Research by van Schaik et al., published in PLOS ONE, provides new evidence of long-term planning behavior by an animal in the wild. In a study of Sumatran orangutans, van Schaik and colleagues found that the direction of long calls made by flanged* males predicted travel directions up to 22 hours in advance, even when the call and travel were interrupted by sleeping at night. The authors found that, in contrast to migrating birds, the orangutans adjust their travel plans and often signal this change with new spontaneous long-calls, which predict travel direction better than their initial long-calls. The authors point to the female orangutans’ desire to mate with and be protected by the dominant male as a reason why communicating travel information in advance makes sense from a reproductive point of view. The authors posit that orangutans likely make and adjust plans using features of episodic memory–the ability to recall specific events–however more research is required to understand the mechanism behind this behavior. Overall, the authors suggest that this type of long-term planning behavior by animals in the wild is unlikely limited to orangutans and they expect this behavior to exist in other apes and large-brain animals.
*“Sexually mature males may, after highly variable periods of time, grow cheek flanges (wide cartilaginous pads at the sides of their face.”
- van Schaik, C. P., Damerius, L., & Isler, K. (2013). Wild Orangutan Males Plan and Communicate Their Travel Direction One Day in Advance. PLOS One, 8(9), e74896.