A shock­ing new report by the Wildlife Con­ser­va­tion Soci­ety (WCS) and Fauna & Flora Inter­na­tional (FFI) doc­u­ments a cat­a­strophic col­lapse of the world’s largest great ape– the Grauer’s gorilla — due to a com­bi­na­tion of ille­gal hunt­ing around min­ing sites and set­tle­ments, prior civil unrest, and habi­tat loss.

The results of the report point to a 77 per­cent drop in gorilla num­bers, from an esti­mated 17,000 in 1995 to just 3,800 indi­vid­u­als today. Grauer’s goril­las — the world’s largest gorilla sub­species weigh­ing up to 400 pounds — are closely related to the bet­ter known moun­tain gorilla. The sub­species is restricted to east­ern Demo­c­ra­tic Repub­lic of Congo (DRC).

The sur­vey was led by experts from WCS and FFI, with field data gath­ered from across the Grauer’s gorilla range by a group of col­lab­o­rat­ing orga­ni­za­tions. The report, funded by the Arcus Foun­da­tion, analysed data col­lected with sup­port from Crit­i­cal Ecosys­tem Part­ner­ship Fund, KfW (Ger­man Devel­op­ment Bank), The Insti­tut Con­go­lais pour la Con­ser­va­tion de la Nature (ICCN), Newman’s Own Foun­da­tion, Rain­for­est Trust, UNESCO, USAID, U.S. Fish and Wildlife Ser­vice, and World Bank. Results were pre­sented at a press con­fer­ence in Kinshasa.

Crit­i­cally Endan­gered
The authors of the report say that their find­ings jus­tify rais­ing the threat­ened sta­tus of the Grauer’s gorilla (Gorilla beringei ssp. graueri) from the cur­rent Endan­gered to Crit­i­cally Endan­gered on the IUCN Red List of Threat­ened Species™, high­light­ing the per­ilous posi­tion these great apes are in, and the need to act now to pre­vent a fur­ther decline in num­bers. This would put all four gorilla sub­species in the crit­i­cally endan­gered cat­e­gory, the high­est cat­e­gory ranking.

Civil war in the DRC
The decline in Grauer’s goril­las can be traced back to the Rwan­dan geno­cide in 1994, which forced hun­dreds of thou­sands of refugees to flee to the DRC. This in turn led to the DRC civil war in 1996, which con­tin­ued until 2003 with dev­as­tat­ing con­se­quences, includ­ing an esti­mated 5 mil­lion peo­ple killed. But beyond the human tragedy, the war has also taken its toll on the DRC’s wildlife as a result of inse­cu­rity, height­ened ille­gal bush­meat trade and increased deforestation.

The authors of the report sought to assess the impact of the civil war on Grauer’s gorilla num­bers, which were esti­mated at 17,000 before the con­flict. Field teams con­ducted wide­spread sur­veys, the most inten­sive ever for this ape, in regions beset by inse­cu­rity, search­ing for ground nests and other signs of this elu­sive ape. In addi­tion, the authors employed a novel method that allowed them to rig­or­ously assess data col­lected by local com­mu­nity mem­bers and rangers to esti­mate Gorilla abundance.

The sur­vey results con­firmed their worst fears: num­bers had plum­meted to an esti­mated 3,800 indi­vid­u­als — a shock­ing 77 per­cent decline.

DRC pro­tected areas. Image credit WCS, ICCN, FFI. . .

DRC Occu­pancy map for Grauer’s gorilla using sta­tis­ti­cally sig­nif­i­cant cli­mate and phys­i­cal covari­ables, and spa­tial effects accord­ing the iCAR model. Image credit WCS, ICCN, FFI.

Arti­sanal min­ing for coltan
One of the pri­mary causes of the decline in Grauer’s gorilla num­bers has been the expan­sion in arti­sanal min­ing for coltan (a key min­eral used in the man­u­fac­ture of cell phones and other elec­tron­ics) and other min­er­als in the gorilla’s range. Most of these arti­sanal min­ing sites are remote, which means that the min­ers often turn to local wildlife for food. Although pro­tected by law, goril­las are highly prized as bush­meat due to their large size and because they are eas­ily tracked and killed as they move in groups on the ground in their small home ranges.

Turn­ing the tide
The authors say that halt­ing and revers­ing the decline of Grauer’s gorilla will take con­sid­er­able effort and will require more fund­ing than is cur­rently avail­able. Arti­sanal min­ing must be con­trolled and the var­i­ous armed groups that con­trol mines dis­armed. To accom­plish this, it will be nec­es­sary to halt min­ing in pro­tected areas, as it is known that min­ers sub­sist on bush­meat and hunt goril­las around their camps.

Three areas are now par­tic­u­larly cru­cial for the gorilla’s sur­vival: Kahuzi-​Biega National Park, the adja­cent Punia Gorilla Reserve where WCS is sup­port­ing local com­mu­ni­ties to estab­lish the reserve and man­age and pro­tect goril­las, and the remote unpro­tected Usala For­est which has no sup­port cur­rently. The Ito­mbwe Reserve and the Tayna regions also sup­port highly-​important out­ly­ing pop­u­la­tions. It is crit­i­cal to for­mally gazette the Ito­mbwe and Punia Gorilla Reserves, which have com­mu­nity sup­port but whose bound­aries are not yet legally established.

Park guards con­tinue to be at risk. On March 31^st, a guard was killed by armed rebels in an ambush in the for­est of the high­land sec­tor of Kahuzi Biega National Park, the only site where the study found goril­las were increasing.

Plumptre added, “Sig­nif­i­cantly greater efforts must be made for the gov­ern­ment to regain con­trol of this region of DRC. In par­tic­u­lar, the gov­ern­ment needs to quickly estab­lish the Ito­mbwe Nat­ural Reserve, sup­port local-​community man­age­ment of the Punia Gorilla Reserve, rein­force Kahuzi-​Biega National Park efforts, and estab­lish strong coor­di­na­tion between ICCN and the DRC mil­i­tary to tackle armed mili­tias that con­trol ille­gal min­ing camps in Grauer’s gorilla heartland.”

Stu­art Nixon of FFI (now at Chester Zoo where he has con­tin­ued his analy­sis of the sur­vey data), one of the co-​authors involved in the study stated, “Grauer’s gorilla is found only in the east­ern Congo — one of the rich­est areas on our planet for ver­te­brate diver­sity. As one of our clos­est liv­ing rel­a­tives, we have a duty to pro­tect this gorilla from extinc­tion. Unless greater invest­ment and effort is made, we face the very real threat that this incred­i­ble pri­mate will dis­ap­pear from many parts of its range in the next five years. It’s vital that we act fast.”

Aer­ial photo of Kahuzi Biega Park. Image credit WCS.

Radar Nishuli, Chief Park War­den for the Kahuzi Biega National Park and another co-​author, said: “What we have found in the field is extremely wor­ry­ing. We are urg­ing a strong and tar­geted response that addresses the fol­low­ing: Train, sup­port and equip eco­guards to tackle poach­ing more effec­tively; build intel­li­gence net­works, and sup­port the close daily mon­i­tor­ing of gorilla fam­i­lies to ensure their pro­tec­tion; engage cus­tom­ary chiefs who hold tra­di­tional power in the region to edu­cate their com­mu­ni­ties to stop hunt­ing these apes.”

Co-​author Jef­fer­son Hall, staff sci­en­tist at the Smith­son­ian Trop­i­cal Research Insti­tute said, “the bright spot in all this is that we have seen, over and over again, ded­i­cated Con­golese con­ser­va­tion­ists risk their lives to make a dif­fer­ence,” Hall added. “Thanks to these indi­vid­u­als, there is still hope and the oppor­tu­nity to save these ani­mals and the ecosys­tems they represent.”

(Source: WCS press release, 04.04.2016)