Density estimation of bonobos (Pan paniscus) in Salonga National Park, Congo

In December 1997 and January 1998 a survey was conducted to investigate the presence of bonobos (Pan paniscus) in the northern sector of Salonga National Park in the Democratic Republic of Congo. The park is the largest African rainforest reserve, and was created in 1970 to protect endemic species such as the bonobo. Until now, however, no one has verified whether bonobos live in the park in viable numbers. Bonobo nests were therefore counted at three sites on the rivers Yenge and Salonga, along a total of 7.5 km line transects. Bonobo density in this area was found to be 1.15 animals per square km, lower than densities found in the Lomako Forest and Wamba, between 200 and 300 km north of the park, but higher than those found in Yalosidi and Lilungu, ca. 100 km east and 150 km north-east of the park, respectively. However, hunting pressure was significant in the park, and the ongoing war does not improve the situation. The Salonga National Park is the only area in bonobo territory that is at least theoretically protected by law. Active conservation programs to protect bonobos should be undertaken as soon as the situation in the country permits.