Bonobo (Pan paniscus) Conservation Strategy 2012–2022

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•  Sankuru Reserve (23,161 km²), created in 2007

•  the proposed Lomami National Park (9,000 km²), to be surrounded by a buffer zone of 

approximately 16,380 km² with Wildlife Reserve status

During the participatory process for the creation of Lomami National Park, the results of the sur-

veys initiated in 2007 (Hart et al. 2009) were instrumental in proposing boundaries based on known 

locations of animals and people. The 2007 surveys highlighted the biological richness of the zone. 

Several species or subspecies of endemic primates, one new to science (Hart et al. 2012) were 

discovered in the diverse habitats, which include dense tropical rainforest, forest-savanna mosaic, 

flooded areas and large rivers. Despite the remoteness of the area, wildlife, including bonobos, is 

under intense pressure from the commercial bushmeat trade (Hart & Hart 2011).

The number of bonobos in the proposed national park with the surrounding buffer zone (including 

the south-eastern portions of the Sankuru Reserve between the Tshuapa and Lomami Rivers) is 

estimated to be 9,500 individuals (5,800–13,700; ICCN 2010). The bonobos seem to be more con-

centrated in the south, particularly in the Luidjo and Kasuku river basins and in the forests border-

ing the patchwork of savannas in the southern part of the future park. The southwestern boundary 

of the future Lomami National Park is contiguous with the Sankuru Natural Reserve (23,161 km²), 

created in 2007. However, surveys covering just over half of the Sankuru Natural Reserve, west of 

the Tshuapa River, found that bonobos were present in just 17% of the reserve (the Lomela and 

Katako-Kombe territories in the east) and were absent in the south-central and southwest area, 

close to the town of Lodja (Hart et al. 2009; Liengola et al. 2009). With a human population of over 

78,000 inhabitants living in and around the Sankuru Reserve, signs of intense hunting pressure 

were widespread. Over half of the reserve is secondary or degraded forests, fragmented by areas 

of human occupation. 

3.3 Knowledge Gaps and Conclusions

Current knowledge of the status of bonobos is incomplete since recent bonobo surveys cover less 

than 30% of their historical range. While these data indicate that most bonobos reside in PAs (or 

proposed PAs) and buffer areas in the four strongholds, there are suitable conditions for bonobos 

outside protected areas where no recent surveys have been undertaken. These are areas with:

•  low human occupation

•  low deforestation

•  low edge density

•  further distance from human activities (agriculture, roads) 

•  further distance from rivers

•  high forest cover

It is important to note that the predictive model was limited by the data available at the time of 

the 2011 workshop and should be considered as a work in progress to be refined as more data 

become available (Hickey et al. 2012). 

Undertaking surveys of previously unsurveyed areas is paramount to identify possible additional 

sites for protection with a view to a) increasing the proportion of the bonobo population under 

protection and b) maintaining habitat continuity to ensure continued gene flow between bonobo 

populations. Criteria for choosing the sites to be surveyed should be:

1.  areas with the highest predicted value for bonobo occurrence (to be surveyed first)

2.  sites with the largest surface areas

3.  sites adjacent or close to current bonobo priority areas

More than 54% (83,760 km²) of the area predicted to be suitable for bonobos has not been sur-

veyed. To narrow down the areas within the bonobo’s range that should be priorities for future 

survey efforts, the rangewide map of suitable conditions was used to identify priority sites for 

future surveys (see Box 1). This produced a preliminary list of 14 ‘high priority’ areas for future sur-

veys, which are given in order of priority in Table 2 and mapped in Figure 5. The area categorized 

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as high priority is approximately 130,000 km², as experts selected areas that have been surveyed 

in the past where it was judged that a repeat survey should be high priority.

Finally, while it is important to identify areas to be surveyed and potentially new bonobo popula-

tions, the biggest challenge and the most urgent priority for bonobo conservation is to secure their 

effective protection wherever they are known to occur, especially if this is within a protected area.

Box 1. Methods Used to Identify Priority Areas for Future Bonobo Surveys

To determine priorities for future surveys within the bonobo’s geographic range, we used the following three-step approach. 

First, we developed a small programme in Visual Basic that contained a clickable map for recording expert opinions on where 

future survey effort should be located. The base map consisted of a grid with cell size of 0.084 degrees, corresponding to 

approximately 10×10km, with layers for landcover, conservation landscapes, protected areas, rivers and other bodies of water, 

the bonobo’s geographic range and GPS locations of previous survey effort. By default, all cell values were set to no priority (0) 

and any click on a specific cell turned this default value into a priority (1). The programme was available for download via the 

A.P.E.S. Portal and instructions on how to use it were sent to the 35 contributors to the study ‘A spatially-explicit rangewide 

model of suitable conditions for the bonobo (Pan paniscus) for conservation planning’, which has been integral to the process 

of developing the bonobo conservation strategy (Hickey et al. 2012). These experts were asked to provide input on which areas 

should be priorities for future bonobo surveys, together with their justifications for selecting particular cells. Ten respondents 

used the programme to identify priorities, however two combined their input, so a total of nine programme outputs were 

received and analysed.

Data were pooled by summing the number of times each 10 ×10km cell was selected divided by the total number of programme 

outputs received (nine). Results were superimposed on a base layer in ArcGIS, revealing 12 distinct areas that had been 

selected by two or more bonobo experts. Two areas located in the southern extent of the bonobo range were added, because 

the area along the southern range limit was identified as a priority by several experts, but the cells selected were non-overlap-

ping. Thus, a total of 14 areas were classified as high priority for future surveys. These 14 high priority areas were converted 

into polygons and mapped (Fig. 5). The justifications for selection and the summary statistics for each (size, coordinates, mean 

percentage selection) are presented in rank order in Table 2. Cells that were selected only once were classified as priority and 

are shown in Figure 5, but are not listed in Table 2.

Bonobo survey team at work 

near the Ameteka trail in SNP © 

Gay Reinartz/ZSM

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