Orangutans Make Travel Plans Like Humans to Navigate the Jungle

Humans aren't the only ones that make travel plans. It turns out that apes also look ahead when they move. Wild male orangutans not only plan their travels, but also communicate these plans to other orangutans. The findings reveal that these great apes can look forward to the future.

While researchers have known that orangutans can plan for future needs, they've been unsure whether great apes employ this behavior in the wild. In order to find out, the scientists studied the calls of orangutans living in dense, tropical forests. There, orangutans are often out of sight of the apes from the rest of their group.

Orangutans are loud, and male orangutans are louder still. They can howl noisily enough to be heard almost a mile away. Usually, this call is used to establish their status among other males, though it can also be used to signal to females. The researchers tracked these loud calls, recording over 200 of them made by 15 adult males.

In the end, the scientists found that the males faced the direction they planned to travel before emitting the "long calls" in that direction the night before a journey. If they changed travel plans the following morning, males often followed up with a call in the new direction planned.

"We found that males emitted long calls mostly facing the direction they travelled a few hours later, or even after a night's rest," said Karin Isler, co-author of the new study, in a news release.

The calls were apparently effective for communicating these plans, too. Females within earshot of the call usually followed the path taken by the male and even changed direction when the male did. In contrast, subordinate males who heard the call tended to avoid following a similar path.

Currently, scientists aren't exactly sure why orangutans plan their trips in advance. However, it could be an adaptation to avoid a known rival or search for mates. In addition, these planning abilities might not just be limited to orangutans; they might also be used by other apes and large-brained animals.

The findings are important not only for understanding a bit more about orangutan behavior, though. They could also aid conservation efforts in the future. Learning more about orangutans could allow conservationists to better target areas to protect.

The findings are published in the journal PLOS One.