Humanitarian workers found the body on Dec. 3, a week after cyclone-driven storms triggered destructive floods and landslides across Sumatra, according to Panut Hadisiswoyo, founder of the Orangutan Information Centre (OIC). The carcass reportedly<\/a> had the flesh torn from its face and that its condition was consistent with having been swept away by the cascading debris.<\/p>\n \u201cIt shows that the habitat has been impacted, and likely some individuals were swept away by landslides or floods. That is entirely possible,\u201d Panut told Mongabay.<\/p>\n He said the landslide struck the western side of the Batang Toru ecosystem, a biodiversity stronghold that hosts one of three known Tapanuli orangutan (Pongo tapanuliensis) populations, as well as other vanishingly rare species such as the Sumatran tiger (Panthera tigris sumatrae) and Malayan tapir (Tapirus indicus).<\/p>\n \u201cWith the size of the western block being around 50,000-60,000 hectares [about 124,000-148,000 acres], it is very plausible that parts of the habitat collapsed, dragging orangutans along with it,\u201d Panut said.<\/p>\n A spatial analysis by Erik Meijaard, managing director of Borneo Futures and one of the scientists who first described the Tapanuli orangutan as a new-to-science species, estimates that 4,800-7,200 hectares (11,900-17,800 acres) of forest on the mountain slopes in the western block \u2014 home to roughly 35 orangutans \u2014 appear to have been destroyed by the landslides. Remote-sensing expert David Gaveau, founder of conservation tech startup TheTreeMap, said he was stunned by the before-and-after satellite images.<\/p>\n \u201cI have never seen anything like this before during my 20 years of monitoring deforestation in Indonesia with satellites,\u201d he told AFP<\/a>.<\/p>\n When the Tapanuli orangutan was first described by scientists in 2017, it was already the world\u2019s most threatened great ape. With its frizzy cinnamon hair and wide face, the Tapanuli represents the oldest surviving orangutan lineage \u2014 descendants of the first ancestral apes that arrived in Sumatra more than 3 million years ago.<\/p>\n Over the last three generations, its population has fallen by an estimated 83%, driven by human-wildlife conflict, hunting, and habitat loss from agriculture and industrial projects, including a gold mine and a proposed hydropower dam. Today, only about 577-760 individuals remain in a patchwork of shrinking forest fragments in Indonesia\u2019s North Sumatra province.<\/p>\n The potential death of all 35 individuals living along the landslide-hit western slopes would represent more than 4% of the total population \u2014 \u201ca major blow,\u201d Meijaard said.<\/p>\n Even small losses carry heavy consequences. Removing just 1% of the population a year would ultimately end in extinction, because orangutans only reproduce every six to nine years, Panut said.<\/p>\n Beyond the confirmed fatality, conservationists are increasingly worried about other Tapanuli orangutans whose home ranges lie near the disaster zone.<\/p>\n None of the 10 individual orangutans that OIC routinely monitors in the forest corridor linking the Sibualbuali nature reserve with the western Batang Toru block have been seen since the disaster.<\/p>\n \u201cAfter the recent severe flood, what we noticed is this: we used to see orangutans next to the riverbank, we could also see siamangs, gibbons, civets or hornbills,\u201d said OIC ranger Amran Siagian, as quoted by Reuters<\/a>. \u201cNow, after the disaster, whenever we walk, we don\u2019t see them anymore.\u201d<\/p>\n Panut said he hopes the animals have moved out of the affected area. Serge Wich, a professor of primate biology at Liverpool John Moores University in the U.K. and another of the scientists who first described the species, noted that orangutans often respond to heavy rain by sheltering in trees until the storm passes. The orangutan is not the only wildlife casualty of the recent flooding and landslides.<\/p>\n Last week, images of a dead Sumatran elephant (Elephas maximus sumatranus) swept away by floods in Aceh province also went viral \u2014 another reminder that the island\u2019s threatened species are exposed to escalating climate-driven disasters.<\/p>\n As of Dec. 12, the orangutan carcass remains where it was found, Panut said.<\/p>\n \u201cWe haven\u2019t been able to go there for retrieval yet. Ideally, the remains should be recovered because the Tapanuli orangutan is a protected species, and the carcass has scientific value for further study. Hair samples, bones, the skull \u2014 all of that could be useful,\u201d he said. Panut said the orangutan\u2019s death should serve as a warning to the government to safeguard the Batang Toru ecosystem, which is under pressure from industrial development, including a hydropower plant and a gold mine.<\/p>\n Both operations have been temporarily halted by the environment ministry pending post-disaster reviews, with officials saying they had \u201ccontributed significantly to the pressure on the environment.\u201d<\/p>\n Panut said the temporary suspension falls far short of what\u2019s needed.<\/p>\n The government, he said, must designate Batang Toru as a strategic landscape under the national zoning plan to block future industrial activity that threatens both the orangutans and local human communities.<\/p>\n The storms that caused the landslides also killed nearly 1,000 people across Sumatra, underscoring the scale of the tragedy.<\/p>\n \u201cWith this disaster, the survival of both the species and the people in three districts requires national intervention,\u201d Panut said. \u201cIf the government doesn\u2019t take this seriously, disasters will continue to take lives, displace communities, and cause massive losses.\u201d<\/p>\n \u00a0<\/p>\n Banner image: A mother and infant Tapanuli orangutan were directly sighted in the Lumut Maju peat swamp forest in North Sumatra. Image by Junaidi Hanafiah\/Mongabay-Indonesia.<\/p>\n \u00a0<\/p>\n FEEDBACK: Use\u00a0this form<\/a>\u00a0to send a message to the author of this post. If you want to post a public comment, you can do that at the bottom of the page.<\/p>\n ![\"Flood](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/12\/AP25336560227612-1-768x512.jpg\")
Flood survivors use logs to cross a river in Batang Toru, North Sumatra, Indonesia, on Dec. 2, 2025. Image by AP Photo\/Binsar Bakkara.<\/p>\n
Based on the scale of visible damage, \u201cit wouldn\u2019t surprise us if they are all dead,\u201d Meijaard told the BBC<\/a>.<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/12\/unnamed-2.png\")
<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/12\/unnamed-1.png\")
Satellite imagery of the Batang Toru area from Planet reveals the loss of forest cover between November 5 (top) and December 5 (bottom). Image courtesy of Mighty Earth.
\nMajor blow<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/12\/Orangutan_Tapanuli-768x512.jpg\")
Two Tapanuli orangutans in Batang Toru forest, North Sumatra, Indonesia, in September 2018. Image courtesy of Prayugo Utomo\/Wikimedia Commons.
\nWhere are the apes?<\/p>\n
\u201cWe haven\u2019t seen the individuals we regularly track. They may have moved to safer places, especially if their feeding areas were hit by landslides. They may have migrated elsewhere \u2014 that is entirely possible,\u201d he said.
But their prolonged absence raises concern.<\/p>\n
\u201cBut this time, by the time the rain stopped it was too late: parts of their habitat \u2014 the slopes of valleys \u2014 were wiped out by landslides, which means there must have been consequences for them,\u201d he said<\/a>.<\/p>\n
Retrieving the body would also help determine the exact cause of death, he added.<\/p>\n![\"Men](\"https:\/\/www.newsbeep.com\/il\/wp-content\/uploads\/2025\/12\/flash-flood-in-Batang-Toru-768x512.jpg\")
Men stand on logs swept away by flash flood in Batang Toru, North Sumatra, Dec. 2. Image by AP Photo\/Binsar Bakkara.
\nWake-up call<\/p>\n <\/p>\n