Orangutans plan their trips in advance, without Siri

Sumatran orangutans plan their trips through the Indonesian jungle in advance, according to a new paper published in PLOS ONE that once again upends humans's uniqueness in the animal kingdom.

Perry van Duijnhoven/AP
Male orangutans call their planned routes to females as they travel through the Indonesian jungle.

Sumatran orangutans plan their trips through the Indonesian jungle in advance, according to a new paper published in PLOS ONE. The new research upends yet again the belief that humans are unique in the animal kingdom, suggesting that orangutans, like humans, can plan for the future, at least to some degree.

“There are many scientists (mainly working on human cognition) assuming that only humans are capable of thinking about the future,” said Karin Isler, a researcher at the Anthropological Institute and Museum in Zurich, Switzerland and a co-author on the paper, said in an email interview.

But, according to this latest research, that isn’t the case, with orangutans joining us in planning their routes with forward-thinking aplomb – and without the gentle guidance of Apple’s Siri.

Orangutans, the red-haired, big-bellied primates, have often roiled prevailing theories of what makes a human a human, flagrantly displaying abilities that remind us of, well, us.

In a 2003 paper, published in Science, researchers reported that orangutans exhibited what could be construed as “culture,” proposing that separate groups of animals’ unique rituals were not just adaptive strategies suited to their different environments, but were cultural practices. Then, a 2006 paper, also published in Science, found that captive orangutans and chimpanzees can choose and store tools and then remember to use them 14 hours later.

Studies have also found orangutans to be adroit at deceiving each other, picking up linguistic skills, and making decisions based on reciprocity.

But whether or not orangutans can plan their routes in advance has been unclear. The distinction between orangutans truly planning ahead, as opposed to just acting on their immediate needs, is difficult to tease out.

“Many animals know where they are heading, but it's difficult to say whether these plans are beyond their current motivation (e.g. being hungry or thirsty, and moving directly to a food or water source),” says Dr. Isler.

Over a period of five years, researchers from the Anthropological Institute and Museum at the University of Zurich collected 1,169 long calls from flanged male orangutans in Suaq Balimbing, a peat swamp forest in Gunung Leuser National Park in Indonesia. (“Flanged” means that the orangutans are sexually mature and can emit calls using their throat pads.)

About 696 of those calls, emitted on 320 days, came from a dominant male, the orangutan that commands female attention in his group, as opposed to the unfortunate, submissive males who do not win the hearts of girl orangutans.

The researchers found that flanged, dominant male orangutans emit long calls in the direction of their planned travel route, emitting a new call before each change in direction. The orangutan’s commitment to its called direction held true even after a night’s rest, proving that the calls did not represent immediate needs but long-term plans, the authors say. If an orangutan sounded a directional call at night and then went to sleep, it would resume travel in the direction indicated the night before upon waking the next morning. In fact, the orangutan would continue in that direction for 22 hours after the directional call was given.

“These findings therefore indicate that flanged male Sumatran orangutans make their travel plans at least a day in advance and announce them through their spontaneous long calls,” write the scientists, in the paper. “He remembers the main travel direction in the face of numerous distractions, sometimes lasting for hours, or even overnight.”

The paper authors also note that orangutan’s directional planning differs from that exhibited in migrating birds and homing pigeons, as the orangutan is capable of changing his route and destination throughout the trip.

These calls have an audience: female orangutans. The researchers propose that the females use the dominant male’s calls to tail their preferred mates and avoid the lower-status male orangutans pining for them. After hearing the call, females moved closer to the dominant, call-emitting males, remaining within earshot, the researchers found. The subordinate males, however, plodded away from the stronger male’s given destination.

The researchers do not identify the mechanisms responsible for the planning, noting that the position of the sun, a mental map, or some form of magnetic orientation abilities could be factors in the orangutan’s route mapping. And the results do not necessarily suggest that orangutans are like humans in setting distant goals and pondering the future.

“Planning travel routes does not directly allow for inferring other planning abilities,” says Isler.

The researchers expect that route planning abilities could be found in apes and other large-brained animals. Still, proving that to be true will be complicated, as other animals, unlike the orangutan, might not be so vocal about their plans, the authors write.

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Orangutans plan their trips in advance, without Siri
Read this article in
QR Code to Subscription page
Start your subscription today