The research was conducted by University of Georgia, University of Maryland, the Wildlife Conservation Society, ICCN (Congolese Wildlife Authority), African Wildlife Foundation, Zoological Society of Milwaukee, World Wildlife Fund, Max Planck Institute, Lukuru Foundation, University of Stirling, Kyoto University, and other groups.

Using data from nest counts and remote sensing imagery, the research team found that the bonobo avoids areas of high human activity and forest fragmentation.

According to the model developed by the researchers in the study, as little as 28 percent of the bonobo's 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. 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," lead author Dr. Jena R. Hickey of Cornell University and the University of Georgia, said.

The bonobo is smaller in size and more slender in build than the common chimpanzee. The great ape's social structure is complex and matriarchal. Unlike the common chimpanzee, bonobos establish social bonds and diffuse tension or aggression with sexual behaviors.

Second author of the study, Dr. Janet Nackoney, said 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. The results point to the need for more places where bonobos can be safe from hunters, which is an enormous challenge in the DRC.

The study is published in journal Biodiversity and Conservation.