The BOS Foundation is on a mission to release as many ready orangutans as possible from its two rehabilitation centres into the wild, where they can breed naturally in the forest. However, while in a centre, female orangutans are fitted with birth control implants to prevent captive births. This is to enable female orangutans the best chance at passing all levels of the rehabilitation process and to ensure they are not burdened with raising an infant in the wild when they are first released and still adjusting to life in the forest.

Orangutans at our centres who fall into the ‘unreleasable’ category are also fitted with birth control implants. Usually, the implants are fitted at the first sign of menstruation in young female orangutans. The implant we used is called Levonorgestrel and must be replaced every three years.

Recently, our veterinary team, assisted by technicians, replaced the birth control implants in Tyson (28) and Nania (22), who reside in a special care unit (SCU) complex. The SCU complex is for orangutans who have suffered from zoonotic diseases, such as tuberculosisTyson and Nania first had birth control implants fitted in 2010. This is their fourth replacement implant.


Tyson and Nania will also soon be transferred to an SCU socialisation enclosure, where they will join male orangutans. There, Tyson and Nania will get the chance to move around and exercise more to get them back to an ideal weight.

Fitting birth control implants begins with sedation of the orangutan, who is then weighed. Our veterinary team will also perform other medical checks while the orangutan is under sedation, including blood tests, X-rays, and the taking of sputum samples.

While the orangutans who reside in an SCU complex will likely never be released, unlike their healthier peers, we still endeavour to provide them with the best care possible and a comfortable life that suits their special needs.

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