The Javan rhinoceros, one of the world’s rarest large mammals, faces unique challenges for its survival. This species is an entirely herbivorous browser. Its feeding habits are intricately linked to its existence within its specific habitat, playing a fundamental role in its overall health and the health of its ecosystem. Understanding what and how these rhinos eat provides insight into their ecological needs and conservation efforts.
Primary Plant-Based Diet
The diet of a Javan rhino is diverse, primarily consisting of leaves, twigs, shoots, and small branches from a wide variety of plants. They consume young foliage and fallen fruits, adapting their intake based on availability within their forest environment. They consume an estimated 50 kilograms (110 pounds) of food daily. This includes parts of tree saplings, shrubs, and lianas, with a preference for plants found in sunnier forest clearings. Specific plants known to be part of their diet include various fig species (Ficus), Glochidion zeylanicum, Desmodium umbellatum, and stinging nettle family members like Laportea stimulans.
Foraging Habits and Preferences
Javan rhinos demonstrate selective browsing behavior, consuming over 100 different plant species. They prefer young, succulent growth, which provides easier digestion and higher nutrient content. A distinguishing feature is their prehensile upper lip, which functions like a finger to grasp and pull vegetation, allowing them to efficiently strip leaves from branches. To access food, rhinos may knock down saplings or bend taller plants, even by pushing against them with their heads or using their bodies. These rhinos are often most active during dawn, dusk, or throughout the night, using these times to forage. Their movement through dense vegetation also involves creating paths, which helps them access various food sources.
Dietary Significance and Habitat
The Javan rhino’s diet provides necessary nutrients and minerals for its health and large body. Like some other rhino species, they require salt, which they may obtain from natural salt licks or by drinking seawater where salt licks are absent. Their survival is directly tied to the availability of preferred food plants within their limited range, primarily Ujung Kulon National Park in Indonesia. Their browsing activities shape the forest undergrowth by consuming and trampling vegetation, creating space for new plants to grow, and their feces also disperse seeds, contributing to forest regeneration and biodiversity. However, invasive species like the Arenga palm can reduce the availability and diversity of their preferred food plants, posing a challenge to their habitat.