Human Expansion Squeezing Out Bonobo Populations In The Congo
November 27, 2013

Human Expansion Squeezing Out Bonobo Populations In The Congo

April Flowers for - Your Universe Online

The bonobo, formerly known as the pygmy chimpanzee, is quickly losing space in a world with growing human populations, according to the most detailed range-wide assessment ever conducted.

The study, published in Biodiversity and Conservation, reveals that the loss of usable habitat is attributed to both forest fragmentation and poaching.

The international team included researchers from University of Georgia, University of Maryland, the Wildlife Conservation Society (WCS), ICCN (Congolese Wildlife Authority), African Wildlife Foundation, Zoological Society of Milwaukee, World Wildlife Fund (WWF), Max Planck Institute, Lukuru Foundation, University of Stirling, Kyoto University, and other groups.

The team analyzed data from nest counts and remote sensing imagery, finding that the bonobo -- one of humankind's closest relatives -- avoids areas of high human activity and forest fragmentation. The model developed by the team reveals that as little as 29 percent of the bonobo's historical range remains suitable.

"This assessment is a major step towards addressing the substantial information gap regarding the conservation status of bonobos across their entire range," said Dr. Jena R. Hickey of Cornell University and the University of Georgia. "The results of the study demonstrate that human activities reduce the amount of effective bonobo habitat and will help us identify where to propose future protected areas for this great ape."

"For bonobos to survive over the next 100 years or longer, it is extremely important that we understand the extent of their range, their distribution, and drivers of that distribution so that conservation actions can be targeted in the most effective way and achieve the desired results," said Ashley Vosper of the Wildlife Conservation Society. "Bonobos are probably the least understood great ape in Africa, so this paper is pivotal in increasing our knowledge and understanding of this beautiful and charismatic animal."

"By examining all available data provided by a team of leading researchers, we can create the kind of broad-scale perspective needed to formulate effective conservation plans and activities for the next decade," said Dr. Hjalmar S. Kühl of the Max Planck Institute for Evolutionary Anthropology.

Compared to the common chimpanzee, the bonobo is smaller in size and has a more slender build. This poorly known and endangered great ape has a complex matriarchal social structure, and unlike the chimpanzee, they use sexual behaviors to establish those social bonds and diffuse tension.

The bonobo's entire range lies within the Democratic Republic of Congo, which is the largest country in sub-Saharan Africa and is currently beset with warfare and insecurity.

A predictive model was developed by the team using available field data to define bonobo habitat. The model was then interpolated to areas lacking data. Numerous organizations collected bonobo nest locations between 2003 and 2010, which the team compiled to produce 2,364 "nest blocks." A nest block is defined as a 1-hectare area occupied by at least one bonobo nest.

A number of factors that address both ecological conditions (such as forests, soils, climate, and hydrology) and human impacts (distance from roads, agriculture, forest loss, and density of "forest edge") were tested, producing a spatial model that identified and mapped the most important environmental factors contributing to bonobo occurrence. The most important predictor of bonobo presence is distance from agricultural areas, according to the researchers. They also discovered that only 27.5 percent of the suitable habitat is located in areas that are currently protected.

"Bonobos that live in closer proximity to human activity and to points of human access are more vulnerable to poaching, one of their main threats," said Dr. Janet Nackoney, a Research Assistant Professor at the University of Maryland. "Our results point to the need for more places where bonobos can be safe from hunters, which is an enormous challenge in the DRC."

Dr. Nate Nibbelink, Associate Professor at the University of Georgia, added, "The bonobo habitat suitability map resulting from this work allows us to identify areas that are likely to support bonobos but have not yet been surveyed, thereby optimizing future efforts."

"The fact that only a quarter of the bonobo range that is currently suitable for bonobos is located within protected areas is a finding that decision-makers can use to improve management of existing protected areas, and expand the country's parks and reserves in order to save vital habitat for this great ape," said Innocent Liengola, WCS's Project Director for the Bonobo Conservation Project and co-author on the study.

"The future of the bonobo will depend on the close collaboration of many partners working towards the conservation of this iconic ape," said Dr. Liz Williamson of the IUCN/SSC Primate Specialist Group and coordinator of the action planning process which instigated the bonobo data compilation for this study.