Sumatran tiger conservation is guided by precise estimates and trends of their populations. However, obtaining data on this critically endangered species is extremely challenging because they occur at very low densities in even the best protected, most prey-rich habitats.
It is therefore not surprising that the 3-4 month “snapshot” camera-trap surveys, which comprise most Sumatran tiger studies to date result in very imprecise estimates. Cumulatively, these estimates do not paint a very clear picture of Sumatran tiger status. For example, the most recent island-wide estimate is 173-883 tigers, a wide range that varies by over 500%.
Further convoluting the picture is the reality that tiger numbers naturally fluctuate in response to factors such as prey availability and intraspecific competition. Measuring changes in tiger numbers by comparing two distant points can be very misleading, particularly when differences in sampling methods are overlooked. Any inference from such an analysis is entirely dependent upon the stage of the tiger population cycle when the so-called baseline estimate was obtained. Starting from a peak and ending on a trough will create the illusion of a downward trend in tiger numbers. Start from a trough and end on a peak, an upward one.
Hutan Harimau is committed to conducting multi-year surveys to inform more accurate estimation of Sumatran tiger numbers. Only with multi-year surveys can we make better estimates of tiger distribution, survival, and site fidelity.