Even powerful orangutans are helpless when the forest comes down
In the aftermath of Cyclone Senyar's devastation across Southeast Asia in November 2025, the world's rarest great ape absorbed a blow that numbers alone struggle to convey: roughly 58 Tapanuli orangutans — nearly one in fourteen of the species' entire remaining population — were killed in four days of rain and landslides on the island of Sumatra. The species, unknown to science until 2017 and confined to a single forest in North Sumatra, had already been worn thin by habitat loss and human pressure; now climate change has introduced a crueler arithmetic, one that can erase years of conservation effort in a single storm. What the cyclone leaves behind is not merely grief but a question humanity has not yet answered: how do we protect the irreplaceable from a future growing less predictable by the season.
- A single cyclone erased roughly 7% of an entire species in four days — a loss so concentrated it strains the boundary between disaster and extinction event.
- A humanitarian worker wading through mud and human bodies in Pulo Pakkat village found an orangutan half-buried in debris, its face stripped bare by the force of the landslide — the storm's violence made viscerally legible.
- Conservationists noticed the warning signs weeks later, when orangutan sightings across the region had nearly ceased, prompting a study that revised initial death estimates upward from 35 to 58 — and counting.
- The published toll is acknowledged as conservative, excluding the cascading losses of destroyed forest canopy, depleted food sources, and the genetic and behavioral knowledge buried with each animal.
- With fewer than 800 Tapanuli orangutans remaining and extreme weather events intensifying, scientists warn that critically endangered species now face not only slow erosion but the sudden, total collapse that a single bad season can deliver.
In late November 2025, Cyclone Senyar swept across Sumatra with enough force to kill more than a thousand people across Southeast Asia — the region's deadliest natural disaster of the year. What it did to the wildlife in its path took weeks to fully surface. A humanitarian worker named Deckey Chandra, moving through Pulo Pakkat village in the days after the storm, found the body of a Tapanuli orangutan half-buried in mud. "They used to come to this place to eat fruits," he said. "But now it seems to have become their graveyard."
A new study has since put a number to the loss: an estimated 58 Tapanuli orangutans killed by four days of torrential rain and landslides — roughly 7 percent of a species whose entire global population numbers fewer than 800 individuals. The authors are careful to call this figure conservative. It does not account for the destruction of forest canopy, nor the longer-term scarcity of food as the ecosystem slowly recovers.
Professor Erik Meijaard, one of the study's authors, had initially estimated around 35 deaths when he spoke publicly in December. His revised figure nearly doubled that. Having seen photographs of the orangutan Chandra discovered — its face stripped of flesh by the force of the slide — Meijaard reflected on what the forest must have been like during the storm. "Even powerful orangutans are helpless," he said. "It must have been hellish."
The Tapanuli orangutan was not identified by science until 2017. It exists nowhere else on Earth, in a small patch of North Sumatran forest already under pressure from habitat loss and human encroachment. What the cyclone has made plain is that climate change now adds a different kind of threat — not the slow erosion of decades, but sudden, catastrophic loss. For a species with no margin left, the mathematics are unforgiving: 58 individuals means not just fewer bodies, but diminished genetic diversity, lost breeding potential, and knowledge of how to survive in a forest that is itself being remade. The Tapanuli orangutan's story, conservationists warn, is less an isolated tragedy than a preview.
In late November, Cyclone Senyar tore across the Indonesian island of Sumatra with such force that it killed more than a thousand people across Southeast Asia, making it the deadliest natural disaster the region had seen all year. What happened to the wildlife in its path took longer to understand. Weeks after the storm passed, a humanitarian worker named Deckey Chandra was moving through Pulo Pakkat village in central Tapanuli district when he found the body of what appeared to be a Tapanuli orangutan half-buried in mud and debris. "I have seen several dead bodies of humans in the past few days but this was the first dead wildlife," Chandra said. "They used to come to this place to eat fruits. But now it seems to have become their graveyard."
The discovery was part of a larger reckoning. Four days of torrential rain and landslides had swept across the island, and conservationists began noticing something troubling: sightings of Tapanuli orangutans, already the world's rarest great ape, had nearly vanished. The animals seemed to have disappeared. A new study published this week suggests why. Researchers estimate that 58 of the fewer than 800 remaining Tapanuli orangutans were killed in the cyclone—roughly 7 percent of the entire species wiped out in a single weather event. That figure, the study's authors emphasize, is conservative. It does not account for the damage to the forest canopy where the apes live and feed, nor does it capture the longer-term impact of reduced food availability as the ecosystem recovers.
Professor Erik Meijaard, managing director of Borneo Futures in Brunei and one of the study's authors, had initially estimated the death toll at around 35 orangutans when he spoke to the BBC in December—already what he called "a major blow to the population." His revised estimate nearly doubled that figure. Meijaard had seen photographs of the dead orangutan that Chandra found, images that stayed with him. "What struck me is that all the flesh had been ripped off the face," he said. "If a few hectares of forest comes down in massive landslides, even powerful orangutans are helpless and just get mangled. It must have been hellish in the forest at the time."
The Tapanuli orangutan is found nowhere else on Earth. The species was not formally identified by science until 2017, and its population has never been large. Fewer than 800 individuals remain, confined to a small region of forest in North Sumatra. They were already vulnerable—habitat loss, hunting, and human encroachment had pushed them to the brink. Climate change is now adding a new and more sudden threat. Extreme weather events like Cyclone Senyar do not discriminate between human and animal life, but for a species with such a small population, the mathematics of survival are unforgiving. Lose 58 individuals and you lose not just bodies but genetic diversity, breeding potential, and the accumulated knowledge of how to live in a forest that is itself being transformed.
The study's findings underscore something conservationists have long feared: that as the climate destabilizes and extreme weather becomes more frequent, species already living on the edge of extinction face not just slow decline but sudden collapse. The Tapanuli orangutan's story is not unique—it is a warning. For a species with fewer than 800 members, there is no margin for catastrophe, and catastrophe is becoming the new normal.
Notable Quotes
They used to come to this place to eat fruits. But now it seems to have become their graveyard.— Deckey Chandra, humanitarian worker who discovered a dead Tapanuli orangutan in Pulo Pakkat village
If a few hectares of forest comes down in massive landslides, even powerful orangutans are helpless and just get mangled. It must have been hellish in the forest at the time.— Professor Erik Meijaard, study author and managing director of Borneo Futures
The Hearth Conversation Another angle on the story
Why does a single weather event matter so much for this particular ape? Aren't orangutans resilient?
The Tapanuli orangutan isn't like other orangutans. There are fewer than 800 left on Earth, all in one small forest in Sumatra. When you lose 58 individuals in four days of rain, you're losing 7 percent of the entire species. That's not a setback—that's a wound that may not heal.
But the cyclone killed over a thousand people. Why focus on 58 apes?
Because humans can move, rebuild, have insurance and aid networks. An orangutan population that small has no redundancy. Every individual carries genes that might never be replaced. And the forest itself—their only home—was torn apart. The apes can't migrate elsewhere.
The study says 58 is a conservative estimate. What aren't they counting?
The canopy damage means less shelter and less food. Young orangutans that depended on mothers who died. The long-term stress of living in a degraded forest. The 58 is just the bodies they can document. The real cost is probably much higher.
Is this about climate change, or just bad luck?
Both. But climate change is making cyclones like Senyar more intense and more frequent. Bad luck used to be rare. Now it's becoming routine. For a species with no room to absorb shocks, routine catastrophe is extinction.
What happens next?
That's the question no one can answer yet. The species is still there, but it's being tested in ways conservation science never prepared for. Every storm now is a potential extinction event.