WILD VERSUS REHABILITATED
Not all orangutan behaviours are the same. One significant difference lies between wild and rehabilitated orangutans. Although they belong to the same species, their different life experiences play a significant role in shaping their unique behaviour.
A key distinction is that rehabilitated orangutans tend to have a greater tolerance for humans. This trait develops because rehabilitated orangutans are used to interacting with humans from an early age, whether during rescue operations, medical treatment, or daily care at rehabilitation centres.
In addition, those born in rehabilitation centres require more time and specific training to develop proper foraging behaviours. In contrast, wild orangutans generally possess more extensive and instinctual knowledge of natural food sources in the forest.
Struggle building nests
Another notable difference lies in their ability to build nests. Wild orangutans learn this skill directly from their mothers. Rehabilitated orangutans, however, often struggle with nest-building at first. They must learn by observation during their time in Forest School. This learning experience also shapes their social behaviour: Naturally semi-solitary animals, rehabilitated orangutans often exhibit higher levels of social interaction.
Lesan (here with her second baby) is one of the first orangutans released by the BOS Foundation to the Kehje Sewen Forest in 2012.
While wild-born orangutans acquire survival skills directly from their mothers in their natural habitat, orangutans born in rehabilitation centres grow up in a human-modified environment. As a result, they lack early-life experiences that reflect the complexity of wild living. Therefore, they develop their behaviour through structured learning processes rather than instinct or maternal rearing.
Equal survival capabilities
Nevertheless, orangutans raised in rehabilitation centres and those brought up in the wild show relatively equal survival capabilities. One example is Lesan (photo), who BOS released in 2012. She has survived in the wild to this day and given birth to two offspring, whom she successfully taught to survive in the forest.
Understanding the behavioural differences is crucial for designing effective release and post-release monitoring programs. This knowledge also helps conservation teams tailor training stages to ensure that orangutans are truly ready to survive in the wild.
As a testament to the success of our rehabilitation program, BOS has successfully released 549 orangutans to date. From these releases, we have recorded 36 wild births.
Find out more about our orangutan conservation work here.
