New research shows that orangutans formulate and share future plans with others in their troop.

Very few animals have revealed an ability to consciously think about the future—behaviors such as storing food for the winter are often viewed as a function of instinct. Now a team of anthropologists at the University of Zurich has evidence that wild orangutans have the capacity to perceive the future, prepare for it and communicate those future plans to other orangutans.

The researchers observed 15 dominant male orangutans in Sumatra for several years. These males roam through immense swaths of dense jungle, emitting loud yells every couple of hours so that the females they mate with and protect can locate and follow them. The shouts also warn away any lesser males that might be in the vicinity. These vocalizations had been observed by primatologists before, but the new data reveal that the apes’ last daily call, an especially long howl, is aimed in the direction they will travel in the morning—and the other apes take note. The females stop moving when they hear this special 80-second call, bed down for the night, and in the morning begin traveling in the direction indicated the evening before.

The scientists believe that the dominant apes are planning their route in advance and communicating it to other orangutans in the area. They acknowledge, however, that the dominant males might not intend their long calls to have such an effect on their followers. Karin Isler, a Zurich anthropologist who co-authored the study in PLOS ONE last fall, explains, “We don’t know whether the apes are conscious. This planning does not have to be conscious. But it is also more and more difficult to argue that they [do not have] some sort of mind of their own.”
1 Capuchin monkeys appear to have a sense of fairness, insisting on receiving as good a food reward as their peers for performing the same job.

2 Scrub jays can relocate food that has been hidden for months and may even remember how long it has been stored. The jays also anticipate potential thefts and will relocate their food if they think another jay has spotted it.

3 Rhesus macaques will not pull a chain that brings them food if they think it will harm a fellow monkey.

4 Male voles may be able to predict when a female will be most fertile and, at the opportune time, revisit the location where she was last seen.

5 Bonobos and orangutans can use tools to retrieve food and then save their tools for later use.

Apes have mid-life crises


Too bad chimpanzees can’t buy sports cars. New research says it’s not just humans who go through midlife crises: Chimps and orangutans also experience a dip in happiness around the middle of their lives.

“There may be different things going on at the surface, but underneath it all, there’s something common in all three species that’s leading to this,” said study leader Alexander Weiss, a primate psychologist at the University of Edinburgh in Scotland.

The study team asked longtime caretakers of more than 500 chimpanzees and orangutans at zoos in five countries to fill out a questionnaire about the well-being of each animal they work with, including overall mood, how much the animals seemed to enjoy social interactions, and how successful they were in achieving goals (such as obtaining a desired item or spot within their enclosure).

The survey even asked the humans to imagine themselves as the animal and rate how happy they’d be.

When Weiss’s team plotted the results on a graph, they saw a familiar curve, bottoming out in the middle of the animals’ lives and rising again in old age. It’s the same U-shape that has shown up in several studies about age and happiness in people.

“When you look at worldwide data, you see this U-shape,” said National Geographic Fellow Dan Buettner, author of Thrive: Finding Happiness the Blue Zones Way.

“It’s different for every country, but it’s usually somewhere between age 45 and 55 that you hit the bottom of the curve, and it continues to go up with age. You see centenarians in good health reporting higher well-being than teenagers.”

(Take Buettner’s True Happiness Test.)

Social and economic hypotheses may partly explain this happiness curve in human lifetimes: Maybe it’s tied to adjusting expectations, abandoning regret, or just getting more stuff as we grow older. But Weiss suspects there may be something more primal going on.

“We’re saying, take a step back and look at the big picture: Is there any evidence that there’s an evolutionary basis underlying this?” said Weiss, whose study was published today in the journal Proceedings of the National Academy of Sciences.

“Knowing that a similar phenomenon exists in human and nonhuman primates opens up the realm of possible explanations.”

Although the stereotype of a midlife crisis is generally negative—feelings of depression or discontentment with one’s life and where it’s headed—Weiss believes such ennui may have an evolutionary upside.

By the middle of one’s life, humans and apes often have access to more resources than when they were younger, which could make it easier to achieve goals. Feelings of discontentment may be nature’s way of motivating us to “strike while the iron is hot,” said Weiss.

“It may feel lousy, but your brain could be tricking you into improving your circumstances and situation, signaling you to get up and really start pushing while you’re absolutely at your prime,” he said. “And I think that’s a really powerful and positive message.”

Knowing that a midlife dip in happiness is a natural—and temporary—part of life could make it easier for humans to cope with the experience, Weiss said. It could also help caretakers improve captive apes’ quality of life, by identifying ages at which the animals might benefit from extra attention or enrichment.

(See pictures of places where people are happiest.)

“I don’t think this totally subsumes other explanations for age-related changes in happiness, but it adds another layer,” Weiss said.

Weiss has previously studied the correlation between personality and happiness in both chimpanzees and humans, and plans to look next at the impact of factors like sex and social groupings.

“I hope this raises awareness of all that we can learn by looking at our closest living animal relatives.”