Extreme Rain Kills 58 Tapanuli Orangutans, Wiping Out 7% of the Species
Updated
Updated · The Guardian · Jun 10
Extreme Rain Kills 58 Tapanuli Orangutans, Wiping Out 7% of the Species
3 articles · Updated · The Guardian · Jun 10
Summary
58 Tapanuli orangutans died after more than 1,000mm of rain fell in four days in North Sumatra in November 2025, according to a new study.
Satellite analysis tied the deaths to Cyclone Senyar-triggered landslides in the Batang Toru ecosystem, where scientists said human-caused climate change increased rainfall intensity by up to 50%.
About 8,300 hectares of key forest habitat—11.7% of the West Block—were also destroyed, compounding pressure from mining, palm oil plantations and a hydropower project.
With only about 800 Tapanuli orangutans left, researchers said a 7% species-wide loss is a severe demographic shock; earlier work suggested annual losses of 1% could eventually cause extinction.
Indonesia has temporarily paused major industrial activity in Batang Toru, while researchers are urging a land-use moratorium, expanded protected areas and international biodiversity funding.
Is the global push for electric vehicles paradoxically accelerating the extinction of the world's rarest great ape?
Can conservation efforts outpace the combined threats of corporate interests and increasingly extreme weather?
Indonesia revokes some mining permits, yet plans to strip protection from the orangutan's last forest. What is the real plan?
Over 1,100 Dead: How Cyclone Senyar and Decades of Deforestation Unleashed Catastrophe in Sumatra and Pushed the Tapanuli Orangutan to the Brink
Overview
In late November 2025, Cyclone Senyar struck northern Sumatra, unleashing heavy rainfall that led to widespread flooding and landslides. This disaster claimed over 1,100 lives across Asia within a week, with hundreds more missing and search and rescue operations becoming extremely dangerous. The catastrophe also caused severe damage to Sumatra’s delicate ecosystems, especially devastating key habitats in the Batang Toru region. As a result, the environment of the critically endangered Tapanuli orangutan was significantly altered, with forest areas below 300 meters—vital for their survival—being severely affected.