February 2000
The Rwanda Mountain Gorilla is critically endangered. Creative Commons: youngrobv
Note: Because some of the information in this article may be outdated, it has been archived.
While our own population is growing steadily, those of our closest biological relatives, the great apes — the non-human members of the family Hominidae — have slid precariously toward extinction. Over the past half-century:
- The population numbers of three out of our four closest relatives — chimpanzees, bonobos and gorillas — have declined by at least half, earning these species an endangered status from the International Union for Conservation of Nature and Natural Resources (IUCN).1
- The orangutan’s population has slipped between 20 percent and 50 percent over a similar period. Considered vulnerable to extinction in IUCN’s 1996 appraisal, the orangutan is now even worse off — possibly down to half its 1996 numbers — following the past two particularly destructive years of forest fires on the islands of Borneo and Sumatra, and the economic crisis and political unrest that continue to plague Indonesia.10
Population and status of the great apes, 1999
Population sizes of the various species of great apes are tiny fractions of our own.
- Even the most abundant species, the chimpanzee, now numbers well below 200,000 in the wild.6 In the United States alone there are 78 cities with populations greater than that figure.2
- The other three great apes — the bonobo (a genetically distinct species formerly known as the pygmy chimpanzee), the orangutan and the gorilla — are even less numerous. No more than a few tens of thousands of individuals exist, about the equivalent of human population in a medium-sized town. In fact, the number of human beings born each day — some 350,000 — is greater than the current populations of all other great apes combined.
Species, Scientific Name | Population Size | Degree of Threat |
|---|---|---|
subspecies, scientific name | (~ = approx.) | |
Bonobo | 10,000 - 25,0008 | Endangered |
Chimpanzee | 100,000 - 150,000 | Endangered |
|---|---|---|
eastern chimpanzee Pan troglodytes schweinfurthi | More than 5,000 in the Democratic Republic of Congo | Endangered |
~8,000 in Uganda, Rwanda, Burundi and Tanzania6 | Endangered | |
central chimpanzee Pan troglodytes troglodytes | ~80,000, chiefly in Gabon and Congo. Parts of habitat still not surveyed.6 | Endangered |
western chimpanzee Pan troglodytes verus | No more than 12,0006 | Endangered |
Gorilla Gorilla gorilla | 40,000 - 65,000 | Endangered |
|---|---|---|
mountain gorilla Gorilla gorilla beringei | ~6507 | Critically Endangered |
Grauer’s gorilla Gorilla gorilla grauerii | ~17,000 (8,600 - 25,500)8 | Endangered |
western lowland gorilla Gorilla gorilla gorilla | 30,000 - 40,0007 | Endangered |
Human | ~6.0 billion | Not Threatened |
|---|---|---|
*estimated before 1997-98 fires; present pop. could be from 25,0009 to as low as 15,00010 | ||
Sumatran orangutan Pongo pygmaeus abelii | ~17,50011* | (subspecies not evaluated) |
Borneo orangutan Pongo pygmaeus pygmaeus | ~31,00011* | (subspecies not evaluated) |
Orangutan | ~38,500* | Vulnerable* |
|---|---|---|
*estimated before 1997-98 fires; present pop. could be from 25,0009 to as low as 15,00010 | ||
Sumatran orangutan Pongo pygmaeus abelii | ~17,50011* | (subspecies not evaluated) |
Borneo orangutan Pongo pygmaeus pygmaeus | ~31,00011* | (subspecies not evaluated) |
Learning from our relatives
Much of what science has learned about human physiology and behavior comes from observations of primates, particularly of the apes. This is hardly surprising; more than 98 percent of human DNA is identical to that of chimpanzees and bonobos.3 Yet like selfish big brothers in a dysfunctional family, humans are these animals’ greatest threat. Some experts believe that the growing bushmeat trade — the uncontrolled harvesting of wildlife, and the butchering and marketing of their meat — could eliminate all viable populations of African apes within the next 50 years.4 Despite the acute problem of hunting pressure, the clearing of forest may yet prove the ultimate undoing of efforts to save ape species.
Today Homo sapiens is the greatest of the great apes. Humans share the greatest responsibility for these species’ demise, and can reap the greatest benefits for conserving them. But unless we fully understand this greatness, a day may come when — beyond the walls of zoological parks and laboratories — we are the only living member of our Hominid family.
Actionbioscience.org Editor’s Note: The bushmeat trade is the greatest threat facing great apes. According to Peter Walsh of the Wildlife Conservation Society, “we’re not talking about starving villagers needing meat. This is heavily organized commercial poaching where money is the motivation.”1 A 1998 report, by the Ape Alliance, based on several field studies over a decade, shows that:2
- bushmeat is a worldwide activity, affecting great apes and other protected species in Asia, South/Central America, and Africa
- the bushmeat trade is prevalent in Africa, e.g., 5% to 7% of chimpanzee and gorilla populations are killed each year in the Republic of Congo
- several thousand apes are killed, by some estimates, in west and central Africa
- one conservationist’s study estimated that 1 metric ton of smoked bushmeat was unloaded every day at a railway station in Cameroon
1) Friend, Tim. 2002. “Warfare on gorillas.” USA Today, July 8.
2) Ape Alliance. 1998. “African Bushmeat Trade — A recipe for extinction.” Available online at http://www.4apes.com/bushmeat/report/bushmeat.pdf
© 2000, Population Action International (PAI). Reprinted with permission. From the PAI report, Nature’s Place: Human Population and the Future of Biological Diversity and restructured to conform to this Web site’s format. See reprint policy.
