There’s no creature on earth like the Sumatran rhino.

With a thin coat of iron-tinged hair and a lifestyle adapted to the mountainous rain forests of Indonesia, these are the smallest rhinos on earth. They are also the most endangered rhino species—and isolation threatens to wipe them out.

Experts now estimate that around 80 of these rare creatures remain between the islands of Sumatra and Indonesian Borneo, and the survivors are split into around a dozen subpopulations with no gene exchange.

“They’re in tiny little pockets, some as small as one and two left in the forest,” says CeCe Sieffert, deputy director at the International Rhino Foundation.

In fact, the remaining rhinos have become so fragmented, the world’s experts now consider