Apes are highly intelligent primates, captivating human interest with their complex behaviors and close genetic ties to our species. Understanding their current status involves examining global population numbers. While these figures fluctuate, estimating populations provides a baseline for comprehending their presence across various ecosystems. This article defines apes, details their estimated numbers, and discusses influences on their wild populations.
Defining Apes
Apes are primates distinct from monkeys, identified by their lack of tails. They possess larger brains relative to body size and exhibit a more upright posture. Apes are classified into two main categories: Great Apes and Lesser Apes.
Great Apes include chimpanzees, bonobos, gorillas, orangutans, and humans. Lesser Apes comprise the gibbon family, which consists of 20 species. Most non-human Great Apes are found in sub-Saharan Africa, except for orangutans, which are native to Southeast Asia. All gibbon species are found exclusively in Asia.
Global Ape Population Estimates
Estimates for wild ape populations vary by species. Chimpanzees (Pan troglodytes), found across 21 African countries, number between 150,000 and 300,000 individuals. The central chimpanzee, Pan troglodytes troglodytes, accounts for about 140,000 individuals. Bonobos (Pan paniscus), found only in the Democratic Republic of Congo, have a wild population estimated from 10,000 to 50,000 individuals.
Gorilla populations are divided into two species: Eastern and Western. Western Gorillas (Gorilla gorilla) number around 316,000. This includes the Western Lowland Gorilla (Gorilla gorilla gorilla), with estimates from 95,000 to 316,000, and the critically endangered Cross River Gorilla (Gorilla gorilla diehli), with only 250-300 individuals remaining. Eastern Gorillas (Gorilla beringei) have a smaller overall population of approximately 5,000 individuals. The Mountain Gorilla (Gorilla beringei beringei) population was estimated at around 1,060 in 2019, while Grauer’s Gorilla (Gorilla beringei graueri) numbers approximately 3,800 to 6,800 individuals as of 2021.
Orangutans, the only Great Apes in Asia, comprise three species. The Bornean Orangutan (Pongo pygmaeus) is estimated to have a population between 70,000 and 100,000. The Sumatran Orangutan (Pongo abelii) population is considerably smaller, around 13,800 to 15,000 individuals. The Tapanuli Orangutan (Pongo tapanuliensis) is the most recently recognized and rarest, with fewer than 800 individuals. Gibbons, the Lesser Apes, consist of 20 recognized species across Asia; a single total population estimate for all species is not readily available.
Factors Influencing Ape Populations
Ape population numbers are shaped by environmental and human-related influences. Habitat alteration is a primary driver, including deforestation, agricultural expansion for crops like palm oil, and logging activities, which reduce and fragment ape living spaces. Mining operations also contribute to habitat loss and degradation.
Direct human impact affects ape populations. Poaching for bushmeat and the illegal wildlife trade, including the pet trade, contribute to mortality and population declines. Disease outbreaks, such as the Ebola virus, have devastated ape populations, particularly gorillas.
Climate change is a concerning influence on ape habitats. Rising temperatures and altered rainfall patterns can lead to increased frequency of extreme events like droughts and wildfires. Researchers project that African Great Apes could lose a substantial portion of their suitable habitat by 2050 due to these pressures. These factors contribute to the precarious state of ape populations globally.