The Greater One-horned Rhinoceros (Rhinoceros unicornis), also known as the Indian Rhino, is the largest of the three Asian rhino species. It is distinguished by its single black horn and its grey-brown hide with skin folds that give it an “armor-plated” appearance. Once widespread across the entire Indo-Gangetic Plain, the species was driven to the brink of extinction in the early 20th century but has staged a significant recovery due to strict conservation efforts.
Physical Characteristics and Biology
- The Horn: Unlike the horns of many other animals, the rhino’s horn is not bone; it is composed of keratin, the same protein found in human hair and fingernails.
- Skin Folds: Large folds of skin at the neck, shoulders, and rump are characteristic of this species.
- Size: It is the fourth largest land animal, with males weighing between 2,000 kg and 2,700 kg.
- Senses: It has a keen sense of smell and hearing but relatively poor eyesight.
- Habitat: It is a semi-aquatic species, preferring alluvial grasslands and riverine forests. It is an excellent swimmer and frequently wallows in mud to regulate body temperature and protect against insects.
Conservation Status and Legal Protection
The Indian Rhino is a “flagship species” and is frequently featured in UPSC Prelims regarding its status and habitat.
| Framework | Status/Category |
| IUCN Red List | Vulnerable |
| Wildlife Protection Act, 1972 | Schedule I (Highest Protection) |
| CITES | Appendix I (Strictly prohibits commercial trade) |
| Population Trend | Increasing (India and Nepal host over 4,000 individuals) |
Indian Rhino Vision 2020 (IRV 2020)
Launched in 2005 by the Forest Department of Assam in partnership with WWF-India and the International Rhino Foundation, this ambitious project aimed to increase the rhino population in Assam.
- Target: To reach a population of 3,000 rhinos spread across seven protected areas in Assam by the year 2020.
- Strategy: Translocating rhinos from high-density areas (Kaziranga and Pobitora) to potential habitats like Manas National Park to reduce the risk of localized disasters or disease.
- Result: While the population target was met, the goal of spreading them across seven areas was only partially successful.
Key Habitats and Protected Areas
Assam is the global stronghold for the species, hosting approximately 70% of the world’s population.
- Kaziranga National Park (Assam): A UNESCO World Heritage Site, it holds the highest concentration of One-horned Rhinos globally.
- Pobitora Wildlife Sanctuary (Assam): Known for having the highest density of rhinos in the world.
- Manas National Park (Assam): A site where the population was restored through translocations under IRV 2020.
- Orang National Park (Assam): Often called the “Mini Kaziranga” due to its similar landscape and rhino population.
- Jaldapara and Gorumara National Parks (West Bengal): Important habitats outside of Assam.
- Dudhwa National Park (Uttar Pradesh): A successful reintroduction site for the species in North India.
Major Threats to Survival
- Poaching: Driven by the illegal demand for rhino horns in traditional medicine markets in East Asia (despite no proven medicinal value).
- Habitat Fragmentation: Encroachment for agriculture and the expansion of human settlements reduce the available grazing area.
- Flooding: Annual floods in the Brahmaputra valley (Kaziranga) are necessary for the ecosystem but cause high mortality of calves and elderly rhinos.
- Invasive Species: The spread of Mimosa invisa and other weeds chokes the native grasses that rhinos feed on.
- Genetic Bottleneck: Since the current population originated from a very small number of survivors in the early 1900s, low genetic diversity is a long-term concern.
Comparison: Indian vs. African Rhinos
UPSC aspirants should be able to differentiate the Indian Rhino from its African cousins.
| Feature | Greater One-horned Rhino | African Rhinos (White/Black) |
| Number of Horns | One | Two |
| Skin Appearance | Folded/Armor-plated | Relatively smooth |
| Upper Lip | Prehensile (hooked) for browsing | Square (White) or Pointed (Black) |
| Location | India and Nepal | Sub-Saharan Africa |
Trivia for UPSC Prelims
- New Delhi Declaration on Asian Rhinos: In 2019, India, Bhutan, Nepal, Indonesia, and Malaysia signed this declaration to cooperate on rhino conservation and management.
- World Rhino Day: Celebrated on September 22 every year.
- State Symbol: The One-horned Rhino is the State Animal of Assam.
- DNA Index System (RhODIS): India uses a DNA database for rhinos to help track poached horns and assist in forensic investigations to convict poachers.