During the last ice age, from around 2.6 million to 12,000 years ago, Sumatran Rhinoceroses roamed the far reaches of east Asia. To the north, the squat, hairy, two-horned ungulates could be found as far as the Yellow River Valley in present-day China. To the south, their range extended into the tropics of present-day Indonesia. When global temperatures warmed at the dawn of the Holocene era, sea levels rose and separated Borneo, Java and Sumatra from mainland Asia, creating multiple distinct populations of the species. For millennia, Sumatran rhinos thrived on either side of the South China Sea.
But, as civilizations advanced and the human population surged in ancient East Asia, Sumatran rhinos numbered fewer and fewer. Forests shrank to make way for agriculture and development, and the animals were hunted for hides and horns. In the modern era, habitat destruction and pervasive poaching pushed the mainland population over the brink. The last known mainland Sumatran Rhino, Iman, died in Malaysia in 2019.
Today, less than 80 Sumatran rhinoceroses are left in Indonesia — and that number is decreasing. The population is scattered between a few protected areas in Sumatra and a province in Borneo. And their future is uncertain. Even if the remaining population is protected, limited genetic variability and the low breeding rate of Sumatran rhinos remain challenges to their survival.
