Shifting apes: Conservation and welfare outcomes of Bornean orangutan rescue and release in Kalimantan, Indonesia

For more than 50 years, Critically Endangered Bornean orangutans (Pongo pygmaeus) have been rescued from poachers or captors, rehabilitated, and released into natural habitats. Wild orangutans are also translocated-intentionally captured from habitat patches and insecure situations for the purpose of releasing them into areas considered to be safer. Although these activities are widely applied, data on orangutan conservation and welfare effects are lacking. Our study improves understanding of these outcomes through analysis of Bornean orangutan rescues and releases conducted in Kalimantan, Indonesia between 2007 and 2017. We collected data on orangutan rescues (n = 1517) and releases (n = 1219) from rescue facility reports, newspaper articles, and scientific publications, and assessed outcomes in relation to action plans, international standards for wildlife releases, law enforcement, and wild orangutan population and habitat conservation. High levels of orangutan killing and illegal possession drove rescue facility intake, while deforestation, actual or potential human-orangutan interactions, and fires drove large-scale wild orangutan translocations. We found rescue facilities held 1112 orangutans in 2017, a number largely unchanged since 2007 despite 1219 reported releases including 605 ex-captive orangutans and a minimum of 523 translocated wild orangutans. Rescue has not facilitated notable changes in law enforcement, nor forestalled wild orangutan losses. Translocations in particular pose serious risks to conservation of orangutan metapopulations and individual welfare. Substantial changes in law enforcement, human attitudes and behaviors toward orangutans, and improved management of human-orangutan coexistence are needed to disrupt the current cycle of orangutan killing and illegal possession followed by rescue and release. These changes would enable a much-needed renewed focus on protecting wild orangutans in their natural habitats.