For the first time, a detailed, range-wide habitat assessment of the bonobo, a great ape native to the Democratic Republic of the Congo (DRC), has found that the already endangered species is under immediate threat of losing forest space due to human activity and growing human populations. University of Maryland Department of Geographical Sciences professor Janet Nackoney is one of the authors from international universities and institutions that were part of this critical study, which appears in the December edition of Biodiversity and Conservation.
The study revealed that the bonobo is threatened by a combination of habitat fragmentation and human activities that put pressure on existing habitat and contribute to increased poaching.
The bonobo is smaller in size and more slender in build than the common chimpanzee. Its social structure is complex and matriarchal. Unlike the common chimpanzee, bonobos establish social bonds and diffuse tension or aggression with sexual behaviors. A stable, sustainable habitat is critical for the species' survival. Using data from nest counts and remote sensing imagery, the research team found that the bonobo—one of humankind's closest living relatives—avoids areas of high human activity and forest fragmentation, and about 28 percent of its range is characterized as suitable for habitation.
"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," Dr. Nackoney said. "This research increases our understanding of threats to bonobos and their distribution, and we hope it will help prioritize conservation interventions. Overall, the results show enormous challenges for future bonobo conservation efforts in a country with persistent poverty and growing human populations that depend heavily on resources from surrounding ecosystems. Maps and models such as those produced by this study are essential tools for protected area planning and for targeting locations of future conservation activities."
Dr. Nackoney's research focuses on developing spatial models and using remote sensing technology for assisting biodiversity conservation efforts in Africa. UMD was recently ranked fourth globally for its leadership in remote sensing research and technology by the journal Scientometrics.
The entire range of the bonobo lies within the lowland forests of the DRC, the largest country in sub-Saharan Africa and currently beset with warfare and insecurity. The research team created a predictive model using available field data to define bonobo habitat and then interpolated to areas lacking data. Specifically, the team used data on bonobo nest locations collected by numerous organizations between the years 2003-2010. The team compiled data from 2,364 "nest blocks," with a block defined as a one-hectare area occupied by at least one bonobo nest.
The team then tested a number of factors that addressed both ecological conditions (describing forests, soils, climate, and hydrology) and human impacts (distance from roads, agriculture, forest loss, and density of "forest edge") and produced a spatial model that identified and mapped the most important environmental factors contributing to bonobo occurrence. The researchers found that distance from agricultural areas was the most important predictor of bonobo presence. In addition to discovering that only 28 percent of the bonobo range is classified as suitable for the great ape, the researchers also found that only 27.5 percent of that suitable bonobo habitat is located in existing protected areas.
This collaborative effort was initiated at a bonobo conservation action planning meeting held in Kinshasa, DRC in January 2011.
"Our research would not have been possible without contributions from the numerous bonobo scientists who came together to provide key data on locations of bonobo observations. Although compiling and standardizing the data was challenging, it was a rewarding experience to help facilitate this collaboration in order to develop a map and consensus about threats to suitable bonobo habitat," Dr. Nackoney said.
December 4, 2013