CAMERA TRAPS STUDY CAUGHT SOMETHING NO ONE EXPECTED IN SUMATRA’S FORESTS.
- carl83495
- 4 hours ago
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For years, conservationists thought they knew which corners of Sumatra protected a species most at risk of disappearing. Many expected the last strongholds of this critically endangered species were tucked safely inside national parks. But sometimes nature hides its biggest surprises in unexpected places.
A camera trap project in the Leuser Ecosystem outside the boundaries of Gunung Leuser National Park revealed exactly that. When researchers set out a wide network of camera traps in forests receiving less attention, they did not expect this outcome. What they found forced them to rethink long-held assumptions about Sumatra’s most elusive apex predator.
A Sumatran camera-trap study rewriting assumptions
For the survey, researchers set a grid of paired infrared cameras spread across a large area and monitored it for periods during 2023 and 2024. The cameras captured almost three times more images of the Critically Endangered Sumatran tiger than similar studies in the past.
The research took place in the Leuser Ecosystem in forests outside of the borders of the Gunung Leuser National Park in Sumatra.
These provincially protected and mixed-use areas – areas frequently threatened by logging, agricultural expansion and development – revealed high tiger densities, estimated at 1.42 to 2.35 tigers per 100 km². That is 2.5 to four times higher than similar surveys in other parts of Sumatra.
“We documented a robust tiger population, apparently among the healthiest on the island,” said Dr Joe Figel, a conservation biologist who works with Indonesian wildlife and forestry agencies.
Across the multi-year survey, the team identified 27 individuals: 14 females, 12 males and one of an unknown sex. The strong female presence suggests a stable social structure and high-quality habitat, the kind of environment where females can successfully raise several litters over a decade.
A resident female Sumatran tiger grooming one of her two large male cubs in October 2023. Credit: Figel et al. 2025, BKSDA-Aceh, DLHK
Camera trap snapshot of a tiger in the Leuser ecosystem. Credit: Figel et al. 2025, BKSDA-Aceh, DLHK.
In a 2023 session, they captured three different sets of cubs. Two siblings photographed together as youngsters were later seen separately as adults.
Figel says the surge in tiger detections is a result of several ecological factors working together. Leuser still contains crucial stretches of lowland and hill forest where prey species reach their highest densities in Sumatra.
The study reveals an urgent message: some of Sumatra’s most important habitats lie outside national parks. These forests may hold the future of one of the world’s most endangered big cats, but only if protected.
ThisWildEarth