The one-horned rhinoceros, also called the Indian rhinoceros, is a large herbivorous mammal found mainly in the floodplain grasslands and wetlands of the Indian subcontinent. Its scientific name is Rhinoceros unicornis.
It is important because it is a major conservation success story in India, especially in Kaziranga National Park. At the same time, its population remains concentrated in a few protected areas, making it vulnerable to floods, poaching, disease and habitat pressure.
Habitat and Distribution
The one-horned rhinoceros is mainly found in the Terai-Duar grasslands, riverine forests and floodplain wetlands of India and Nepal.
In India, its major habitats include:
- Kaziranga National Park, Assam
- Manas National Park, Assam
- Orang National Park, Assam
- Pobitora Wildlife Sanctuary, Assam
- Jaldapara National Park, West Bengal
- Gorumara National Park, West Bengal
- Dudhwa National Park, Uttar Pradesh
The species prefers tall alluvial grasslands, swampy areas, riverbanks, reed beds and wetland-edge habitats. Its ecology is closely linked with floodplain systems, especially the Brahmaputra floodplains in Assam.
Conservation Status
The one-horned rhinoceros is listed as Vulnerable on the IUCN Red List.
Its legal protection is strong:
- IUCN Red List: Vulnerable
- CITES: Appendix I
- Wildlife Protection Act, 1972: Schedule I
India holds the largest population of the species. Assam, especially Kaziranga, is the main stronghold.
Kaziranga’s success is linked with strict anti-poaching measures, habitat protection and regular monitoring. However, concentration of a large population in one landscape also creates risk.
Ecological Importance
The one-horned rhinoceros is important for floodplain ecology.
As a large grazer, it helps maintain grassland structure by feeding on tall grasses and aquatic vegetation. Its movement and grazing patterns help keep parts of the floodplain open, which benefits several other grassland and wetland species.
The rhino landscape also supports species such as:
- wild water buffalo
- swamp deer
- hog deer
- elephant
- tiger
- Bengal florican
- wetland birds
- reptiles and amphibians
The species can be seen as an umbrella species. Protecting rhino habitats also protects floodplain grasslands, wetlands, riverine forests and several threatened species associated with the same ecosystem.
Specific Threats
The biggest historical threat to the one-horned rhinoceros was poaching for its horn. Although poaching has reduced in many areas due to strong enforcement, it remains a serious risk because rhino horn has illegal market value.
Other major threats include:
- habitat loss and fragmentation
- annual floods in Assam
- drowning of calves during extreme floods
- movement of rhinos outside protected areas during floods
- railway and road-related mortality
- invasive plant species in grasslands
- human-rhino conflict near park boundaries
- concentration of population in limited habitats
In Kaziranga, floods are natural and necessary for ecosystem renewal, but extreme floods can cause wildlife mortality and force animals to move towards highways and villages.
Conservation Measures
India has used a mix of strict protection, habitat management and translocation for rhino conservation.
Important measures include:
- anti-poaching camps and armed forest protection
- monitoring through camera traps, drones and patrols
- habitat management in grasslands and wetlands
- creation of highlands in flood-prone areas
- rhino translocation under the Indian Rhino Vision programme
- expansion of rhino populations beyond Kaziranga
- coordination between Assam, West Bengal, Uttar Pradesh and Nepal
The Indian Rhino Vision 2020 aimed to increase the rhino population in Assam and spread rhinos across more protected areas to reduce concentration risk.
Conclusion
The one-horned rhinoceros is one of India’s most important wildlife conservation species.
Its recovery shows the success of strong protection and habitat management, especially in Assam.
However, long-term conservation depends on reducing poaching risk, protecting floodplain grasslands, managing extreme floods and expanding secure rhino populations beyond a few concentrated habitats.



