Nine Sumatran orang utans arrived in Medan yesterday after they were rescued from illegal wildlife trading networks and repatriated from Malaysia to Indonesia. They comprised four males and five females, aged around six to seven years old and weighing 15kg to 20kg each.

Another two orang utans which were also smuggled illegally from Indonesia were recently returned from Thailand, arriving in Jambi on Thursday. All 11 orang utans will be eventually released into the Bukit Tigapuluh National Park in Jambi and Jantho National Park in Aceh, said Mr Irzal Azhar, head of the technical department at North Sumatra Natural Resources Conservation Agency, according to The Jakarta Post.

Orang utans are poached illegally from forests for food, to obtain infants for the domestic and international pet trade, or for traditional medicine. There are estimated to be only around 100,000 Bornean orang utans left in the wild, according to the World Wildlife Fund, while only about 7,500 Sumatran orang utans are thought to remain.

In addition to illegal poaching, populations have crashed because of habitat destruction due to large-scale logging and replacement of forests with cash crops such as oil palm, reported Agence France-Presse.