As many as 60 percent of nonhuman primates, our closest biological relatives, face extinction due to human activities, including logging, hunting, and agricultural expansion, according to a new study.
The study published in Science Advance, found that the loss of habitat due to agriculture expansion have affected over 70 percent of primate species, while other factors including road construction, oil drilling, and mining also have an impact. Humans directly inhibit primate development by encroaching on their habitats because of the growing need of housing and resources. The primates affected include lemurs, chimpanzees, gorillas, and orangutans.
“Habitat destruction and human overpopulation are their greatest threats,” said Matthew Kessler, the Associate Director of the Division of Laboratory Animal Resources at West Virginia University.
Richard Rawlins, former director of Cayo Santiago, a colony off the coast of Puerto Rico designated for monkey research, said that logging has led to the decline of tree species important to primates as food and shelter.
“Commercial logging for hardwoods in both the Amazon and also in the subtropical Asian forests have decimated primate habitats as well,” said Rawlins.
Many primates are killed and their bodies are used for oil palm products Demand for such products has specifically caused the decline of Sumatran and Bornean orangutans, amongst other great ape populations.
“The ones at greater risk are the great apes—gorillas and chimps are both highly threatened in their environment by human activity destroying habitat and by poaching,” says Rawlins.
The study found that the bushmeat trade is also a driving force for primate population decline. This term refers to the illegal hunting of wildlife for meat, where people actually eat primates including apes, according to Kessler. Scientists suspect that around 150,000 primate carcasses are traded every year for meat and income.
“In my opinion, not much can be done to stop the bushmeat trade,” Rawlins said, “A lot of African animals are being lost just to feed the populations.”
Climate change is also threatening primates. While some species can migrate to better areas, others that are surrounded by humans and dwindling forests are trapped. Those forests are torn down for human use, such as roads and agriculture. Various diseases are also taking a toll on primate species. The problem is “not just habitat destruction, but also disease, which is probably also due to close interactions in humans,” Kessler says.
The study concludes that it is not too late to counteract the impending extinction of primate species. Solutions to protect primate populations, such as stopping illegal trade and reducing human footprints in primate populations are possible.
At the same time, researchers are finding new primate species they’ve never seen before. “The number of primate species now recognized has increased dramatically across the past 50 years,” says Joe Erwin, a professor of anthropology at George Washington University.
The new species, however, do not change the absolute number of living primates.
“As humans continue to invade natural habitats and previously unoccupied species, more will be discovered, yet more will be lost,” Rawlins said.
Even though new species are being found, humans are not doing anything to protect the primates. “The same problems will exist for the newly discovered species,” Rawlins said.