The last 70 Javan rhinos on Earth confined to one peninsula. Living in a volcanic shadow with zero genetic diversity, facing extinction from a single eruption.
A species on the brink
The entire global population of the Javan rhinoceros (Rhinoceros sondaicus) is confined to Ujung Kulon National Park on the westernmost tip of Java, Indonesia. This population is estimated to be around 76 individuals. The species once ranged across Northeast India and Southeast Asia, but the last individual outside of Indonesia was poached in Vietnam in 2010. Intensive monitoring in the park began in 1967 when only about 25 rhinos remained. While the population has slowly increased, it faces extreme vulnerability due to its concentration in a single location.
A significant threat comes from the nearby Anak Krakatau volcano, located in the Sunda Strait about 30 miles away. A major eruption could trigger a tsunami capable of wiping out most of the rhinos' low-lying habitat and the animals themselves. The catastrophic 1883 eruption of Krakatau produced a tsunami that inundated the peninsula, and a similar event today would be devastating for the species. The 2018 eruption and subsequent tsunami damaged park buildings and killed two park officials, showing the danger.
The problem of genetic isolation
The small and isolated size of the Ujung Kulon population has led to critically low genetic diversity. Studies indicate that the rhinos alive today are descended from the few that recolonized the area after the 1883 Krakatau eruption. This lack of genetic variation, a result of inbreeding, increases the rhinos' susceptibility to disease and may lead to congenital defects. There are no Javan rhinos in captivity anywhere in the world, which means the survival of the entire species rests on this single, genetically compromised population.
Conservation efforts face numerous other challenges. Poaching is a persistent threat; recent investigations revealed that poaching groups may have killed as many as 26 rhinos between 2019 and 2023. Another issue is the invasive Arenga palm (Arenga obtusifolia), which has overtaken large parts of the park. This palm crowds out the native plants that Javan rhinos rely on for food, effectively shrinking their available habitat. Disease is also a concern, with potential transmission from wild water buffalo in the park.
💡Fun Facts
The Javan rhino's scientific name, *Rhinoceros sondaicus*, refers to the Sunda region of Southeast Asia.
Unlike their African relatives, only male Javan rhinos typically have a horn, which is the smallest of any rhino species, usually less than 10 inches long.
They are primarily browsers and have been documented eating more than 300 different plant species.
The skin of a Javan rhino has loose folds that give it an armor-plated appearance.
The park is generally open to visitors, but may be closed periodically for security and monitoring. Check with the park authority before visiting.
Admission
Entry permits are required. Ticket prices for foreign visitors are approximately IDR 150,000–225,000 (USD 10-15).
Accessibility
The park consists of lowland rainforest, coastal areas, and swamps. Access to many areas is by boat, and terrain can be challenging with rough, muddy trails.