The Mountain gorilla (Gorilla beringei beringei), population in Uganda’s Bwindi Impenetrable Forest National Park and Sarambwe Nature Reserve, in the Democratic Republic of Congo, has increased to 459 according to latest census results released Monday.
While releasing the results, Uganda’s Outgoing Tourism, Wildlife & Antiquities Minister, Prof. Ephraim Kamuntu noted that these latest figures when combined with results from an earlier study in nearby Virunga Massif, suggests the global population of the primates has grown to 1,063.
“The Mountain Gorilla Census conducted in the Bwindi-Sarambwe ecosystem and the one conducted in the Virunga Massif before that, are excellent testament to the importance of transboundary collaboration as envisaged the Greater Virunga Transboundary Collaboration (GVTC) treaty,” Kamuntu said.
“In an area encompassing Bwindi Impenetrable National Park, Uganda, and Sarambwe Nature Reserve, DRC, an area of 340 km2, 459 individual gorillas were found in 50 groups with 13 solitary individuals,” he added.
This is compared with an estimated 400 individual gorillas in 36 groups and 16 solitary individuals from a survey of the same area in 2011.
Kamuntu was however quick to add that, “habitat loss, poaching and zoonotic diseases remain leading threats to the survival of mountain gorillas.”
As in the previous mountain gorilla census conducted in the Virunga Massif, survey teams walked pre-determined “recces” (reconnaissance trails) ensuring a thorough coverage of all forest areas to sweep the Bwindi-Sarambwe and search for signs of gorillas, other key mammals, and human activities.
Trek East Africa Safaris understands that when fresh gorilla signs were detected, the teams followed the gorilla trail to locate three recent night nest sites. At each of these nest sites, the teams collected fecal samples from nests. The process was completed twice; first from March to May 2018 (62 days) and second from October to December 2018 (60 days). A second sweep was conducted so as to allow the team find gorillas that were undetected during the first sweep and thus provide more reliable numbers of gorillas. Fecal samples were analyzed genetically to determine individual genotypes.
The survey teams also collected data on signs and sightings of select mammals, such as chimpanzee and elephants, and human activities, such as snares or tree cutting. While exercising caution due to the limitations of the study, there were no indications of declines in populations for the select mammals surveyed, including elephants, since 2011.
But in a sign of the threat, survey teams found 88 snares while carrying out their work. The primates were reclassified last year by the International Union for Conservation of Nature from critically endangered to endangered.
Speaking to Trek East Africa Safaris, Prof Kamuntu observed that Uganda used to thrive on revenues from the three Cs (Coffee, Cotton and Copper). “Not anymore,” he said, adding that Mountain Gorillas are the biggest foreign exchange earners to the coffers of Uganda Wildlife Authority, contributing up to 60% of its revenue.
On his part, Dr Akankwasa Barirega, commissioner wildlife at Uganda’s Tourism Ministry, when asked on what could have caused the increase in gorilla families, he said that it could have been as result of a number of factors, among which the maturation of black backs to silverbacks thereby forming their own families or fights between Silverbacks to form different families.
He said that the bottom line was to improve the census methods so that they include both traditional counts and genetic analysis.
“Going forward, the genetic analysis should be in triplicates so that samples are sent to three independent laboratories to ensure triangulation of data,” he said.
Dr Gladys Kalema-Zikusoka, founder of Conservation Through Public Health also weighed in saying, “We are very grateful for the continued support of all our partners in conservation, donors and local communities living around mountain gorilla habitats, which has enabled increased law enforcement, wildlife monitoring, veterinary care and meaningful community engagement through improved health care, sustainable tourism and other alternative livelihood options. Without you, this positive growth trend in mountain gorillas would not have been achieved which has led to their IUCN status changing in 2018 from Critically endangered to Endangered.”
This is the fifth population count for this area, and the first to include Sarambwe Nature Reserve.
The survey was conducted by the Protected Area Authorities of Uganda and DRC (Uganda Wildlife Authority and l’Institut Congolais pour la Conservation de la Nature, respectively) under the framework of the Greater Virunga Transboundary Collaboration with support from Rwanda Development Board and funding from Fauna & Flora International, WWF, and Partners in Conservation at the Columbus Zoo & Aquarium.