A worker of Sumatran Orangutan Conservation Programme carries a tranquilized Sumatran orangutan as it's being prepared to be released into the wild at a rehabilitation center in Kuta Mbelin, North Sumatra, Indonesia, Friday, July 10, 2015. The orangutans at the center were mostly rescued from palm oil plantations or confiscated from homes where they were kept as pet animals. Orangutan populations in Indonesia's Borneo and Sumatra island are facing severe threats from habitat loss, illegal logging, fires and poaching. Conservationists predicted that without immediate action, orangutans are likely to be the first great ape to become extinct in the wild. (Photo by Binsar Bakkara/AP Photo)

A worker of Sumatran Orangutan Conservation Programme put tranquilized Sumatran orangutans on a cart as they are being prepared to be released into the wild at a rehabilitation center in Kuta Mbelin, North Sumatra, Indonesia, Friday, July 10, 2015. (Photo by Binsar Bakkara/AP Photo)

A worker of Sumatran Orangutan Conservation Programme stand near a holding cage at a rehabilitation center in Kuta Mbelin, North Sumatra, Indonesia, Friday, July 10, 2015. (Photo by Binsar Bakkara/AP Photo)

An approximately 8 year-old male orangutan named Siamang reacts under the influence of tranquilizer as it's being prepared to be released into the wild at a rehabilitation center in Kuta Mbelin, North Sumatra, Indonesia, Friday, July 10, 2015. (Photo by Binsar Bakkara/AP Photo)

Sumatran orangutans sit inside a holding cage at Sumatran Orangutan Conservation Programme's rehabilitation center in Kuta Mbelin, North Sumatra, Indonesia, Friday, July 10, 2015. (Photo by Binsar Bakkara/AP Photo)

A worker of Sumatran Orangutan Conservation Programme carries a tranquilized Sumatran orangutan as it's being prepared to be released into the wild at a rehabilitation center in Kuta Mbelin, North Sumatra, Indonesia, Friday, July 10, 2015. (Photo by Binsar Bakkara/AP Photo)

A worker of Sumatran Orangutan Conservation Programme wheels a tranquilized Sumatran orangutan as it's being prepared to be released into the wild at a rehabilitation center in Kuta Mbelin, North Sumatra, Indonesia, Friday, July 10, 2015. (Photo by Binsar Bakkara/AP Photo)

A worker of Sumatran Orangutan Conservation Programme examines a tranquilized Sumatran orangutan as it is being prepared to be released into the wild at a rehabilitation center in Kuta Mbelin, North Sumatra, Indonesia, Friday, July 10, 2015. (Photo by Binsar Bakkara/AP Photo)