The population of critically endangered mountain gorillas living in Africa’s Virunga Massif has grown by 26.3% to approximately 480 individuals in the past seven years according to the newly released results of the 2010 mountain gorilla census.
The last mountain gorilla census of the Virunga region in 2003 estimated a total of 380 animals. The Virunga Massif encompasses national parks in Rwanda, Uganda, and the Democratic Republic of Congo (DRC). Some 302 additional mountain gorillas live in Uganda’s Bwindi Impenetrable National Park, which was not included in this year’s census.
The Virunga Massif mountain gorilla census was conducted by the protected area authorities in three countries: L’Institut Congolais pour la Conservation de la Nature, the Rwanda Development Board, and the Uganda Wildlife Authority.
The census was supported by the International Gorilla Conservation Programme (a coalition of the African Wildlife Foundation, World Wide Fund for Nature, and Fauna & Flora International), the Max Planck Institute for Evolutionary Anthropology, the Dian Fossey Gorilla Fund International, and the Mountain Gorilla Veterinary Project. The census was funded by WWF-Sweden, Fair Play Foundation, and the Netherlands Directorate General for International Cooperation (DGIS) through the Greater Virunga Transboundary Collaboration.
During the census, six teams comprised of 72 people from DRC, Rwanda, and Uganda systematically walked over 1,000 km throughout the entire range and meticulously documented fresh signs of mountain gorilla groups. Genetic analysis of fecal samples collected during the census have identified and corrected for any double-counting of individuals or groups, ensuring the most accurate estimate for the population. Fecal samples were also collected for a comprehensive health screen of the population. Further details and results of the health screen, population structure, genetic composition, mountain gorilla distribution, population dynamics, and human disturbance will be available when the full report is complete in 2011.
According to a statement from the Wildlife agencies of Uganda, Rwanda and DR Congo, the annual growth rate of the gorilla population was estimated at 3.7%.The census team encountered a total of 480 mountain gorilla individuals in 36 groups and 14 solitary silverbacks (adult males) in the Virunga Massif. Of the 480 gorillas, 352 (73%) were habituated, three were solitary males and 128 individuals un habituated. A total of 117 lived in un habituated groups while 11 solitary males had not been habituated.
An earlier census in Uganda’s Bwindi Impenetrable National park in 2006 estimated the mountain gorilla population at 340.