What are “Unreleasable” Orangutans?

At the BOSF orangutan rehabilitation centers, hundreds of rescued orangutans are prepared for release to natural forests where they can live wild and free. The long rehabilitation process is necessary to help orangutans develop the natural skills and behaviors required for survival, and it can take many years to complete.

Sadly, not all orangutans complete the rehabilitation process as expected. Those who were in captivity for too long prior to rescue or who have spent too long in human care generally have difficulty in developing their natural behaviors. There are also some orangutans suffering from infectious diseases such as tuberculosis or hepatitis B and C that are susceptible to relapse at any time. There are also orangutans who have physical disabilities that inhibit their development, thus eliminating the possibility of their release in the forest.

We refer to these orangutans as the 'unreleasables'. Those with underdeveloped natural skills are placed on sanctuary islands where they are monitored and given supplementary food. These individuals have the opportunity to live in a forest-like environment. Due to limited space on sanctuary islands, some of the BOSF unreleasable orangutans have to be placed in
enclosures. Meanwhile, those orangutans suffering from recurring diseases are cared for in a special quarantine complex, to prevent transmission to the healthy orangutan population.

The unreleasable orangutans are representative of the other side of animal rehabilitation. While we aim to reintroduce as many orangutans as we can back to the forest, the reality is that, of the over 400 orangutans currently cared for by the BOS Foundation, well over 100 individuals will likely never be able to return to natural forests.

Many of these orangutans have health problems such as obesity, psychological disorders, or exhibit stereotypic behaviors; all attributed to their past trauma prior to rescue. Orangutan Outreach is supporting the preparation of larger island sanctuaries, so that these orangutans get the chance to spend time in habitats that closely resemble a natural forest and live as
nature intended - in the treetops.

There is always the possibility, however small, that some of these orangutans make behavioral progress significant enough to warrant their release in the forest. We continue our work, hoping for this miracle so that every orangutan can live free in their true home, the forest.