Stepping into the Ebo forest in Cameroon, the chatter of neighboring villagers gives way to silence.

A guide and sometimes hunter, Betrand Ngansou, slashes through the thick canopy, slowly making his way along a trail muddied by recent rains and marked with tracks of antelope and porcupine. Shrieks can be heard in the distance. “That is probably the chimps,” Ngansou says. “For those of us living here, it’s impossible not to love that sound.”

The 580 square miles of lowland rainforest, 424 square miles of which is part of a proposed national park, would seem an ideal refuge for the 11 primate species living there, including endangered Preuss's red colobus monkeys, Cross River gorillas and one of biggest populations of Nigeria-Cameroon chimpanzees.

But just along the western edge of the proposed park, there are signs of trouble. Stakes are planted in the ground and a nursery nearby is filled with oil palm seedlings. This is part of an ambitious plan by Azur, a Cameroonian palm oil company, to develop a 123,000-acre palm oil plantation next to the reserve. The project could possibly overlap with the forest in some places.

“This would be a disaster,” says Ekwoge Abwe, who oversees the Ebo Forest Research Project with the help of village volunteers and funding from San Diego Zoo Global, the U.S. Fish and Wildlife Service and other groups.

“If this takes place, you would have so many people, cheap labor, coming from all over the country,” Abwe says. “The habitat would be chopped down and, in addition, with so many of the people who come in, there will be more hunting … exacting more pressure on species and leading to population declines and local extinctions. For those species that are not resilient, it means the end for them.”

Cameroon is among a growing list of African nations hoping to follow in the steps of so-called “Asian tigers” like Malaysia and Indonesia, which have made hundreds of billions of dollars by converting huge tracts of rainforest into palm oil plantations. The two Southeast Asian countries produce about 85 percent of the world’s palm oil.

Demand for palm oil—used in everyday products such as dish soap and candy—is set to double by 2030 and triple by 2050. Since available land for palm oil in Southeast Asia is expected to run out in the next decade, Africa has become a target of Asian multinational agribusiness companies looking to expand their reach.

Where governments envision money in their coffers and economic development for impoverished villages, conservationists see an impending environmental disaster, especially for primates. They argue that lax regulations, widespread corruption and the palm oil industry’s poor environmental record could result in these companies repeating the destructive practices seen over the past two decades in Southeast Asia. There, habitats for orangutans, elephants and tigers are being destroyed and land-clearing fires, which cloak parts of the region in haze, have become a routine hazard.

“Palm oil started in Africa and was exported to Asia and became a huge commodity there. It’s coming back to Africa and it’s a deep concern,” says Douglas Cress, the program coordinator for the United Nations’ Great Apes’ Survival Partnership, adding that all three of the non-human great ape genera reside in Africa.

“You can see how quickly and without a doubt what has happened in Asia to not just the habitat of orangutans, but also the habitat of thousands and thousands and thousands of species—and what has happened to quality of life in those countries near plantations,” Cress says. “You have all the knock-on effects of environmental degradation and climate change issues.”

Primates are particularly vulnerable because as many as 80 percent live outside protected reserves in Africa, according to the International Union for Conservation of Nature (IUCN). Their numbers have fallen drastically over the past two decades largely due to the bush meat trade, clearing of rain forests and diseases such as Ebola.

Global Forest Watch shows Equatorial Palm Oil’s claimed expansion area overlapping with Senkwehn National Park in Liberia.

In Western equatorial Africa, the endangered central chimpanzees and the critically endangered western lowland gorillas have been especially hard hit. More than 90 percent of the great apes inhabiting a stretch of land extending from northeastern Gabon to western Congo died from outbreaks of the Ebola virus between the 1990s and 2005, according to a 10-year, IUCN regional action plan approved this year to help stem the decline.

While the majority of plantations in West Africa are still in the early stages of development, several studies have suggested development on the scale seen in Asia would wipe out forests that are home to primates, posing a greater threat than mining or logging, which are more narrowly destructive.

A study last year in Current Biology by primate biologist Serge Wich and his colleagues, who analyzed the potential impact of palm oil development on Africa’s great apes, found that around 59 percent of current palm oil concessions overlap with ape distribution and that about 40 percent of suitable palm oil areas eyed for development are found where apes live but are currently unprotected.

Almost all the areas most suited for palm oil in Liberia (96 percent), Sierra Leone (86 percent), Congo (81 percent) Gabon (80 percent) are prime habitat for great apes. Hardest hit would be western lowland gorillas, which could lose as much as 74 percent of their habitat, and bonobos, which could lose as much as 99.2 percent.

The IUCN, using data from British-based environmental group Earthsight, found that palm oil already covers 1,000 square kilometers of Central Africa and that 1 million square kilometers in the region are suitable for the crop. The plantations would represent 92 percent of the forestland in Congo and 74 percent in the Central African Republic.

“Our great concern is increased fragmentation of habitat so we are ending up with very isolated populations of primates so they will become genetically less healthy,” says Tatyana Humle, a lecturer and researcher at the Durrell Institute of Conservation and Ecology at the University of Kent and a co-author on the Current Biology paper.

Global Forest Watch shows palm oil concessions encroach upon Odzala Kokoua National Park in Congo.

“There won’t be as much gene flow between them and also, if a lot of areas they depend on for food are being wiped out, we will see primates foraging on crops and increasing human-primate conflict in some of these areas,” she says.

Almost all the agribusiness companies working in Africa have their roots in Asia, including several companies accused of environmental crimes in Indonesia and Malaysia.

Probably the most controversial project thus far in Africa is a 1.2-million-acre plantation in Congo being developed by Atama, a subsidiary of Wah Seong Corporation Berhad, a Malaysian oil and gas infrastructure company.

It is by far the largest palm oil plantation in Congo. Several environmental groups including Greenpeace, Earthsight and Rainforest Foundation UK contend that much of the land designated for the plantation is primary forest, which is home to chimpanzees and gorillas and, in some places, abuts the Ntokou-Pikounda National Park. If completed, they say, it would double deforestation in the country.

Satellite images provided by Global Forest Watch, a monitoring service overseen by the World Resources Institute, also found that the Atama concessions overlap with Ntokou-Pikounda.

Atama, which on its website promotes the economic benefits of its project, doesn’t mention biodiversity or whether it would ensure that high-value forest isn’t cut down for the planation. The company did not respond to a request for comment.

Another Asia-based firm, Olam International, is developing a 250,000-acre plantation on about 741,000 acres of land with the government of Gabon that Earthsight claims is on high-value forest that includes great ape habitat. Olam, however, denies the claim, insisting it will only put the plantation on “land that is classed as savannah mosaic, woody pioneer areas, logged or degraded forest that does not support significant conservation priorities,” and it is working with authorities to develop an ape management plan that aims to “safeguard ape populations wherever they are found.”

Wilmar International, a Singapore-based company that bills itself as Asia’s biggest agribusiness group, has come under fire for several of its plantation projects in Nigeria. In a July report, Friends of the Earth together with Environmental Rights Action-Nigeria claimed that the company’s plantations will replace rainforest that provides habitat for Preuss's red colobus monkeys, drills, chimpanzees and Cross River gorilla. The group also said Wilmar is accelerating deforestation in concessions that overlap the Cross River National Park and the Ekinta Forest Reserve, based on mapping done in May.

Wilmar denies the claims, saying that four of its Nigerian estates are on sites of former plantations that date back decades and that it was still doing environmental assessments on the remaining four. Noting that, “responsible palm oil production can play an important role in improving the lives of the local communities,” Wilmar says it is working with the government to ensure its plantations don’t overlap with the national park.

Environmentalists are fighting on several fronts in Cameroon, where the government has pledged to expand palm oil production by more than 26 percent by 2018 as part of an effort to become a top exporter in Africa. That means an additional 25,000 acres of new plantations each year.

A Cameroonian company, Safacam, is developing plantations that appear to overlap with two reserves, according to Global Forest Watch. Greenpeace also claims that Sud-Cameroun Hevea, a company owned mostly by Singapore’s GMG, is developing rubber and palm oil plantations that threaten the Dja Faunal Reserve, a UNESCO World Heritage site and one of the largest and best protected rainforests in Africa.

The Ebo forest is among the most at risk simply because it lacks the protection and funding of a national park like Dja Faunal. Even without the palm oil, it faces a myriad of other threats, from raids by bush meat hunters trapping and shooting primates, antelopes and elephants, to incursions from illegal loggers and miners prospecting for iron ore.

The Cameroonian government acknowledges the conservation benefits of Ebo but thus far has delayed plans to designate it as a national park. Part of its hesitation is due to opposition from local residents, some of who once lived inside the forest and hope to return one day. Now, with the arrival of Azur, talk of increased protection appears to be losing out to demands for development.

Ngansou and other villagers in the area have embraced the planned palm oil plantations as a welcome addition to a region that mostly survives on growing cassava, bananas, yam and coco, as well as the declining bush meat trade. The plantation could provide good paying jobs and improve conditions in the villages lacking electricity, clean water and indoor plumbing, the government and the company said, and will be located far from the reserve.

For the bespectacled Abwe, it’s hard to argue against jobs, but he hasn’t given up hope the plantation can be pushed back.

Abwe is joined by concerned villagers who formed a group called Club des Amis des Gorilles. They hike through the forest removing hunter’s snares and gathering what information they can on elusive primates. And when they are not in the forest, Abwe and the villagers show visitors photos and videos of the animals that could disappear should the forest be destroyed.

“We are just trying to encourage people to conserve what is left,” Abwe said. “Many villagers depend on the forest for their livelihood. If all the biodiversity goes, there will be nothing left for them.”

The reporting for this story was supported by the Mongabay Reporting Network Program.