Comanditaire Venotschap (CV) Global Inter System

Darajati W.

PoRI

Schaik C. P.

Singleton I.

Wich S. A.

Conservation Science and Practice

Wich, S.

Fredriksson, G.

Usher, G.

Kühl, H.

Nowak, M.

MPG.PuRe

P E R S P E C T I V E S A ND NOT E SThe Tapanuli orangutan: Status, threats, and steps for improvedconservationSerge A. Wich1,2 | Gabriella Fredriksson3 | Graham Usher3 | Hjalmar S. Kühl4,5 |Matthew G. Nowak3,61School of Natural Sciences and Psychology, Liverpool John MooresUniversity, Liverpool, UK2Institute for Biodiversity and Ecosystem Dynamics, University ofAmsterdam, Amsterdam, the Netherlands3Conservation Division, The PanEco Foundation - Sumatran OrangutanConservation Programme, Berg am Irchel, Switzerland4Department of Primatology, Max Planck Institute for EvolutionaryAnthropology, Leipzig, Germany5Sustainability and Complexity in Ape Habitat Group, German Centre forIntegrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig,Germany6Department of Anthropology, Southern Illinois University, Carbondale,IllinoisCorrespondenceSerge A. Wich, School of Natural Sciences and Psychology, James Parsons Building, Byrom street, L33AF, Liverpool, UK.Email: s.a.wich@ljmu.ac.ukKEYWORD S : Batang Toru, hydrodam, Tapanuli orangutanEver since the Tapanuli orangutan (Pongo tapanuliensis)was described two years ago (Nater et al., 2017) it has fre-quently been in the news for two primary reasons. First,because of the excitement generated by the discovery of thefirst new extant great ape species since 1929. Second,because of the immediate threat posed to the new species bythe development of a hydrodam to generate electricity(Sloan, Supriatna, Campbell, Alamgir, & Laurance, 2018).As the species has only been described recently there is nopaper that summarizes its status and threats even thoughsome of that information is available from a previous studywhere this species was still considered a population of theSumatran orangutan (Pongo abelii) (Wich et al., 2016). Inthis letter, we aim to remedy this gap by providing a succinctoverview of the status of and threats to the Tapanuli orangu-tan, as well as by identifying key steps toward improvedconservation. This is particularly relevant as there is a needto be able to determine the impact of the hydroelectric damdevelopment which is best achieved from a clear baseline.As with the other two orangutan species, the Tapanuliorangutan is considered to be Critically Endangered by theInternational Union for Conservation of Nature (IUCN)(Nowak, Rianti, Wich, Meijaard, & Fredriksson, 2017). Thespecies is only found in the forests of the Batang Toru Eco-system in the province of North Sumatra, Indonesia(Figure 1). Based on extensive survey work from 2000 to2012 it has been determined that the total extent of its distri-bution covers 1,023 km2 (Wich et al., 2016). It is found inthree main forest blocks with a total of 767 individuals (95%confidence intervals [CI] [231–1,597]): the west blockwhich houses 581 individuals (95%CI [180–1,201] [sum of533, 42, and 6 in Figure 1]), the east block with 162 individ-uals (95% CI [46–341]), and the Sibual-buali Reserve with24 individuals (95% CI [6–53], based on (Wich et al., 2016),with possibly small populations to the north and/or in theLubuk Raya Reserve). Of this distribution, roughly 85% isunder some form of protection status, but 15% is land forother uses (Nowak et al., 2017). The west block and theReceived: 8 February 2019 Accepted: 27 March 2019DOI: 10.1111/csp2.33This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the originalwork is properly cited.© 2019 The Authors. Conservation Science and Practice published by Wiley Periodicals, Inc. on behalf of Society for Conservation BiologyConservation Science and Practice. 2019;1:e33. wileyonlinelibrary.com/journal/csp2 1 of 4https://doi.org/10.1111/csp2.33Sibual-buali Reserve are still moderately connected andorangutan dispersal is expected to occur between those areasbased on the locations where nests have been found duringsurveys (Figure 1). It is less clear if orangutans can stillmove between the west and east block because of the pro-vincial road from Tarutung to Padangsidempuan separatingthese blocks as well as the Batang Toru River.There are several threats to the Tapanuli orangutan.Between 1985 and 2007, 43.3% of the forests in the provinceof North Sumatra (where the Tapanuli orangutan occurs)have been lost (Wich, Riswan, Jenson, Refisch, &Nellemann, 2011). Annual deforestation rates were particu-larly high from 1985 to 1990 (4.2%), decreased from 1990to 2000 (1.2%), and then increased again from 2000 to2008/2009 (2.3%). Particularly recent losses of peat swampareas on the coast where the species had been found in thepast (Wich et al., 2003) have led to a reduction of forest forthe Tapanuli orangutan as well as the slower but steady for-est loss that occurs around all three blocks. During1990-2009, annual forest loss for the area in which theTapanuli orangutan occurs was calculated as 0.11%, with arange of <0.01–0.84% (Wich et al., 2011). This is lowerthan the overall annual forest loss for North Sumatra due tothe Tapanuli orangutan occurring in more mountainous areaswhich have lower deforestation rates than areas at lower ele-vations. The other main threat is killing of orangutans. Thisoccurs in two circumstances. First, orangutan hunting stilloccurs in the area (Wich et al., 2012). Even though huntersdo not seem to go into the forest to specifically hunt fororangutans, they do opportunistically hunt/kill them for foodwhen encountered (Wich et al., 2012). Second, orangutansthat venture into community plantations have been killed asa result of human-orangutan conflict (Nater et al., 2017). Asorangutans are long-lived and have slow reproductive rates,even low levels of extrinsic mortality (i.e., >1% per year,which in this case is just a few individuals) represent a majorthreat to the long-term growth, stability, and persistence ofthe small-sized Tapanuli orangutan populations (Marshall etal., 2009).In addition to these threats there is a hydroelectric damwith associated infrastructure planned in the area (Sloanet al., 2018). The area of influence of the dam is planned inan area with the highest Tapanuli orangutan densities andcovers 5.5% (42 individuals, 95%CI [14–84]) of the totalFIGURE 1 Map showing the distribution of the Tapanuli orangutans, their population numbers and threats. The 95% confidence intervals (CI)for the various areas are: West block: 164–105, East block: 46–341, Hydro AoI: 14–84, Corridor: 2–12, Sibual-buali: 6–532 of 4 WICH ET AL.Tapanuli orangutan population (Wich et al., 2016). Orangu-tans in this area and surroundings will be negatively impactedthrough habitat degradation and loss. This is of particular con-cern for orangutan females because they are philopatric andtend not to move when they lose parts of their home range(van Schaik, 2004) and risk starvation or being killed whenthis occurs. Such home range loss and subsequent dispersalcan also lead to compression of orangutans in adjacent areasand inflated densities past the carrying capacity and hencelead to food shortages and future reductions in density(Husson, personal communication, January 15, 2019). If partsof their home range are lost, orangutans in disturbed areas willhave to use the remaining parts of their own home range moreintensively than before, which can also lead to social tensionbetween females (Ashbury et al., 2015).Additionally, the hydroelectric dam and its associatedinfrastructure will separate the Sibual-buali Reserve from thewest block and will also impact the options for reconnectingthe east and west block. Over 20 km of road and 14 km ofelectricity transmission lines through Tapanuli orangutanhabitat are planned, and at least 3 million m3 of excavatedspoil is planned to be dumped in orangutan habitat(Comanditaire Venotschap (CV) Global Inter System, 2014,2016). Furthermore, it is well-established that infrastructuredevelopment, especially roads, can facilitate human accessinto previously inaccessible areas, eventually leading toadditional and often unrestricted levels of habitat degrada-tion and loss, hunting, and/or human-animal conflict(Laurance, 2015; Laurance & Arrea, 2017; van der Ree,Smith, & Grilo, 2015).Taken together, the hydroelectric project will drive theSibual-buali and Sitandiang corridor population (30 individ-uals, 95% CI [8–65]) and east block population (162 individ-uals) to a status of nonviable, which is defined here as apopulation with 0% probability of extinction and >90%retention of genetic diversity for a minimum of 1,000 years(Singleton et al., 2004; Marshall et al., 2009). Following theresults of the 2004 orangutan Population and Habitat Viabil-ity Assessment (PHVA) workshop, a population of >500individuals is considered viable using this definition (Single-ton et al., 2004). This will leave the west block as the lastremaining viable Tapanuli orangutan population. But giventhe current and projected threats of habitat degradation andloss, hunting, human-orangutan conflict, an expandinggoldmine, and a neutralized logging concession in the area(GoNSP, 2017; MoEF, 2017; MoF, 2014), this is anextremely risky scenario and should therefore be avoided atall costs, because these threats could drive this population tononviable status within as few as 1–2 generations.In conclusion, the Tapanuli orangutan was the latestextant great ape to be discovered, but given its extremelysmall population numbers and current and projected threats,it might well be the first one to go extinct. This would con-travene the Indonesian Law Regarding the Conservation ofBiological Resources and Ecosystems (Law No. 5/1990), aswell as the Aichi targets to which the Indonesian govern-ment has committed (Darajati et al., 2016; PoRI, 1990). Assuch, it is imperative that the Government of Indonesia takessome bold steps to secure its future, of which the mostimportant short-term ones are: (a) to halt the hydroelectricdam development; (b) change the land use status of theunprotected 15% of the area where the Tapanuli orangutanoccurs to a protected status; and (c) establish a corridorbetween the west and east block and improve the corridorbetween the west block and Sibual-buali Reserve. In addi-tion, the ongoing hunting and small-scale deforestation needto be halted through serious enforcement of Indonesia's reg-ulations concerning protected species.CONFLICT OF INTERESTThe authors declare no potential conflict of interest.AUTHOR CONTRIBUTIONSS.A.W., G.F., G.U., and M.G.N. conceived the paper,S.A.W., G.U., M.G.N., and H.S.K. conducted the analyses,S.A.W., G.F., G.U., H.S.K., and M.G.N. wrote the paper.No ethics approval was needed for this study. All data areavailable on request from the authors.ORCIDSerge A. Wich https://orcid.org/0000-0003-3954-5174REFERENCESAshbury, A. M., Posa, M. R. C., Dunkel, L. P., Spillmann, B.,Atmoko, S. S. U., van Schaik, C. P., & van Noordwijk, M. A.(2015). Why do orangutans leave the trees? Terrestrial behavioramong wild Bornean orangutans (Pongo pygmaeus wurmbii) atTuanan, Central Kalimantan. American Journal of Primatology, 77,1216–1229.Comanditaire Venotschap (CV) Global Inter System. (2014). ANDAL:Rencana Pembangunan Pembangkit Listrik Tenaga Air (PLTA)Batangtoru Kapasitas 500 MW Dan Jaringan Transmisi 275 KVDari PLTA Batang toru Sampai Desa Parsalakan Kec. AngkolaBarat Kab. Tapanuli Selatan Prov. Sumatera Utara. Medan,Republic of Indonesia: Perseroan Terbatas (PT) North SumateraHydro Energy.Comanditaire Venotschap (CV) Global Inter System. (2016). AdendumANDAL, RKL-RPL: Rencana Kegiatan Pembangunan PembangkitListrik Tenaga Air (PLTA) Batang Toru Dari Kapasitas 500 MWMenjadi 510 MW (4 x 127.5 MW) Dan Perubahan Lokasi QuarryDi Kabupaten Tapanuli Selatan - Provinsi Sumatera Utara.WICH ET AL. 3 of 4Medan, Republic of Indonesia: Perseroan Terbatas (PT) NorthSumatera Hydro Energy.Darajati, W., Pratiwi, S., Herwinda, E., Radiansyah, A. D., Nalang, V.S., Nooryanto, B., … Hakim, F. (2016). Indonesian biodiversitystrategy and action plan (IBSAP) 2015-2020. Jakarta, Republic ofIndonesia: Ministry of National Development Planning / NationalDevelopment Planning Agency of the Republic of Indonesia.GoNSP. (2017). Peraturan Daerah Provinsi Sumatera Utara, Nomor 2Tahun 2017, Tentang rencana tata ruang wilayah Provinsi Sum-atera Utara tahun 2017-2037. Medan, Republic of Indonesia: Gov-ernor of North Sumatra Province of the Republic of Indonesia.Laurance, W. F. (2015). Bad roads, good roads. In R. van der Ree, D.J. Smith, & C. Grilo (Eds.), Handbook of road ecology (pp. 10–15).New York, NY: John Wiley & Sons.Laurance, W. F., & Arrea, I. B. (2017). Roads to riches or ruin? Sci-ence, 358(6362), 442–444.Marshall, A. J., Lacy, R., Ancrenaz, M., Onnie, B., Husson, S. J.,Leighton, M., … Wich, S. A. (2009). Orangutan population biol-ogy, life history, and conservation. In S. A. Wich, S. S. UtamiAtmoko, T. Mitra Setia, & C. P. van Schaik (Eds.), Orangutans:Geographic variation in behavioral ecology and conservation(pp. 311–326). New York, NY: Oxford University Press.MoEF. (2017). Surat Keputusan Menteri Lingkungan Hidup danKehutanan Republik Indonesia, Nomor: SK.1076/MENLHK-PKTL/KUH/PLA.2/3/2017, Tentang Peta Perkembangan Pen-gukuhan Kawasan Hutan Provinsi Sumatera Utara Sampai Den-gan Tahun 2016. Jakarta, Republic of Indonesia: Ministry ofEnvironment and Forestry of the Republic of Indonesia.MoF. (2014). Surat Keputusan Menteri Kehutanan Republik Indonesia,Nomor: SK.579/MENHUT-II/2014, Tentang Kawasan Hutan Pro-vinsi Sumatera Utara. Jakarta, Republic of Indonesia: Ministry ofForestry of the Republic of Indonesia.Nater, A., Mattle-Greminger, M. P., Nurcahyo, A., Nowak, M. G., DeManuel, M., Desai, T., … Krützen, M. (2017). Morphometric,behavioral, and genomic evidence for a new orangutan species.Current Biology, 27(22), 3487–3498, e3410.Nowak, M. G., Rienzi, P., Wich, S. A., Meijaard, E., & Fredriksson, G.(2017). The IUCN red list of threatened species 2017.Pongo tapanuliensis. https://doi.org/10.2305/IUCN.UK.2017-3.RLTS.T120588639A120588662.enPoRI. (1990). Undang-Undang Republik Indonesia, Nomor 5 Tahun 1990,Tentang Konservasi Sumber Daya Alam Hayati Dan Ekosistemya.Jakarta, Republic of Indonesia: President of the Republic of Indonesia.Singleton, I., Wich, S., Husson, S., Stephens, S., Utami Atmoko, S. S.,Leighton, M.,… Byers, O. (2004). Orangutan population and hab-itat viability assessment: Final report. Apple Valley, MN: IUCN/-SSC Conservation Breeding Specialist Group.Sloan, S., Supriatna, J., Campbell, M. J., Alamgir, M., &Laurance, W. F. (2018). Newly discovered orangutan speciesrequires urgent habitat protection. Current Biology, 28, R650–R651.van der Ree, R., Smith, D. J., & Grilo, C. (2015). The ecological effects oflinear infrastructure and traffic: Challenges and opportunities of rapidglobal growth. In R. van der Ree, D. J. Smith, & C. Grilo (Eds.), Hand-book of road ecology (pp. 1–9). New York, NY: John Wiley & Sons.van Schaik, C. P. (2004). Among orangutans: Red apes and the rise ofhuman culture. Cambridge, MA: Harvard University Press.Wich, S. A., Fredriksson, G. M., Usher, G., Peters, H. H., Priatna, D.,Basalamah, F., … Kühl, H. (2012). Hunting of Sumatran orang-utans and its importance in determining distribution and density.Biological Conservation, 146, 163–169.Wich, S. A., Riswan, J., Jensom, J., Refisch, J., & Nellemann, C.(2011). Orangutans and the economics of sustainable forest man-agement in Sumatra. United Nations Environment Programme(UNEP). Birkeland, Norway: Birkeland Trykkeri AS.Wich, S. A., Singleton, I., Nowak, M. G., Utami Atmoko, S. S.,Nisam, G., Arif, M. S.,… Kühl, H. S. (2016). Land-cover changespredict steep declines for the Sumatran orangutan (Pongo abelii).Science Advances, 2, e1500789.Wich, S. A., Singleton, I., Utami-Atmoko, S. S., Geurts, M. L.,Rijksen, H. D., & van Schaik, C. P. (2003). The status of the Suma-tran orang-utan Pongo abelii: An update. Oryx, 37, 49–54.How to cite this article: Wich SA, Fredriksson G,Usher G, Kühl HS, Nowak MG. The Tapanuliorangutan: Status, threats, and steps for improvedconservation. Conservation Science and Practice.2019;1:e33. https://doi.org/10.1111/csp2.334 of 4 WICH ET AL.

English

The Tapanuli orangutan: Status, threats, and steps for improved conservation

Wich, S.A.

Frederiksson, G.

Kühl, H.S.

Nowak, M.G.

International Migration, Integration and Social Cohesion online publications

UvA-DARE is a service provided by the library of the University of Amsterdam (https://dare.uva.nl)UvA-DARE (Digital Academic Repository)The Tapanuli orangutan: Status, threats, and steps for improved conservationWich, S.A.; Frederiksson, G.; Usher, G.; Kühl, H.S.; Nowak, M.G.DOI10.1111/csp2.33Publication date2019Document VersionFinal published versionPublished inConservation Science and PracticeLicenseCC BYLink to publicationCitation for published version (APA):Wich, S. A., Frederiksson, G., Usher, G., Kühl, H. S., & Nowak, M. G. (2019). The Tapanuliorangutan: Status, threats, and steps for improved conservation. Conservation Science andPractice, 1(6), [e33]. https://doi.org/10.1111/csp2.33General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s)and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an opencontent license (like Creative Commons).Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, pleaselet the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the materialinaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letterto: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. Youwill be contacted as soon as possible.Download date:11 Nov 2022P E R S P E C T I V E S A ND NOT E SThe Tapanuli orangutan: Status, threats, and steps for improvedconservationSerge A. Wich1,2 | Gabriella Fredriksson3 | Graham Usher3 | Hjalmar S. Kühl4,5 |Matthew G. Nowak3,61School of Natural Sciences and Psychology, Liverpool John MooresUniversity, Liverpool, UK2Institute for Biodiversity and Ecosystem Dynamics, University ofAmsterdam, Amsterdam, the Netherlands3Conservation Division, The PanEco Foundation - Sumatran OrangutanConservation Programme, Berg am Irchel, Switzerland4Department of Primatology, Max Planck Institute for EvolutionaryAnthropology, Leipzig, Germany5Sustainability and Complexity in Ape Habitat Group, German Centre forIntegrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig,Germany6Department of Anthropology, Southern Illinois University, Carbondale,IllinoisCorrespondenceSerge A. Wich, School of Natural Sciences and Psychology, James Parsons Building, Byrom street, L33AF, Liverpool, UK.Email: s.a.wich@ljmu.ac.ukKEYWORD S : Batang Toru, hydrodam, Tapanuli orangutanEver since the Tapanuli orangutan (Pongo tapanuliensis)was described two years ago (Nater et al., 2017) it has fre-quently been in the news for two primary reasons. First,because of the excitement generated by the discovery of thefirst new extant great ape species since 1929. Second,because of the immediate threat posed to the new species bythe development of a hydrodam to generate electricity(Sloan, Supriatna, Campbell, Alamgir, & Laurance, 2018).As the species has only been described recently there is nopaper that summarizes its status and threats even thoughsome of that information is available from a previous studywhere this species was still considered a population of theSumatran orangutan (Pongo abelii) (Wich et al., 2016). Inthis letter, we aim to remedy this gap by providing a succinctoverview of the status of and threats to the Tapanuli orangu-tan, as well as by identifying key steps toward improvedconservation. This is particularly relevant as there is a needto be able to determine the impact of the hydroelectric damdevelopment which is best achieved from a clear baseline.As with the other two orangutan species, the Tapanuliorangutan is considered to be Critically Endangered by theInternational Union for Conservation of Nature (IUCN)(Nowak, Rianti, Wich, Meijaard, & Fredriksson, 2017). Thespecies is only found in the forests of the Batang Toru Eco-system in the province of North Sumatra, Indonesia(Figure 1). Based on extensive survey work from 2000 to2012 it has been determined that the total extent of its distri-bution covers 1,023 km2 (Wich et al., 2016). It is found inthree main forest blocks with a total of 767 individuals (95%confidence intervals [CI] [231–1,597]): the west blockwhich houses 581 individuals (95%CI [180–1,201] [sum of533, 42, and 6 in Figure 1]), the east block with 162 individ-uals (95% CI [46–341]), and the Sibual-buali Reserve with24 individuals (95% CI [6–53], based on (Wich et al., 2016),with possibly small populations to the north and/or in theLubuk Raya Reserve). Of this distribution, roughly 85% isunder some form of protection status, but 15% is land forother uses (Nowak et al., 2017). The west block and theReceived: 8 February 2019 Accepted: 27 March 2019DOI: 10.1111/csp2.33This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the originalwork is properly cited.© 2019 The Authors. Conservation Science and Practice published by Wiley Periodicals, Inc. on behalf of Society for Conservation BiologyConservation Science and Practice. 2019;1:e33. wileyonlinelibrary.com/journal/csp2 1 of 4https://doi.org/10.1111/csp2.33Sibual-buali Reserve are still moderately connected andorangutan dispersal is expected to occur between those areasbased on the locations where nests have been found duringsurveys (Figure 1). It is less clear if orangutans can stillmove between the west and east block because of the pro-vincial road from Tarutung to Padangsidempuan separatingthese blocks as well as the Batang Toru River.There are several threats to the Tapanuli orangutan.Between 1985 and 2007, 43.3% of the forests in the provinceof North Sumatra (where the Tapanuli orangutan occurs)have been lost (Wich, Riswan, Jenson, Refisch, &Nellemann, 2011). Annual deforestation rates were particu-larly high from 1985 to 1990 (4.2%), decreased from 1990to 2000 (1.2%), and then increased again from 2000 to2008/2009 (2.3%). Particularly recent losses of peat swampareas on the coast where the species had been found in thepast (Wich et al., 2003) have led to a reduction of forest forthe Tapanuli orangutan as well as the slower but steady for-est loss that occurs around all three blocks. During1990-2009, annual forest loss for the area in which theTapanuli orangutan occurs was calculated as 0.11%, with arange of <0.01–0.84% (Wich et al., 2011). This is lowerthan the overall annual forest loss for North Sumatra due tothe Tapanuli orangutan occurring in more mountainous areaswhich have lower deforestation rates than areas at lower ele-vations. The other main threat is killing of orangutans. Thisoccurs in two circumstances. First, orangutan hunting stilloccurs in the area (Wich et al., 2012). Even though huntersdo not seem to go into the forest to specifically hunt fororangutans, they do opportunistically hunt/kill them for foodwhen encountered (Wich et al., 2012). Second, orangutansthat venture into community plantations have been killed asa result of human-orangutan conflict (Nater et al., 2017). Asorangutans are long-lived and have slow reproductive rates,even low levels of extrinsic mortality (i.e., >1% per year,which in this case is just a few individuals) represent a majorthreat to the long-term growth, stability, and persistence ofthe small-sized Tapanuli orangutan populations (Marshall etal., 2009).In addition to these threats there is a hydroelectric damwith associated infrastructure planned in the area (Sloanet al., 2018). The area of influence of the dam is planned inan area with the highest Tapanuli orangutan densities andcovers 5.5% (42 individuals, 95%CI [14–84]) of the totalFIGURE 1 Map showing the distribution of the Tapanuli orangutans, their population numbers and threats. The 95% confidence intervals (CI)for the various areas are: West block: 164–105, East block: 46–341, Hydro AoI: 14–84, Corridor: 2–12, Sibual-buali: 6–532 of 4 WICH ET AL.Tapanuli orangutan population (Wich et al., 2016). Orangu-tans in this area and surroundings will be negatively impactedthrough habitat degradation and loss. This is of particular con-cern for orangutan females because they are philopatric andtend not to move when they lose parts of their home range(van Schaik, 2004) and risk starvation or being killed whenthis occurs. Such home range loss and subsequent dispersalcan also lead to compression of orangutans in adjacent areasand inflated densities past the carrying capacity and hencelead to food shortages and future reductions in density(Husson, personal communication, January 15, 2019). If partsof their home range are lost, orangutans in disturbed areas willhave to use the remaining parts of their own home range moreintensively than before, which can also lead to social tensionbetween females (Ashbury et al., 2015).Additionally, the hydroelectric dam and its associatedinfrastructure will separate the Sibual-buali Reserve from thewest block and will also impact the options for reconnectingthe east and west block. Over 20 km of road and 14 km ofelectricity transmission lines through Tapanuli orangutanhabitat are planned, and at least 3 million m3 of excavatedspoil is planned to be dumped in orangutan habitat(Comanditaire Venotschap (CV) Global Inter System, 2014,2016). Furthermore, it is well-established that infrastructuredevelopment, especially roads, can facilitate human accessinto previously inaccessible areas, eventually leading toadditional and often unrestricted levels of habitat degrada-tion and loss, hunting, and/or human-animal conflict(Laurance, 2015; Laurance & Arrea, 2017; van der Ree,Smith, & Grilo, 2015).Taken together, the hydroelectric project will drive theSibual-buali and Sitandiang corridor population (30 individ-uals, 95% CI [8–65]) and east block population (162 individ-uals) to a status of nonviable, which is defined here as apopulation with 0% probability of extinction and >90%retention of genetic diversity for a minimum of 1,000 years(Singleton et al., 2004; Marshall et al., 2009). Following theresults of the 2004 orangutan Population and Habitat Viabil-ity Assessment (PHVA) workshop, a population of >500individuals is considered viable using this definition (Single-ton et al., 2004). This will leave the west block as the lastremaining viable Tapanuli orangutan population. But giventhe current and projected threats of habitat degradation andloss, hunting, human-orangutan conflict, an expandinggoldmine, and a neutralized logging concession in the area(GoNSP, 2017; MoEF, 2017; MoF, 2014), this is anextremely risky scenario and should therefore be avoided atall costs, because these threats could drive this population tononviable status within as few as 1–2 generations.In conclusion, the Tapanuli orangutan was the latestextant great ape to be discovered, but given its extremelysmall population numbers and current and projected threats,it might well be the first one to go extinct. This would con-travene the Indonesian Law Regarding the Conservation ofBiological Resources and Ecosystems (Law No. 5/1990), aswell as the Aichi targets to which the Indonesian govern-ment has committed (Darajati et al., 2016; PoRI, 1990). Assuch, it is imperative that the Government of Indonesia takessome bold steps to secure its future, of which the mostimportant short-term ones are: (a) to halt the hydroelectricdam development; (b) change the land use status of theunprotected 15% of the area where the Tapanuli orangutanoccurs to a protected status; and (c) establish a corridorbetween the west and east block and improve the corridorbetween the west block and Sibual-buali Reserve. In addi-tion, the ongoing hunting and small-scale deforestation needto be halted through serious enforcement of Indonesia's reg-ulations concerning protected species.CONFLICT OF INTERESTThe authors declare no potential conflict of interest.AUTHOR CONTRIBUTIONSS.A.W., G.F., G.U., and M.G.N. conceived the paper,S.A.W., G.U., M.G.N., and H.S.K. conducted the analyses,S.A.W., G.F., G.U., H.S.K., and M.G.N. wrote the paper.No ethics approval was needed for this study. All data areavailable on request from the authors.ORCIDSerge A. Wich https://orcid.org/0000-0003-3954-5174REFERENCESAshbury, A. M., Posa, M. R. C., Dunkel, L. P., Spillmann, B.,Atmoko, S. S. U., van Schaik, C. P., & van Noordwijk, M. A.(2015). Why do orangutans leave the trees? Terrestrial behavioramong wild Bornean orangutans (Pongo pygmaeus wurmbii) atTuanan, Central Kalimantan. American Journal of Primatology, 77,1216–1229.Comanditaire Venotschap (CV) Global Inter System. (2014). ANDAL:Rencana Pembangunan Pembangkit Listrik Tenaga Air (PLTA)Batangtoru Kapasitas 500 MW Dan Jaringan Transmisi 275 KVDari PLTA Batang toru Sampai Desa Parsalakan Kec. AngkolaBarat Kab. Tapanuli Selatan Prov. Sumatera Utara. Medan,Republic of Indonesia: Perseroan Terbatas (PT) North SumateraHydro Energy.Comanditaire Venotschap (CV) Global Inter System. (2016). AdendumANDAL, RKL-RPL: Rencana Kegiatan Pembangunan PembangkitListrik Tenaga Air (PLTA) Batang Toru Dari Kapasitas 500 MWMenjadi 510 MW (4 x 127.5 MW) Dan Perubahan Lokasi QuarryDi Kabupaten Tapanuli Selatan - Provinsi Sumatera Utara.WICH ET AL. 3 of 4Medan, Republic of Indonesia: Perseroan Terbatas (PT) NorthSumatera Hydro Energy.Darajati, W., Pratiwi, S., Herwinda, E., Radiansyah, A. D., Nalang, V.S., Nooryanto, B., … Hakim, F. (2016). Indonesian biodiversitystrategy and action plan (IBSAP) 2015-2020. Jakarta, Republic ofIndonesia: Ministry of National Development Planning / NationalDevelopment Planning Agency of the Republic of Indonesia.GoNSP. (2017). Peraturan Daerah Provinsi Sumatera Utara, Nomor 2Tahun 2017, Tentang rencana tata ruang wilayah Provinsi Sum-atera Utara tahun 2017-2037. Medan, Republic of Indonesia: Gov-ernor of North Sumatra Province of the Republic of Indonesia.Laurance, W. F. (2015). Bad roads, good roads. In R. van der Ree, D.J. Smith, & C. Grilo (Eds.), Handbook of road ecology (pp. 10–15).New York, NY: John Wiley & Sons.Laurance, W. F., & Arrea, I. B. (2017). Roads to riches or ruin? Sci-ence, 358(6362), 442–444.Marshall, A. J., Lacy, R., Ancrenaz, M., Onnie, B., Husson, S. J.,Leighton, M., … Wich, S. A. (2009). Orangutan population biol-ogy, life history, and conservation. In S. A. Wich, S. S. UtamiAtmoko, T. Mitra Setia, & C. P. van Schaik (Eds.), Orangutans:Geographic variation in behavioral ecology and conservation(pp. 311–326). New York, NY: Oxford University Press.MoEF. (2017). Surat Keputusan Menteri Lingkungan Hidup danKehutanan Republik Indonesia, Nomor: SK.1076/MENLHK-PKTL/KUH/PLA.2/3/2017, Tentang Peta Perkembangan Pen-gukuhan Kawasan Hutan Provinsi Sumatera Utara Sampai Den-gan Tahun 2016. Jakarta, Republic of Indonesia: Ministry ofEnvironment and Forestry of the Republic of Indonesia.MoF. (2014). Surat Keputusan Menteri Kehutanan Republik Indonesia,Nomor: SK.579/MENHUT-II/2014, Tentang Kawasan Hutan Pro-vinsi Sumatera Utara. Jakarta, Republic of Indonesia: Ministry ofForestry of the Republic of Indonesia.Nater, A., Mattle-Greminger, M. P., Nurcahyo, A., Nowak, M. G., DeManuel, M., Desai, T., … Krützen, M. (2017). Morphometric,behavioral, and genomic evidence for a new orangutan species.Current Biology, 27(22), 3487–3498, e3410.Nowak, M. G., Rienzi, P., Wich, S. A., Meijaard, E., & Fredriksson, G.(2017). The IUCN red list of threatened species 2017.Pongo tapanuliensis. https://doi.org/10.2305/IUCN.UK.2017-3.RLTS.T120588639A120588662.enPoRI. (1990). Undang-Undang Republik Indonesia, Nomor 5 Tahun 1990,Tentang Konservasi Sumber Daya Alam Hayati Dan Ekosistemya.Jakarta, Republic of Indonesia: President of the Republic of Indonesia.Singleton, I., Wich, S., Husson, S., Stephens, S., Utami Atmoko, S. S.,Leighton, M., … Byers, O. (2004). Orangutan population and hab-itat viability assessment: Final report. Apple Valley, MN: IUCN/-SSC Conservation Breeding Specialist Group.Sloan, S., Supriatna, J., Campbell, M. J., Alamgir, M., &Laurance, W. F. (2018). Newly discovered orangutan speciesrequires urgent habitat protection. Current Biology, 28, R650–R651.van der Ree, R., Smith, D. J., & Grilo, C. (2015). The ecological effects oflinear infrastructure and traffic: Challenges and opportunities of rapidglobal growth. In R. van der Ree, D. J. Smith, & C. Grilo (Eds.), Hand-book of road ecology (pp. 1–9). New York, NY: John Wiley & Sons.van Schaik, C. P. (2004). Among orangutans: Red apes and the rise ofhuman culture. Cambridge, MA: Harvard University Press.Wich, S. A., Fredriksson, G. M., Usher, G., Peters, H. H., Priatna, D.,Basalamah, F., … Kühl, H. (2012). Hunting of Sumatran orang-utans and its importance in determining distribution and density.Biological Conservation, 146, 163–169.Wich, S. A., Riswan, J., Jensom, J., Refisch, J., & Nellemann, C.(2011). Orangutans and the economics of sustainable forest man-agement in Sumatra. United Nations Environment Programme(UNEP). Birkeland, Norway: Birkeland Trykkeri AS.Wich, S. A., Singleton, I., Nowak, M. G., Utami Atmoko, S. S.,Nisam, G., Arif, M. S., … Kühl, H. S. (2016). Land-cover changespredict steep declines for the Sumatran orangutan (Pongo abelii).Science Advances, 2, e1500789.Wich, S. A., Singleton, I., Utami-Atmoko, S. S., Geurts, M. L.,Rijksen, H. D., & van Schaik, C. P. (2003). The status of the Suma-tran orang-utan Pongo abelii: An update. Oryx, 37, 49–54.How to cite this article: Wich SA, Fredriksson G,Usher G, Kühl HS, Nowak MG. The Tapanuliorangutan: Status, threats, and steps for improvedconservation. Conservation Science and Practice.2019;1:e33. https://doi.org/10.1111/csp2.334 of 4 WICH ET AL.

Wich, SA

Fredriksson, G

Usher, G

Kühl, HS

Nowak, MG

LJMU Research Online (Liverpool John Moores University)

 Wich, SA, Fredriksson, G, Usher, G, Kühl, HS and Nowak, MG The Tapanuli orangutan: Status, threats, and steps for improved conservationhttp://researchonline.ljmu.ac.uk/10572/ArticleLJMU has developed LJMU Research Online for users to access the research output of the University more effectively. Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Users may download and/or print one copy of any article(s) in LJMU Research Online to facilitate their private study or for non-commercial research. You may not engage in further distribution of the material or use it for any profit-making activities or any commercial gain.The version presented here may differ from the published version or from the version of the record. Please see the repository URL above for details on accessing the published version and note that access may require a subscription. For more information please contact researchonline@ljmu.ac.ukhttp://researchonline.ljmu.ac.uk/Citation (please note it is advisable to refer to the publisher’s version if you intend to cite from this work) Wich, SA, Fredriksson, G, Usher, G, Kühl, HS and Nowak, MG (2019) The Tapanuli orangutan: Status, threats, and steps for improved conservation. Conservation Science and Practice. ISSN 2578-4854 LJMU Research OnlineP E R S P E C T I V E S A ND NOT E SThe Tapanuli orangutan: Status, threats, and steps for improvedconservationSerge A. Wich1,2 | Gabriella Fredriksson3 | Graham Usher3 | Hjalmar S. Kühl4,5 |Matthew G. Nowak3,61School of Natural Sciences and Psychology, Liverpool John MooresUniversity, Liverpool, UK2Institute for Biodiversity and Ecosystem Dynamics, University ofAmsterdam, Amsterdam, the Netherlands3Conservation Division, The PanEco Foundation - Sumatran OrangutanConservation Programme, Berg am Irchel, Switzerland4Department of Primatology, Max Planck Institute for EvolutionaryAnthropology, Leipzig, Germany5Sustainability and Complexity in Ape Habitat Group, German Centre forIntegrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig,Germany6Department of Anthropology, Southern Illinois University, Carbondale,IllinoisCorrespondenceSerge A. Wich, School of Natural Sciences and Psychology, James Parsons Building, Byrom street, L33AF, Liverpool, UK.Email: s.a.wich@ljmu.ac.ukKEYWORD S : Batang Toru, hydrodam, Tapanuli orangutanEver since the Tapanuli orangutan (Pongo tapanuliensis)was described two years ago (Nater et al., 2017) it has fre-quently been in the news for two primary reasons. First,because of the excitement generated by the discovery of thefirst new extant great ape species since 1929. Second,because of the immediate threat posed to the new species bythe development of a hydrodam to generate electricity(Sloan, Supriatna, Campbell, Alamgir, & Laurance, 2018).As the species has only been described recently there is nopaper that summarizes its status and threats even thoughsome of that information is available from a previous studywhere this species was still considered a population of theSumatran orangutan (Pongo abelii) (Wich et al., 2016). Inthis letter, we aim to remedy this gap by providing a succinctoverview of the status of and threats to the Tapanuli orangu-tan, as well as by identifying key steps toward improvedconservation. This is particularly relevant as there is a needto be able to determine the impact of the hydroelectric damdevelopment which is best achieved from a clear baseline.As with the other two orangutan species, the Tapanuliorangutan is considered to be Critically Endangered by theInternational Union for Conservation of Nature (IUCN)(Nowak, Rianti, Wich, Meijaard, & Fredriksson, 2017). Thespecies is only found in the forests of the Batang Toru Eco-system in the province of North Sumatra, Indonesia(Figure 1). Based on extensive survey work from 2000 to2012 it has been determined that the total extent of its distri-bution covers 1,023 km2 (Wich et al., 2016). It is found inthree main forest blocks with a total of 767 individuals (95%confidence intervals [CI] [231–1,597]): the west blockwhich houses 581 individuals (95%CI [180–1,201] [sum of533, 42, and 6 in Figure 1]), the east block with 162 individ-uals (95% CI [46–341]), and the Sibual-buali Reserve with24 individuals (95% CI [6–53], based on (Wich et al., 2016),with possibly small populations to the north and/or in theLubuk Raya Reserve). Of this distribution, roughly 85% isunder some form of protection status, but 15% is land forother uses (Nowak et al., 2017). The west block and theReceived: 8 February 2019 Accepted: 27 March 2019DOI: 10.1111/csp2.33This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the originalwork is properly cited.© 2019 The Authors. Conservation Science and Practice published by Wiley Periodicals, Inc. on behalf of Society for Conservation BiologyConservation Science and Practice. 2019;e33. wileyonlinelibrary.com/journal/csp2 1 of 4https://doi.org/10.1111/csp2.33Sibual-buali Reserve are still moderately connected andorangutan dispersal is expected to occur between those areasbased on the locations where nests have been found duringsurveys (Figure 1). It is less clear if orangutans can stillmove between the west and east block because of the pro-vincial road from Tarutung to Padangsidempuan separatingthese blocks as well as the Batang Toru River.There are several threats to the Tapanuli orangutan.Between 1985 and 2007, 43.3% of the forests in the provinceof North Sumatra (where the Tapanuli orangutan occurs)have been lost (Wich, Riswan, Jenson, Refisch, &Nellemann, 2011). Annual deforestation rates were particu-larly high from 1985 to 1990 (4.2%), decreased from 1990to 2000 (1.2%), and then increased again from 2000 to2008/2009 (2.3%). Particularly recent losses of peat swampareas on the coast where the species had been found in thepast (Wich et al., 2003) have led to a reduction of forest forthe Tapanuli orangutan as well as the slower but steady for-est loss that occurs around all three blocks. During1990-2009, annual forest loss for the area in which theTapanuli orangutan occurs was calculated as 0.11%, with arange of <0.01–0.84% (Wich et al., 2011). This is lowerthan the overall annual forest loss for North Sumatra due tothe Tapanuli orangutan occurring in more mountainous areaswhich have lower deforestation rates than areas at lower ele-vations. The other main threat is killing of orangutans. Thisoccurs in two circumstances. First, orangutan hunting stilloccurs in the area (Wich et al., 2012). Even though huntersdo not seem to go into the forest to specifically hunt fororangutans, they do opportunistically hunt/kill them for foodwhen encountered (Wich et al., 2012). Second, orangutansthat venture into community plantations have been killed asa result of human-orangutan conflict (Nater et al., 2017). Asorangutans are long-lived and have slow reproductive rates,even low levels of extrinsic mortality (i.e., >1% per year,which in this case is just a few individuals) represent a majorthreat to the long-term growth, stability, and persistence ofthe small-sized Tapanuli orangutan populations (Marshall etal., 2009).In addition to these threats there is a hydroelectric damwith associated infrastructure planned in the area (Sloanet al., 2018). The area of influence of the dam is planned inan area with the highest Tapanuli orangutan densities andcovers 5.5% (42 individuals, 95%CI [14–84]) of the totalFIGURE 1 Map showing the distribution of the Tapanuli orangutans, their population numbers and threats. The 95% confidence intervals (CI)for the various areas are: West block: 164–105, East block: 46–341, Hydro AoI: 14–84, Corridor: 2–12, Sibual-buali: 6–532 of 4 WICH ET AL.Tapanuli orangutan population (Wich et al., 2016). Orangu-tans in this area and surroundings will be negatively impactedthrough habitat degradation and loss. This is of particular con-cern for orangutan females because they are philopatric andtend not to move when they lose parts of their home range(van Schaik, 2004) and risk starvation or being killed whenthis occurs. Such home range loss and subsequent dispersalcan also lead to compression of orangutans in adjacent areasand inflated densities past the carrying capacity and hencelead to food shortages and future reductions in density(Husson, personal communication, January 15, 2019). If partsof their home range are lost, orangutans in disturbed areas willhave to use the remaining parts of their own home range moreintensively than before, which can also lead to social tensionbetween females (Ashbury et al., 2015).Additionally, the hydroelectric dam and its associatedinfrastructure will separate the Sibual-buali Reserve from thewest block and will also impact the options for reconnectingthe east and west block. Over 20 km of road and 14 km ofelectricity transmission lines through Tapanuli orangutanhabitat are planned, and at least 3 million m3 of excavatedspoil is planned to be dumped in orangutan habitat(Comanditaire Venotschap (CV) Global Inter System, 2014,2016). Furthermore, it is well-established that infrastructuredevelopment, especially roads, can facilitate human accessinto previously inaccessible areas, eventually leading toadditional and often unrestricted levels of habitat degrada-tion and loss, hunting, and/or human-animal conflict(Laurance, 2015; Laurance & Arrea, 2017; van der Ree,Smith, & Grilo, 2015).Taken together, the hydroelectric project will drive theSibual-buali and Sitandiang corridor population (30 individ-uals, 95% CI [8–65]) and east block population (162 individ-uals) to a status of nonviable, which is defined here as apopulation with 0% probability of extinction and >90%retention of genetic diversity for a minimum of 1,000 years(Singleton et al., 2004; Marshall et al., 2009). Following theresults of the 2004 orangutan Population and Habitat Viabil-ity Assessment (PHVA) workshop, a population of >500individuals is considered viable using this definition (Single-ton et al., 2004). This will leave the west block as the lastremaining viable Tapanuli orangutan population. But giventhe current and projected threats of habitat degradation andloss, hunting, human-orangutan conflict, an expandinggoldmine, and a neutralized logging concession in the area(GoNSP, 2017; MoEF, 2017; MoF, 2014), this is anextremely risky scenario and should therefore be avoided atall costs, because these threats could drive this population tononviable status within as few as 1–2 generations.In conclusion, the Tapanuli orangutan was the latestextant great ape to be discovered, but given its extremelysmall population numbers and current and projected threats,it might well be the first one to go extinct. This would con-travene the Indonesian Law Regarding the Conservation ofBiological Resources and Ecosystems (Law No. 5/1990), aswell as the Aichi targets to which the Indonesian govern-ment has committed (Darajati et al., 2016; PoRI, 1990). Assuch, it is imperative that the Government of Indonesia takessome bold steps to secure its future, of which the mostimportant short-term ones are: (a) to halt the hydroelectricdam development; (b) change the land use status of theunprotected 15% of the area where the Tapanuli orangutanoccurs to a protected status; and (c) establish a corridorbetween the west and east block and improve the corridorbetween the west block and Sibual-buali Reserve. In addi-tion, the ongoing hunting and small-scale deforestation needto be halted through serious enforcement of Indonesia's reg-ulations concerning protected species.CONFLICT OF INTERESTThe authors declare no potential conflict of interest.AUTHOR CONTRIBUTIONSS.A.W., G.F., G.U., and M.G.N. conceived the paper,S.A.W., G.U., M.G.N., and H.S.K. conducted the analyses,S.A.W., G.F., G.U., H.S.K., and M.G.N. wrote the paper.No ethics approval was needed for this study. All data areavailable on request from the authors.ORCIDSerge A. Wich https://orcid.org/0000-0003-3954-5174REFERENCESAshbury, A. M., Posa, M. R. C., Dunkel, L. P., Spillmann, B.,Atmoko, S. S. U., van Schaik, C. P., & van Noordwijk, M. A.(2015). Why do orangutans leave the trees? Terrestrial behavioramong wild Bornean orangutans (Pongo pygmaeus wurmbii) atTuanan, Central Kalimantan. American Journal of Primatology, 77,1216–1229.Comanditaire Venotschap (CV) Global Inter System. (2014). ANDAL:Rencana Pembangunan Pembangkit Listrik Tenaga Air (PLTA)Batangtoru Kapasitas 500 MW Dan Jaringan Transmisi 275 KVDari PLTA Batang toru Sampai Desa Parsalakan Kec. AngkolaBarat Kab. Tapanuli Selatan Prov. Sumatera Utara. Medan,Republic of Indonesia: Perseroan Terbatas (PT) North SumateraHydro Energy.Comanditaire Venotschap (CV) Global Inter System. (2016). AdendumANDAL, RKL-RPL: Rencana Kegiatan Pembangunan PembangkitListrik Tenaga Air (PLTA) Batang Toru Dari Kapasitas 500 MWMenjadi 510 MW (4 x 127.5 MW) Dan Perubahan Lokasi QuarryDi Kabupaten Tapanuli Selatan - Provinsi Sumatera Utara.WICH ET AL. 3 of 4Medan, Republic of Indonesia: Perseroan Terbatas (PT) NorthSumatera Hydro Energy.Darajati, W., Pratiwi, S., Herwinda, E., Radiansyah, A. D., Nalang, V.S., Nooryanto, B., … Hakim, F. (2016). Indonesian biodiversitystrategy and action plan (IBSAP) 2015-2020. Jakarta, Republic ofIndonesia: Ministry of National Development Planning / NationalDevelopment Planning Agency of the Republic of Indonesia.GoNSP. (2017). Peraturan Daerah Provinsi Sumatera Utara, Nomor 2Tahun 2017, Tentang rencana tata ruang wilayah Provinsi Sum-atera Utara tahun 2017-2037. Medan, Republic of Indonesia: Gov-ernor of North Sumatra Province of the Republic of Indonesia.Laurance, W. F. (2015). Bad roads, good roads. In R. van der Ree, D.J. Smith, & C. Grilo (Eds.), Handbook of road ecology (pp. 10–15).New York, NY: John Wiley & Sons.Laurance, W. F., & Arrea, I. B. (2017). Roads to riches or ruin? Sci-ence, 358(6362), 442–444.Marshall, A. J., Lacy, R., Ancrenaz, M., Onnie, B., Husson, S. J.,Leighton, M., … Wich, S. A. (2009). Orangutan population biol-ogy, life history, and conservation. In S. A. Wich, S. S. UtamiAtmoko, T. Mitra Setia, & C. P. van Schaik (Eds.), Orangutans:Geographic variation in behavioral ecology and conservation(pp. 311–326). New York, NY: Oxford University Press.MoEF. (2017). Surat Keputusan Menteri Lingkungan Hidup danKehutanan Republik Indonesia, Nomor: SK.1076/MENLHK-PKTL/KUH/PLA.2/3/2017, Tentang Peta Perkembangan Pen-gukuhan Kawasan Hutan Provinsi Sumatera Utara Sampai Den-gan Tahun 2016. Jakarta, Republic of Indonesia: Ministry ofEnvironment and Forestry of the Republic of Indonesia.MoF. (2014). Surat Keputusan Menteri Kehutanan Republik Indonesia,Nomor: SK.579/MENHUT-II/2014, Tentang Kawasan Hutan Pro-vinsi Sumatera Utara. Jakarta, Republic of Indonesia: Ministry ofForestry of the Republic of Indonesia.Nater, A., Mattle-Greminger, M. P., Nurcahyo, A., Nowak, M. G., DeManuel, M., Desai, T., … Krützen, M. (2017). Morphometric,behavioral, and genomic evidence for a new orangutan species.Current Biology, 27(22), 3487–3498, e3410.Nowak, M. G., Rienzi, P., Wich, S. A., Meijaard, E., & Fredriksson, G.(2017). The IUCN red list of threatened species 2017.Pongo tapanuliensis. https://doi.org/10.2305/IUCN.UK.2017-3.RLTS.T120588639A120588662.enPoRI. (1990). Undang-Undang Republik Indonesia, Nomor 5 Tahun 1990,Tentang Konservasi Sumber Daya Alam Hayati Dan Ekosistemya.Jakarta, Republic of Indonesia: President of the Republic of Indonesia.Singleton, I., Wich, S., Husson, S., Stephens, S., Utami Atmoko, S. S.,Leighton, M.,… Byers, O. (2004). Orangutan population and hab-itat viability assessment: Final report. Apple Valley, MN: IUCN/-SSC Conservation Breeding Specialist Group.Sloan, S., Supriatna, J., Campbell, M. J., Alamgir, M., &Laurance, W. F. (2018). Newly discovered orangutan speciesrequires urgent habitat protection. Current Biology, 28, R650–R651.van der Ree, R., Smith, D. J., & Grilo, C. (2015). The ecological effects oflinear infrastructure and traffic: Challenges and opportunities of rapidglobal growth. In R. van der Ree, D. J. Smith, & C. Grilo (Eds.), Hand-book of road ecology (pp. 1–9). New York, NY: John Wiley & Sons.van Schaik, C. P. (2004). Among orangutans: Red apes and the rise ofhuman culture. Cambridge, MA: Harvard University Press.Wich, S. A., Fredriksson, G. M., Usher, G., Peters, H. H., Priatna, D.,Basalamah, F., … Kühl, H. (2012). Hunting of Sumatran orang-utans and its importance in determining distribution and density.Biological Conservation, 146, 163–169.Wich, S. A., Riswan, J., Jensom, J., Refisch, J., & Nellemann, C.(2011). Orangutans and the economics of sustainable forest man-agement in Sumatra. United Nations Environment Programme(UNEP). Birkeland, Norway: Birkeland Trykkeri AS.Wich, S. A., Singleton, I., Nowak, M. G., Utami Atmoko, S. S.,Nisam, G., Arif, M. S.,… Kühl, H. S. (2016). Land-cover changespredict steep declines for the Sumatran orangutan (Pongo abelii).Science Advances, 2, e1500789.Wich, S. A., Singleton, I., Utami-Atmoko, S. S., Geurts, M. L.,Rijksen, H. D., & van Schaik, C. P. (2003). The status of the Suma-tran orang-utan Pongo abelii: An update. Oryx, 37, 49–54.How to cite this article: Wich SA, Fredriksson G,Usher G, Kühl HS, Nowak MG. The Tapanuliorangutan: Status, threats, and steps for improvedconservation. Conservation Science and Practice.2019;e33. https://doi.org/10.1111/csp2.334 of 4 WICH ET AL.

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UvA-DARE is a service provided by the library of the University of Amsterdam (https://dare.uva.nl)UvA-DARE (Digital Academic Repository)The Tapanuli orangutan: Status, threats, and steps for improved conservationWich, S.A.; Frederiksson, G.; Usher, G.; Kühl, H.S.; Nowak, M.G.DOI10.1111/csp2.33Publication date2019Document VersionFinal published versionPublished inConservation Science and PracticeLicenseCC BYLink to publicationCitation for published version (APA):Wich, S. A., Frederiksson, G., Usher, G., Kühl, H. S., & Nowak, M. G. (2019). The Tapanuliorangutan: Status, threats, and steps for improved conservation. Conservation Science andPractice, 1(6), Article e33. https://doi.org/10.1111/csp2.33General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s)and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an opencontent license (like Creative Commons).Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, pleaselet the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the materialinaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letterto: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. Youwill be contacted as soon as possible.Download date:24 Jan 2024P E R S P E C T I V E S A ND NOT E SThe Tapanuli orangutan: Status, threats, and steps for improvedconservationSerge A. Wich1,2 | Gabriella Fredriksson3 | Graham Usher3 | Hjalmar S. Kühl4,5 |Matthew G. Nowak3,61School of Natural Sciences and Psychology, Liverpool John MooresUniversity, Liverpool, UK2Institute for Biodiversity and Ecosystem Dynamics, University ofAmsterdam, Amsterdam, the Netherlands3Conservation Division, The PanEco Foundation - Sumatran OrangutanConservation Programme, Berg am Irchel, Switzerland4Department of Primatology, Max Planck Institute for EvolutionaryAnthropology, Leipzig, Germany5Sustainability and Complexity in Ape Habitat Group, German Centre forIntegrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig,Germany6Department of Anthropology, Southern Illinois University, Carbondale,IllinoisCorrespondenceSerge A. Wich, School of Natural Sciences and Psychology, James Parsons Building, Byrom street, L33AF, Liverpool, UK.Email: s.a.wich@ljmu.ac.ukKEYWORD S : Batang Toru, hydrodam, Tapanuli orangutanEver since the Tapanuli orangutan (Pongo tapanuliensis)was described two years ago (Nater et al., 2017) it has fre-quently been in the news for two primary reasons. First,because of the excitement generated by the discovery of thefirst new extant great ape species since 1929. Second,because of the immediate threat posed to the new species bythe development of a hydrodam to generate electricity(Sloan, Supriatna, Campbell, Alamgir, & Laurance, 2018).As the species has only been described recently there is nopaper that summarizes its status and threats even thoughsome of that information is available from a previous studywhere this species was still considered a population of theSumatran orangutan (Pongo abelii) (Wich et al., 2016). Inthis letter, we aim to remedy this gap by providing a succinctoverview of the status of and threats to the Tapanuli orangu-tan, as well as by identifying key steps toward improvedconservation. This is particularly relevant as there is a needto be able to determine the impact of the hydroelectric damdevelopment which is best achieved from a clear baseline.As with the other two orangutan species, the Tapanuliorangutan is considered to be Critically Endangered by theInternational Union for Conservation of Nature (IUCN)(Nowak, Rianti, Wich, Meijaard, & Fredriksson, 2017). Thespecies is only found in the forests of the Batang Toru Eco-system in the province of North Sumatra, Indonesia(Figure 1). Based on extensive survey work from 2000 to2012 it has been determined that the total extent of its distri-bution covers 1,023 km2 (Wich et al., 2016). It is found inthree main forest blocks with a total of 767 individuals (95%confidence intervals [CI] [231–1,597]): the west blockwhich houses 581 individuals (95%CI [180–1,201] [sum of533, 42, and 6 in Figure 1]), the east block with 162 individ-uals (95% CI [46–341]), and the Sibual-buali Reserve with24 individuals (95% CI [6–53], based on (Wich et al., 2016),with possibly small populations to the north and/or in theLubuk Raya Reserve). Of this distribution, roughly 85% isunder some form of protection status, but 15% is land forother uses (Nowak et al., 2017). The west block and theReceived: 8 February 2019 Accepted: 27 March 2019DOI: 10.1111/csp2.33This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the originalwork is properly cited.© 2019 The Authors. Conservation Science and Practice published by Wiley Periodicals, Inc. on behalf of Society for Conservation BiologyConservation Science and Practice. 2019;1:e33. wileyonlinelibrary.com/journal/csp2 1 of 4https://doi.org/10.1111/csp2.33Sibual-buali Reserve are still moderately connected andorangutan dispersal is expected to occur between those areasbased on the locations where nests have been found duringsurveys (Figure 1). It is less clear if orangutans can stillmove between the west and east block because of the pro-vincial road from Tarutung to Padangsidempuan separatingthese blocks as well as the Batang Toru River.There are several threats to the Tapanuli orangutan.Between 1985 and 2007, 43.3% of the forests in the provinceof North Sumatra (where the Tapanuli orangutan occurs)have been lost (Wich, Riswan, Jenson, Refisch, &Nellemann, 2011). Annual deforestation rates were particu-larly high from 1985 to 1990 (4.2%), decreased from 1990to 2000 (1.2%), and then increased again from 2000 to2008/2009 (2.3%). Particularly recent losses of peat swampareas on the coast where the species had been found in thepast (Wich et al., 2003) have led to a reduction of forest forthe Tapanuli orangutan as well as the slower but steady for-est loss that occurs around all three blocks. During1990-2009, annual forest loss for the area in which theTapanuli orangutan occurs was calculated as 0.11%, with arange of <0.01–0.84% (Wich et al., 2011). This is lowerthan the overall annual forest loss for North Sumatra due tothe Tapanuli orangutan occurring in more mountainous areaswhich have lower deforestation rates than areas at lower ele-vations. The other main threat is killing of orangutans. Thisoccurs in two circumstances. First, orangutan hunting stilloccurs in the area (Wich et al., 2012). Even though huntersdo not seem to go into the forest to specifically hunt fororangutans, they do opportunistically hunt/kill them for foodwhen encountered (Wich et al., 2012). Second, orangutansthat venture into community plantations have been killed asa result of human-orangutan conflict (Nater et al., 2017). Asorangutans are long-lived and have slow reproductive rates,even low levels of extrinsic mortality (i.e., >1% per year,which in this case is just a few individuals) represent a majorthreat to the long-term growth, stability, and persistence ofthe small-sized Tapanuli orangutan populations (Marshall etal., 2009).In addition to these threats there is a hydroelectric damwith associated infrastructure planned in the area (Sloanet al., 2018). The area of influence of the dam is planned inan area with the highest Tapanuli orangutan densities andcovers 5.5% (42 individuals, 95%CI [14–84]) of the totalFIGURE 1 Map showing the distribution of the Tapanuli orangutans, their population numbers and threats. The 95% confidence intervals (CI)for the various areas are: West block: 164–105, East block: 46–341, Hydro AoI: 14–84, Corridor: 2–12, Sibual-buali: 6–532 of 4 WICH ET AL.Tapanuli orangutan population (Wich et al., 2016). Orangu-tans in this area and surroundings will be negatively impactedthrough habitat degradation and loss. This is of particular con-cern for orangutan females because they are philopatric andtend not to move when they lose parts of their home range(van Schaik, 2004) and risk starvation or being killed whenthis occurs. Such home range loss and subsequent dispersalcan also lead to compression of orangutans in adjacent areasand inflated densities past the carrying capacity and hencelead to food shortages and future reductions in density(Husson, personal communication, January 15, 2019). If partsof their home range are lost, orangutans in disturbed areas willhave to use the remaining parts of their own home range moreintensively than before, which can also lead to social tensionbetween females (Ashbury et al., 2015).Additionally, the hydroelectric dam and its associatedinfrastructure will separate the Sibual-buali Reserve from thewest block and will also impact the options for reconnectingthe east and west block. Over 20 km of road and 14 km ofelectricity transmission lines through Tapanuli orangutanhabitat are planned, and at least 3 million m3 of excavatedspoil is planned to be dumped in orangutan habitat(Comanditaire Venotschap (CV) Global Inter System, 2014,2016). Furthermore, it is well-established that infrastructuredevelopment, especially roads, can facilitate human accessinto previously inaccessible areas, eventually leading toadditional and often unrestricted levels of habitat degrada-tion and loss, hunting, and/or human-animal conflict(Laurance, 2015; Laurance & Arrea, 2017; van der Ree,Smith, & Grilo, 2015).Taken together, the hydroelectric project will drive theSibual-buali and Sitandiang corridor population (30 individ-uals, 95% CI [8–65]) and east block population (162 individ-uals) to a status of nonviable, which is defined here as apopulation with 0% probability of extinction and >90%retention of genetic diversity for a minimum of 1,000 years(Singleton et al., 2004; Marshall et al., 2009). Following theresults of the 2004 orangutan Population and Habitat Viabil-ity Assessment (PHVA) workshop, a population of >500individuals is considered viable using this definition (Single-ton et al., 2004). This will leave the west block as the lastremaining viable Tapanuli orangutan population. But giventhe current and projected threats of habitat degradation andloss, hunting, human-orangutan conflict, an expandinggoldmine, and a neutralized logging concession in the area(GoNSP, 2017; MoEF, 2017; MoF, 2014), this is anextremely risky scenario and should therefore be avoided atall costs, because these threats could drive this population tononviable status within as few as 1–2 generations.In conclusion, the Tapanuli orangutan was the latestextant great ape to be discovered, but given its extremelysmall population numbers and current and projected threats,it might well be the first one to go extinct. This would con-travene the Indonesian Law Regarding the Conservation ofBiological Resources and Ecosystems (Law No. 5/1990), aswell as the Aichi targets to which the Indonesian govern-ment has committed (Darajati et al., 2016; PoRI, 1990). Assuch, it is imperative that the Government of Indonesia takessome bold steps to secure its future, of which the mostimportant short-term ones are: (a) to halt the hydroelectricdam development; (b) change the land use status of theunprotected 15% of the area where the Tapanuli orangutanoccurs to a protected status; and (c) establish a corridorbetween the west and east block and improve the corridorbetween the west block and Sibual-buali Reserve. In addi-tion, the ongoing hunting and small-scale deforestation needto be halted through serious enforcement of Indonesia's reg-ulations concerning protected species.CONFLICT OF INTERESTThe authors declare no potential conflict of interest.AUTHOR CONTRIBUTIONSS.A.W., G.F., G.U., and M.G.N. conceived the paper,S.A.W., G.U., M.G.N., and H.S.K. conducted the analyses,S.A.W., G.F., G.U., H.S.K., and M.G.N. wrote the paper.No ethics approval was needed for this study. All data areavailable on request from the authors.ORCIDSerge A. Wich https://orcid.org/0000-0003-3954-5174REFERENCESAshbury, A. M., Posa, M. R. C., Dunkel, L. P., Spillmann, B.,Atmoko, S. S. U., van Schaik, C. P., & van Noordwijk, M. A.(2015). Why do orangutans leave the trees? Terrestrial behavioramong wild Bornean orangutans (Pongo pygmaeus wurmbii) atTuanan, Central Kalimantan. American Journal of Primatology, 77,1216–1229.Comanditaire Venotschap (CV) Global Inter System. (2014). ANDAL:Rencana Pembangunan Pembangkit Listrik Tenaga Air (PLTA)Batangtoru Kapasitas 500 MW Dan Jaringan Transmisi 275 KVDari PLTA Batang toru Sampai Desa Parsalakan Kec. AngkolaBarat Kab. Tapanuli Selatan Prov. Sumatera Utara. Medan,Republic of Indonesia: Perseroan Terbatas (PT) North SumateraHydro Energy.Comanditaire Venotschap (CV) Global Inter System. (2016). AdendumANDAL, RKL-RPL: Rencana Kegiatan Pembangunan PembangkitListrik Tenaga Air (PLTA) Batang Toru Dari Kapasitas 500 MWMenjadi 510 MW (4 x 127.5 MW) Dan Perubahan Lokasi QuarryDi Kabupaten Tapanuli Selatan - Provinsi Sumatera Utara.WICH ET AL. 3 of 4Medan, Republic of Indonesia: Perseroan Terbatas (PT) NorthSumatera Hydro Energy.Darajati, W., Pratiwi, S., Herwinda, E., Radiansyah, A. D., Nalang, V.S., Nooryanto, B., … Hakim, F. (2016). Indonesian biodiversitystrategy and action plan (IBSAP) 2015-2020. Jakarta, Republic ofIndonesia: Ministry of National Development Planning / NationalDevelopment Planning Agency of the Republic of Indonesia.GoNSP. (2017). Peraturan Daerah Provinsi Sumatera Utara, Nomor 2Tahun 2017, Tentang rencana tata ruang wilayah Provinsi Sum-atera Utara tahun 2017-2037. Medan, Republic of Indonesia: Gov-ernor of North Sumatra Province of the Republic of Indonesia.Laurance, W. F. (2015). Bad roads, good roads. In R. van der Ree, D.J. Smith, & C. Grilo (Eds.), Handbook of road ecology (pp. 10–15).New York, NY: John Wiley & Sons.Laurance, W. F., & Arrea, I. B. (2017). Roads to riches or ruin? Sci-ence, 358(6362), 442–444.Marshall, A. J., Lacy, R., Ancrenaz, M., Onnie, B., Husson, S. J.,Leighton, M., … Wich, S. A. (2009). Orangutan population biol-ogy, life history, and conservation. In S. A. Wich, S. S. UtamiAtmoko, T. Mitra Setia, & C. P. van Schaik (Eds.), Orangutans:Geographic variation in behavioral ecology and conservation(pp. 311–326). New York, NY: Oxford University Press.MoEF. (2017). Surat Keputusan Menteri Lingkungan Hidup danKehutanan Republik Indonesia, Nomor: SK.1076/MENLHK-PKTL/KUH/PLA.2/3/2017, Tentang Peta Perkembangan Pen-gukuhan Kawasan Hutan Provinsi Sumatera Utara Sampai Den-gan Tahun 2016. Jakarta, Republic of Indonesia: Ministry ofEnvironment and Forestry of the Republic of Indonesia.MoF. (2014). Surat Keputusan Menteri Kehutanan Republik Indonesia,Nomor: SK.579/MENHUT-II/2014, Tentang Kawasan Hutan Pro-vinsi Sumatera Utara. Jakarta, Republic of Indonesia: Ministry ofForestry of the Republic of Indonesia.Nater, A., Mattle-Greminger, M. P., Nurcahyo, A., Nowak, M. G., DeManuel, M., Desai, T., … Krützen, M. (2017). Morphometric,behavioral, and genomic evidence for a new orangutan species.Current Biology, 27(22), 3487–3498, e3410.Nowak, M. G., Rienzi, P., Wich, S. A., Meijaard, E., & Fredriksson, G.(2017). The IUCN red list of threatened species 2017.Pongo tapanuliensis. https://doi.org/10.2305/IUCN.UK.2017-3.RLTS.T120588639A120588662.enPoRI. (1990). Undang-Undang Republik Indonesia, Nomor 5 Tahun 1990,Tentang Konservasi Sumber Daya Alam Hayati Dan Ekosistemya.Jakarta, Republic of Indonesia: President of the Republic of Indonesia.Singleton, I., Wich, S., Husson, S., Stephens, S., Utami Atmoko, S. S.,Leighton, M., … Byers, O. (2004). Orangutan population and hab-itat viability assessment: Final report. Apple Valley, MN: IUCN/-SSC Conservation Breeding Specialist Group.Sloan, S., Supriatna, J., Campbell, M. J., Alamgir, M., &Laurance, W. F. (2018). Newly discovered orangutan speciesrequires urgent habitat protection. Current Biology, 28, R650–R651.van der Ree, R., Smith, D. J., & Grilo, C. (2015). The ecological effects oflinear infrastructure and traffic: Challenges and opportunities of rapidglobal growth. In R. van der Ree, D. J. Smith, & C. Grilo (Eds.), Hand-book of road ecology (pp. 1–9). New York, NY: John Wiley & Sons.van Schaik, C. P. (2004). Among orangutans: Red apes and the rise ofhuman culture. Cambridge, MA: Harvard University Press.Wich, S. A., Fredriksson, G. M., Usher, G., Peters, H. H., Priatna, D.,Basalamah, F., … Kühl, H. (2012). Hunting of Sumatran orang-utans and its importance in determining distribution and density.Biological Conservation, 146, 163–169.Wich, S. A., Riswan, J., Jensom, J., Refisch, J., & Nellemann, C.(2011). Orangutans and the economics of sustainable forest man-agement in Sumatra. United Nations Environment Programme(UNEP). Birkeland, Norway: Birkeland Trykkeri AS.Wich, S. A., Singleton, I., Nowak, M. G., Utami Atmoko, S. S.,Nisam, G., Arif, M. S., … Kühl, H. S. (2016). Land-cover changespredict steep declines for the Sumatran orangutan (Pongo abelii).Science Advances, 2, e1500789.Wich, S. A., Singleton, I., Utami-Atmoko, S. S., Geurts, M. L.,Rijksen, H. D., & van Schaik, C. P. (2003). The status of the Suma-tran orang-utan Pongo abelii: An update. Oryx, 37, 49–54.How to cite this article: Wich SA, Fredriksson G,Usher G, Kühl HS, Nowak MG. The Tapanuliorangutan: Status, threats, and steps for improvedconservation. Conservation Science and Practice.2019;1:e33. https://doi.org/10.1111/csp2.334 of 4 WICH ET AL.

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