George Schaller the gorilla researcher carried out the first census of the gorilla population in the Virungas in 1959-1960. He estimated that the total number could be between 400 to 500 individuals within the Virunga Conservation area. The following census was done by the Dian Fossey Karisoke team between 1971 and 1973 which showed a dramatic decline in numbers, down to 250 gorillas. One of the reasons behind this fall is that Volcanoes National Park lost 40 percent of its size to agricultural cultivation and at the same time poaching of gorillas was on the increase. In 1978 another census done by the Karisoke Centre counted about 260 gorillas, with forty two infants below three years as a good sign.
After the death of Dian Fossey on 27th December 1985, the Census of the Population of mountain gorillas in 1989 continued and it was found out that there were approximately 324 Gorillas in the Virunga Conservation Area and 320 in Bwindi Impenetrable Forest.
In 2003, another gorilla census was carried out in the Virunga massif and estimated the gorilla population to be 380 individuals. Measures of conservation have since been carried throughout the major three gorilla countries and a positive result has been yielded according to the last census in 2010.
In March and April 2010, a recent census of mountain gorillas in the Virunga Massif was carried out and showed that the area had 480 individual Gorillas which showed that there had been a 26.3% increase in the population over the past seven years (2003-2010) and an encouraging sign that conservation efforts are succeeding within the area.
These 480 individual gorillas were in 24 habituated groups with 352 (73%) gorillas (349 in groups and 3 solitary males), 12 unhabituated groups with 128 individuals (117 in groups and 11 solitary males).
This population made a remarkable recovery from the approximately 250 individuals that existed only three decades ago. This recovery is due to the conservation efforts of many organizations and institutions in the three major countries of Democratic Republic of Congo, Rwanda and Uganda. Organizations under these efforts are: International Gorilla Conservation Programme (IGCP), African Wildlife Foundation (AWF), Fauna & Flora International, and the World Wide Fund for Nature.
The main objective of the gorilla census was to establish an update on total population size in the Virunga massif and to compare with the previous censuses. There was also need to determine the level of the human disturbance, survey for diseases and take fecal samples for genetic analysis on the gorillas.
In Bwindi, the census has been carried differently with the first census in 1997 which revealed 300 gorillas, in 2002 with 320 individuals which showed an increase in the numbers. However, due to increase in poaching and death of mountain gorillas, the number decreased to 302 according to the 2006 census and as of now, the world is looking forward to the 2011 census of the Bwindi - Sarambwe population of mountain gorillas which was carried out in September to October 2011.
In 2006 the total number of mountain gorillas was 682 between Virunga and Bwindi national park. In 2012 we estimate a total population of 820 gorillas between Virunga and Bwindi.
