Long-Term Monitoring: Measuring the Future of the Sumatran Tiger
Effective Sumatran tiger conservation depends on knowing whether tiger populations are stable, increasing, or continuing to decline. Yet obtaining reliable population estimates for this critically endangered species is exceptionally challenging. Sumatran tigers occur at very low densities, even in the most intact, prey-rich, and well-protected forests. Detecting enough individuals to understand population trends therefore requires sustained effort over time.
Most Sumatran tiger studies to date have relied on short, three- to four-month “snapshot” camera-trap surveys. While these surveys provide valuable information about tiger presence, distribution, and individual identification, they can produce highly uncertain population estimates when conducted over such a short period. When estimates from different locations and years are combined, they do not yet provide a sufficiently clear picture of the overall status and trajectory of the Sumatran tiger. For example, the most recent island-wide estimate has been reported as 173–883 tigers—a range of more than fivefold between the lower and upper estimates.
At Hutan Harimau, we believe that conservation decisions must be supported by stronger and more reliable evidence. We are therefore committed to multi-year, systematic camera-trap monitoring designed not simply to detect tigers, but to understand how populations change over time. Repeated surveys allow us to improve estimates of tiger abundance and occupancy, identify population trends, assess habitat use, monitor threats, and evaluate whether conservation interventions are actually delivering results.
Monitoring the Kerinci Seblat–Batanghari Landscape
We are currently implementing long-term camera-trap monitoring across the Kerinci Seblat–Batanghari landscape, covering approximately 60,000 hectares (600 km²) of tiger habitat. The monitoring network is designed to generate consistent data over multiple years, creating a robust baseline against which future changes can be measured.
This landscape is not only important for Sumatran tigers, but also supports a wider community of wildlife and connects protected areas with forests used by local communities. By combining camera-trap data with information on prey, habitat conditions, forest threats, and local ecological knowledge, we aim to build a more complete understanding of the ecosystem on which tigers depend.
Long-term monitoring is more than counting tigers. It is how we measure whether conservation is working.
If tiger numbers increase, survival improves, occupancy expands, or threats decline, long-term data can help demonstrate those changes. If populations continue to decline, the same monitoring provides an early warning, allowing conservation actions to be adapted before it is too late.
For Hutan Harimau, every camera trap is therefore part of a much larger commitment: to replace short-term snapshots with long-term evidence, and to ensure that conservation success is measured not by the activities we undertake, but by the populations and forests we are able to protect.
We cannot protect what we cannot measure. And we cannot know whether conservation is succeeding without monitoring the tiger over time.