2015 – State of Great Apes: Chimpanzee
Chimpanzees survival status in the wild 2015 became more of a mystery in the aftermath of the 2014 Ebola chaos that swept across West Africa’s Sierra Leone, Liberia, and Guinea. Historically we know when all Ebola mortality is summed together, an estimated one third of the world’s gorillas and chimpanzees have been killed by this disease. So what was the impact on chimpanzees from this latest outbreak?
Even without the added complication of Ebola, chimpanzees populations have a wide, but sadly fragmented distribution across Equatorial Africa. Populations occur from southern Senegal across the forested belt north of the Congo River to western Uganda and western Tanzania, from sea-level to 2,800 meters (9,240 feet.) They are the most wide-ranging non-human great ape, with an equally broad diet and habitat. The four subspecies of chimpanzee (Pan troglodytes) recognized by IUCN are distributed across central and west Equatorial Africa as follows:
P. t. verus (Schwarz, 1934) is found in West Africa from Senegal to Nigeria.
P. t. ellioti (Gray, 1862) is found only in Nigeria and Cameroon, north of the Sanaga River.
P. t. troglodytes (Blumenbach, 1799) ranges from Cameroon, south of the Sanaga River, to the Congo River/Ubangi River (Democratic Republic of Congo).
P. t. schweinfurthii (Giglioli, 1872) ranges from the Ubangi River/Congo River in Central African Republic and the Democratic Republic of the Congo, to western Uganda, Rwanda and western Tanzania.
In the past 30 years chimpanzees, while numerous compared to other great apes, have continued to see their populations fragment, isolate, and plummet. Once abundant — some estimate the total population at over 1 million as recently as 1950 — conservative estimates now place the population at less than 200,000. Their climb up the endangered list has been alarmingly unwavering over the past 20 years:
2007–Critically Endangered (CR)
Most alarming is that in 2015 we simply have little knowledge about where chimpanzees stand in the wild. According to IUCN, “population estimates are crude.” An example of this is for the Nigerian/Cameroonian chimpanzee P. t. ellioti where best guesstimates range from as low as 2,500 to as high as 9,000. Therefore any legitimate conservation planning by GRASP, WWF, WCS  or others major international conservation groups remains pie-in-the-sky guesswork.
A combination of factors has led to a poor understanding of the current population status of chimpanzees: much of the range has not been surveyed, survey methods have been inconsistent, and many of the surveys are now out of date. Older survey data are particularly unreliable as Ebola, commercial hunting and extractive industries are known to have caused dramatic declines in some areas. And now a new threat is poised to threaten chimpanzees further, palm oil plantations. If judging by the flow of orphans into Pan African Sanctuary Alliance member sanctuaries across Africa is any indication chimpanzees face a bleak future in the wild.
2015 also proved chimpanzees remain under serious threat from illegal international trade to the Middle East, China and Russia. The one international organization entrusted with preventing this illicit trade, CITES, has proven itself woefully impotent, with a Secretary-General, John Scanlon, unwilling to confront internal and external UN powers in order to ensure CITES protects chimpanzees.
Perhaps the one bright spot for chimpanzees came not in the wild, but with their captive cousins. The National Institutes of Health (NIH) announcement that it is retiring all government research chimps to sanctuaries.
Photo P1130606 – rescued female chimpanzee “Lada”, at Limbe Wildlife Center, Cameroon
Notes & Sources
2] GRASP = Great Ape Survival Programme; WWF = World Wildlife Fund; WCS = Wildlife Conservation Society
2015-2016 Global research and reporting on great apes made possible in part through the generous financial support of the Philadelphia Zoo