The census of the Virunga Volcanoes mountain gorilla population carried out during September and October 2003 has shown a 17% increase in population size since 1989. Their number is now estimated as a total of 380 gorillas.

Six teams had traversed the entire gorilla habitat range, searching for fresh signs of gorilla groups. Their night nest are used to establish the number of gorillas in each group. A total of 100 team members participated in the census, drawn from the staff of the protected area authorities and their partners.

The census was carried out in three national parks; Parc Nationale des Volcans of Rwanda, Virunga National Park in the Democratic Republic of Congo (DRC) and Mgahinga National Park of

269 gorillas were counted in 16 habituated groups, 80 gorillas in 12 unhabituated groups and 11 solitary silverback males. Among the unhabituated animals, several infants potentially were missed as they slept together with their mothers in the same nest; or even whole groups might have been missed. Therefore, this number was corrected and the total number was calculated – 380 gorillas. 71% of these animals is habituated (1989 this was the case only in 57%).

The Virunga gorilla census was possible thanks to the close collaboration of the conservation authorities in the three countries, the Office Rwandais de Tourisme et Parc Nationaux, the Institut Congolais pour la Conservation de la Nature and the Uganda Wildlife Authority. It was supported by the International Gorilla Conservation Programme, the Wildlife Conservation Society, the Dian Fossey Gorilla Fund – International, the Institute of Tropical Forest Conservation (Mbarara University of Science and Technology), the Dian Fossey Gorilla Fund – Europe, Berggorilla & Regenwald Direkthilfe, the Mountain Gorilla Veterinary Project, and the Max Planck Institute for Evolutionary Anthropology.

Information from a press release by the national park authorities of Uganda, Rwanda and the Democratic Republic of the Congo (January 2004). The final census report has not yet been published.