Impact case study database

Orangutans are a flagship species endemic to the tropical rainforests on the islands of Borneo and Sumatra, Indonesia and the only great apes of Asia. They play a vital role in maintaining the health of the forest ecosystem, which hosts other important large species, including tigers, Asian elephants and Sumatran rhinos. Unfortunately, due to illegal wildlife trade and rapid deforestation, their numbers have fallen significantly. Research by Davila Ross has made a significant contribution to the conservation of the only remaining orangutan populations in the world. Specifically, her research has contributed to the identification of a new species of orangutan that is now protected under international law and conservation actions plans. Additionally, Davila Ross has co-developed methods to enhance successful rates of rehabilitation programmes for ex-captive and displaced orangutans.

The confirmation of Pongo tapanuliensis as a new species of orangutan ( R4) was the first discovery of a new living great ape species in nearly a century. It is considered to be one of the most significant scientific findings in the past 5 years and was a runner up in Science Magazine’s Breakthrough of the Year in 2017 ( S1). Crucially, this discovery was made in time to prevent the Tapanuli orangutans from becoming extinct. In December 2017, upon receipt of the research report ( R4) and in view of the estimate that only 800 individual animals remained, the International Union for Conservation of Nature included the Tapanuli orangutan in the Red List of Threatened Species as ‘Critically Endangered’ ( S2). At that time, the IUCN predicted a population decline of up to 83% within three generations and inevitable global extinction of the Tapanuli orangutan if no conservation actions were taken ( S2).

As a result of IUCN Red List inclusion, a portfolio of conservation actions have been put in place to help ensure continuity of the species and its habitat. These include:

• International legislation regulating trade: The Tapanuli orangutan is included within Pongo abelii in Appendix 1 of the Convention on International Trade in Endangered Species (CITES). CITES is an international agreement between governments that seeks to prevent unsustainable exploitation of wild fauna or flora from international trade. In general, all international commercial trade in species listed in CITES Appendix 1 is banned. There are currently 183 Parties signed up to the Convention including the European Union (EU), Russian Federation, United States of America, China and Indonesia. Additionally, all countries within the EU are bound by further trading prohibitions and restrictions under European Commission Regulation (EU) 2019/2117 that directly references species in CITES Appendix 1.

• International advocacy to prevent destruction of Tapanuli habitat: In 2018, North Sumatra Hydro Energy (NSHE) submitted plans to develop a hydroelectric power plant in the only known habitat of the Pongo tapanuliensis - a small area of only 1,500km² within the Batang Toru Ecosystem, North Sumatra. This area is divided into three distinct forest habitats. Protection of these areas, as well as the maintenance and extension of corridors between them, is vital to the survival of the species. The submitted plans for the power plant would have isolated one of the areas, limited the options for reconnecting the other two and would have impacted upon nearly 10% of the total population of P. tapanuliensis. Research commissioned by the Indonesian Government resulted in the inclusion of wildlife management measures into the proposals, including building of orangutan bridges, planting of fruit trees in key locations, monitoring and evaluation of the Tapanuli orangutans and regular anti-poaching patrols ( S3). Nevertheless, the proposal was met with widespread international objection including publications in prestigious global media and academic outlets ( S4) and an international Change.org petition ( S5) calling for the Bank of China, a major investor in the project, to withdraw funding. This petition had been signed by over 1,300,000 people by 31 December 2020. In October 2019, the IUCN SSC Primate Specialist Group on Great Apes made an international appeal for a moratorium on any hydroelectric power development in the Tapanuli orangutan range ( S6). In April 2020, the IUCN published the Batang Toru Hydropower Project Fact Check that ‘ identifies specific assertions made by NSHE and assesses them against the best scientific knowledge available’ ( S7). In March 2019, the Bank of China ‘noted the concerns expressed by some environmental organisations’ and announced it would re-evaluate its support for the project. Most recently ( July 2020), a decision has been taken to delay the project for three years , allowing further time for studies to assess the impacts of the project on the Tapanuli orangutan.

• Conservation action plans: In 2017, the Sumatran Orangutan Conservation Programme (SOCP) - a collaboration between the Indonesian Nature Conservation Authority and the international conservation organisation PanEco - launched a monitoring programme to protect the Tapanuli organutans. There are now five dedicated full-time members of staff employed at the Batang Toru Monitoring Station ( S8). Also, in April 2019, the IUCN called for the adoption of a conservation management plan, for the designation of a further 8,000ha of the Bantang Toru Ecosystem as “Conservation Forest” to protect and extend the connecting corridors, and for a moratorium on any projects that might impact the habitat or viability of the Tapanuli orangutan ( S9).

Sustaining orangutan populations also relies on successful rehabilitation-release programmes. These programmes offer ex-captive or displaced orangutans an opportunity to return to the wild. However, the overall mortality rate for released orangutans can be high (Russon et al., 2009), particularly as rehabilitant animals may have very different sets of skills due to early experiences in life. In 2011, following a number of unsuccessful orangutan rehabilitations, [text removed for publication] sought Davila Ross’ expertise on individual fitness-related behaviours in great apes to improve release survival rates. Since 2014, Davila Ross visited [text removed for publication] on six occasions, using these opportunities for research collaboration, training and meetings with staff and wildlife authorities.

As a result, Davila Ross and [text removed for publication] co-developed methods to measure individual characteristics of orangutans. In 2017, these were incorporated into decisions taken by [text removed for publication] to select five release candidates. Between August 2017 and May 2019, Davila Ross trained eight [text removed for publication] staff to systematically record individual survival skills and behaviours to assess individuals’ release potential and to identify areas where improvement in survival skills is needed. In 2018, and based on research led by Davila Ross, [text removed for publication] implemented a new programme of transitional release. The programme places rehabilitant individuals in a pre-release site, where they can learn from their conspecifics prior to full release into the [text removed for publication] Wildlife Reserve. Released orangutans are then followed for a further year. Between April and September 2019, Davila Ross trained four [text removed for publication] staff in coding of orangutan behaviours and seven orangutans were released into the transitional site in May 2019. This system means that it is possible to determine, within a short time period and in a pre-release setting, if the orangutans are ready for full release. According to the Wildlife Officer, [text removed for publication] ‘ the new, softer release approach that considers the individual orangutan skill development helps to increase survival rates. Research undertaken with Dr Davila Ross has enabled us to introduce new policies and strategies that continue to improve release methods, reducing the risk of unsuccessful releases and ultimately reducing the likelihood of death for this critically endangered species’ ( S10).