The Mountain Gorillas which are known to be critically endangered world over and usually explored on gorilla safaris in Uganda and Rwanda always undergo census every after a period of five (5) years in an attempt to ascertain their current population.
Unlike the humans who have got established settlements, the Mountain Gorillas thrive in dense forested habitats perched on high altitude hills and highlands which prompt some individuals including those on Uganda gorilla safaris to wonder how the Mountain gorilla census is carried out.
Also if compared to other wildlife census which majorly feature identifying small areas for survey and then the few animals counted are multiplied proportionally based on the area size where such species reside, the Mountain Gorilla census stands as a rather a complicated and a time consuming activity.
The Mountain Gorilla census do not include physically finding and counting each Mountain Gorilla but instead it features traversing the forest in quest of gorilla nest sites and trails. The gorilla forest is mapped into sectors which are thoroughly covered by the technical field assessors who are spaced to not more than 500m in between. For example, in the recently concluded Mountain Gorilla census in the Virunga volcanoes, a range of six (6) teams of field assessors were employed to traverse the massif on the side of Uganda, Rwanda and Democratic Republic of Congo to gather the required data.
The Mountain Gorilla movements and structures are keenly followed to avoid double counting since they keep rotating in the forest. Some of the trails followed are among the ones used by travelers on gorilla trekking in Rwanda Uganda and Congo in search of these Great Apes. The trails followed are not more than five (5) days old and faecal samples are collected from the nests.
Upon coming across Mountain Gorilla dung, the assessors measure its size which helps to ascertain the age class of the owner namely; Infants, Juvenile or Adult as it is believed that the larger the dung size, the older the gorilla. And the presence of Silver hair in the dung demonstrates that it must have come from a Silverback. But for further analysis, the dung is taken using wooden sticks and stored in a test tube awaiting a DNA test. The assessors have to put on gloves to avoid contaminating the dung with the DNA of humans.
The collected samples are forwarded to the laboratory where the wildlife scientists analyse each of them and it is this process that ensures that every Mountain Gorilla is counted once. This is a long process that takes several months to accomplish which explains why we are still waiting for the results of the recently conducted Mountain Gorilla Census in the Virunga massif.
Based on 2010 results, the Mountain Gorilla Population in the world is given at 880 individuals of which 400 of these were recorded to thrive in Uganda gorilla trekking safari tour destination of Bwindi Impenetrable National Park and the rest in the Virunga massif protected by Volcanoes National Park on the Rwandan side, Virunga National Park on the side of Congo and Mgahinga Gorilla National Park on the side of Uganda.