JAVAN RHINO

The Javan Rhino

All 74 Javan rhinos on Earth live in one place. One. A single national park in Java — Ujung Kulon — is the last refuge of the rarest large mammal on the planet. Not because they can't live elsewhere, but because everywhere else, they were killed for their horns.

The Javan rhino is a species that survived ice ages, extinctions, and millennia of human expansion, only to be reduced to a single population in one corner of one island. There is no other population in the wild. No captive backup. No second chance. If something catastrophic happens at Ujung Kulon — a volcanic eruption, a disease outbreak, a tsunami — the Javan rhino goes with it.

This is one of the starkest examples of how vulnerable a species can become. Every other threatened species on this list has multiple populations spread across multiple countries. The Javan rhino has one group, one location, one stretch of coastal forest.