Eastern gorilla (Gorilla beringei) Matchie, 1903
Mountain Gorilla (Gorilla beringei beringei) (Matschie, 1903)
Red List: Critically Endangered Distribution: Two distinct populations, one in the Virunga Volcanoes Conservation Area shared by DRC, Rwanda and Uganda, and one mostly in Bwindi Impenetrable National Park, Uganda but ranging into the contiguous Sarambwe Go- rilla Special Reserve in the DRC. CITES: Appendix I since 1975 CMS: Annex 1 since 2005 Population: The Virunga population was estimated to be 400– 500 in the 1950s, fell to 250 by 1981, but successful conservation measures led to its recovery. Despite the turbulent history of the region over the past 20 years, in late 2003 the first census since 1989 revealed that the population in the Virunga mountains had grown by 17 percent to 380. The population in Virunga National Park, DRC, was reported to have increased by 12.5 percent from 72 to 81 gorillas between August 2007 and January 2009 (ICCN, 2009). The population in 2009 was thought to be about 420; a full census is being organized in 2010. The Bwindi popula- tion was not accurately surveyed until the early 1990s when it was found to number between 290 and 310 (Butynski, 2001). In 2002 a census suggested a 7 per cent increase to 320 (McNeilage et al., 2007) but new methods of genetic analysis of samples collected during the 2006 census indicate a population of 300 (Robbins and Williamson, 2008).
Note: The Bwindi population was proposed as a distinct sub-species (Sarmiento et al., 1996) but this has been contested (Stanford, 2001) and is not supported by genetic studies (Garner and Ryder, 1996).
Eastern Lowland Gorilla (Gorilla beringei graueri) (Matschie, 1914; Groves, 1970 – )
Red List: Endangered Distribution: Endemic to eastern DRC. CITES: Appendix I since 1975 CMS: Annex 1 since 2005 Population: In the mid-1990s, the population of Eastern Low- land Gorillas was estimated to be about 17,000 (plus or mi- nus 8,000) with 86 per cent living in Kahuzi-Biega National Park (KBNP) and the adjacent Kasese Forest (Hall et al., 1998). Since then, a decade of civil war, refugee crises and Bushmeat hunting – especially to provision unregulated coltan and cas- siterite mines (Redmond, 2001) – is thought to have caused a significant decline. Insecurity in the region has prevented ac- curate surveys, but the surviving population is thought likely to be below 5,000. Despite the insecurity, surveys by Congolese conservationists and WCS on the Itombwe massif revealed two hitherto undocumented sub-populations of gorillas but also a dramatic decrease in populations compared to 1996 surveys (Plumptre et al., 2009). Recent surveys of the Walikale Com- munity Gorilla Reserve indicate at least 750 gorillas in 80 groups in the forests between KBNP and Maiko National Park/ Tayna Gorilla Reserve.