Mating behaviour is one of the most important forms of social interaction in the life of orangutans. This interaction occurs between male and female individuals and plays a vital role in ensuring the survival of a species that is increasingly threatened with extinction. Wild orangutans typically reach sexual maturity between the ages of 14–18. However, in rehabilitated individuals, sexual maturity is suspected to occur earlier due to various environmental factors and past life experiences.

Bugis and Mori: A Story of Gradual Courtship in the Wild

An interesting observation came from a male orangutan named Bugis and a female named Mori. These two individuals were once housed together in the same enclosure prior to their release into the wild. Their release sites were intentionally chosen to be close to one another, allowing continued social interaction and ensuring a safe release process for the field team.

Once the enclosure doors were opened, Bugis immediately approached Mori. Just as with wild orangutans, his approach was gradual. Bugis followed Mori’s movements, both when she climbed trees and when she moved across the forest floor.

Female Response and Gradual Social Approaches

In some cases, female orangutans may show avoidant behaviour when approached by a male. The exact reasons behind this are not yet fully understood, but it is considered a natural part of their social dynamic. When the approach is successful, the male will usually initiate physical contact as a form of positive social interaction.

In Bugis and Mori’s case, Bugis gently touched Mori’s back and embraced her from behind as part of his courtship behaviour. He also displayed investigative behaviour before attempting copulation. Additionally, when not in close proximity to Mori, Bugis was observed making long calls to attract her attention.

Reproduction: A Complex and Gradual Social Process

Observing orangutan mating behaviour directly in the wild is a valuable experience for researchers and field observers. This process shows that reproduction in orangutans is not instant, it involves complex and layered social interaction.

In the context of conservation, the ability of orangutans to form pair bonds and reproduce naturally in the wild is a significant indicator of successful rehabilitation. By preserving their natural habitats and providing safe living spaces, we increase the chances of witnessing the birth of a new wild-born generation, individuals who grow up with fully natural instincts, abilities, and survival skills.

Text by: Biodiversity-PRM Team, PT. RHOI at Kehje Sewen Forest, East Kalimantan