats to bonobos are deforestation and commercial hunting, and our results indicate that conserving forests and strengthening law enforcement yield tangible benefits for bonobo preservation,” Fruth emphasizes. “We hope this encourages national and international conservation entities to increase investment in Salonga and other protected areas, ensuring that bonobos continue to thrive in our world for generations to come.”
