Macrocosm: When the Map Expands: A Look into the Tapanuli Orangutan

ANDREW WALMSLEY/MINDEN PICTURES

In 2017, after 20 years of study, documentation, paperwork, and grit, the scientific community officially declared Erik Maijaard's discovery of a new species: Pongo tapanuliensis, the Tapanuli orangutan. The Tapanuli orangutan resembles its cousins, the Bornean and Sumatran orangutan, in body build and fur color, but it has frizzier hair, a smaller head, and a flatter face. Unlike Bornean orangutans, where only males have beards, both male and female Tapanuli have wispy orange beards. Females of the species stay with their young for up to a decade and usually only have three babies in a long, healthy lifetime.

There are fewer than 800 Tapanuli orangutans in existence, and if seven are removed every year, the species could go extinct within 130 years. Throughout three generations, the species lost 83% of its population.

"You feel a certain amount of responsibility for the animal," says Maijaard. "You describe it, you name it, you put it on the map. It's a bit daft of me to find a population, describe it, and then see it go extinct within my lifetime."

Tapanuli orangutans live on the island of Sumatra, separated by distance and by height from Sumatran orangutans, which live further north on the island. Found almost exclusively in the Batang Toru forest's uplands, scientists hypothesized that the species adapted to the higher elevation. This is highly debated, especially according to recent research by Maijaard and his team of ecologists at Borneo Futures, an independent consultancy company in Brunei. The population may not be in the uplands because it's suited to be there; it may be in the uplands because it has nowhere else to go.

Where did the orangutans go?

A recent study by the company found that Tapanuli orangutans were once prolific all over the island of Sumatra. By analyzing historical records, such as newspapers, journals, and letters written by the people of the island, Maijaard, and his team deduced a historical range for the great apes. And the range he found far exceeded his expectations.

The records of reported sightings extended 300 kilometers south and 100 kilometers northeast of the current range in the 1940s. If that weren't expansive enough, records going back to the 1890s contained sightings as far southwest as 400 kilometers from the current range. With multiple documented sightings of breeding populations within those margins, Maijaard predicts that half of Sumatra's west coast once swarmed with Tapanuli orangutans. The orangutans lived in swampy peat forests, by riverbeds, and in submontane forests - a range identical to that used by their cousins, the Sumatran orangutans. This contrasts with the previously held belief that Tapanuli apes were meant to munch on upland caterpillars.

"It doesn't seem to be that happy on that mountain," Maijaard said. "It changes your perspective of thinking of this highland orangutan species that was specialized to live there. By thinking of it as a highland species, you're totally missing the point."

Maijaard's team conducted this study to determine more about the environmental and anthropogenic factors that were slowly driving these apes to extinction. A typical picture of orangutan conservation usually involves the harvest of palm oil. Perhaps the image of a fleeing orangutan, a falling forest, and a greedy businessman enters your mind at the thought; it's not an uncommon belief and certainly no small part in habitat destruction. But by examining the historical range of this species before massive deforestation ever came to Sumatra, more reasons for population decline become apparent.

Habitat loss and population fragmentation certainly led to groups of these large populations becoming extinct. Severe deforestation by locals was already occurring, even in the early 19th century, to clear the way for smallholder agriculture, livestock, and timber. Hunting may have also been significantly harmful to the woodland populations. Nomadic populations in Sumatra reportedly preferred primate meat over other meat sources and considered primates a delicacy. Orangutan skins and teeth were used in amulets in Sumatra. Alfred Russel Wallace argued that orangutans were common in swamp forests not because of their preference for the area but because humans rarely hunted there.

Orangutans are especially vulnerable to fragmentation, says Maijaard. Female orangutans are philopatric, rarely moving beyond the regions where they have their young. Suppose a hunter shoots a female orangutan as he travels back from a hunt. In that case, the population will be depleted without compensation, as other females won't come to take her place.

What Does This Mean For Tapanuli?

Erik Maijaard detests pessimism. His purpose for looking at the historic range of these apes was not to dissuade conservation efforts or paint a bleak picture of extinction. He instead offers hopes in knowing what caused the fragmentation and extinction of populations and hopes to see a broader understanding as a result of it.

"People don't want to point the finger at the hunters, since they can be our friends in conservation," Maijaard says. "But they're part of the problem and part of the solution. It's not an issue if we direct it head-on. We're not asking people to stop hunting pigs. We can just tell people not to hunt orangutans and not drastically change people's diets."

His greatest enemy now is ambivalence and a misguided narrative: that of the greedy capitalist palm oil salesman being the only cause for population decline. He asserts that both significant deforestation and local problems must be addressed to rescue this critically endangered species, as every orangutan does count when the population's below 800. However, the issue is complex and hazy in many areas.

"The same oil plan that has an environmental issue that we want to address feeds a family in Borneo and sends their kids to school," Maijaard says. "If we just play black and white solutions in politics, we're not going to solve this issue. But if we ask, 'How much would we need to pay a farmer to not shoot an orangutan?', I don't think it's that much. We can influence these things in a community."

The effects of this historical ecology don't only apply to the orangutans. We could use it to observe passenger pigeon dispersal in North America, wolves in the Netherlands, and extinct bird populations in Europe. This method helps pinpoint what causes these quick and drastic extinction events. 

It's about the storytelling, Maijaard says, and the imagination of what once was and what could be again. If we choose to bring back a population, how far back can we bring it? What would it take to make a forest look like it did before farmers touched it or hunters looted it? It all depends on the extent of the action we take now.

For now, perhaps, we can give some money to a Sumatran hunter and ask them not to shoot an orangutan on their way home. And maybe, just maybe, wispy-bearded apes can raise their children in peace.