WCS activities to support the conservation of Grauer’s gorilla date back to 1960 when George Shaller made the first ever maps of the range of this ape in eastern DRC. A follow-up survey was made in the early 1990s to estimate the population size of Grauer’s gorillas. This survey estimated about 17,000 individuals in several separate populations with about 47% of the population residing within Kahuzi Biega National Park. This survey finished just before the civil war in DRC erupted in 1996 and subsequently it has been very difficult to operate in this part of Eastern DRC because of insecurity.
Our work on Grauer’s gorilla focuses on three main areas:
1. Identifying locations of existing populations
WCS has been undertaking surveys of the region since the early 1990s to identify where populations of Grauer’s gorilla occur. This ape is generally found in small populations in remote montane forests and although there is still natural forest between the various populations we do not believe there is much movement between them. As a result it is important to know where the populations occur and then estimate how many gorillas are found in each population. Our surveys in Itombwe Massif have identified some new populations of this ape to the south of where George Shaller recorded them thereby expanding the overall range for this animal.
2. Monitoring of population numbers
We have been undertaking surveys in Kahuzi Biega National Park to estimate the impact of the civil war in DRC on this ape. While it has been difficult to access the same areas that were surveyed in the early 1990s we have been able to survey much of the lowland and highland sectors of Kahuzi Biega National Park since 2000. The results to indicate that Grauer’s gorilla numbers are about 20% of what they were in the early 1990s. To be certain of these results we want to survey the same areas as those surveyed in the past because it is possible these areas contained more gorillas. Security is increasing to the point where this may be possible in the near future but our results to date certainly indicate a major decline in the species population size in this park.
3. Protection of Grauer’s gorilla habitat
Most of our efforts for this species concern the protection of the remaining habitat for this ape. We are supporting ICCN in its management of Kahuzi Biega National park, in particular supporting the re-establishment of a patrol post on the western side of the park to improve law enforcement in the lowland sector. We are also working with other partners to conserve the Itombwe Reserve by zoning the reserve with local communities to finalize the gazettment of this reserve. We are looking for funds to survey the area west of Kahuzi Biega Park where the proposed Punia Community reserve would be established and which contained about 8,000 gorillas in past surveys.
In 2011 WCS participated in the development of a species action plan that was developed for both the Grauer’s gorilla and the eastern chimpanzee in the Maiko-Itombwe Landscape. A process led by the Jane Goodall Institute, this plan identified critical objectives that need to be addressed to save both of these species in this region, particularly the need for land use planning as development interests start to move into the region.