Greater One-horned Rhino

The Greater One-horned Rhino is a massive herbivore native to the floodplains of the Indian subcontinent, easily recognized by its single horn and armor-like folded skin. It is the largest of the Asian rhino species and a symbol of successful conservation after being brought back from near-extinction. It primarily inhabits tall grasslands and riverine forests in protected areas of India and Nepal.

North India and Nepal, primarily in the Brahmaputra and Terai floodplains

Restricted to the Terai grasslands and Brahmaputra floodplains, primarily in Assam (India), West Bengal, and lowland Nepal (Chitwan and Bardia National Parks).

Altitude and depth

0-300m, generally in lowland floodplain areas

Seasonal movements

No true migration, but seasonal movement occurs between higher and lower ground during monsoon flooding.

Alluvial floodplain grasslands, riverine forests, and adjacent swamps and marshes; often found near rivers and wetlands for wallowing.

Adaptations to its environment

Thick, armor-like skin folds provide protection in dense vegetation; semi-aquatic habits and wallowing help regulate body temperature and deter parasites; excellent swimming ability allows navigation of flooded habitats.

Classified as Vulnerable by IUCN; the species has recovered from fewer than 200 individuals in the early 20th century to over 4,000 today due to intensive protection, though it remains vulnerable to poaching and habitat loss.

Estimated population

Approximately 4,000 individuals, with a stable to slightly increasing trend due to conservation efforts.

Poaching for horn (used in traditional medicine), habitat loss due to agricultural encroachment, floods, and human-wildlife conflict.

Diseases and parasites

Susceptible to parasitic infections such as ticks and gastrointestinal worms; anthrax outbreaks have also affected populations in the past.

Protected in national parks such as Kaziranga (India) and Chitwan (Nepal); anti-poaching patrols, translocation programs to establish new populations, and strict legal protection under national wildlife laws.

Recommended actions

Expand and connect protected habitats, strengthen anti-poaching enforcement, mitigate human-wildlife conflict, and continue genetic monitoring to maintain population diversity.

Grey-brown skin with thick folds resembling armor plates, especially around the shoulders and legs; a single black horn on the snout, typically 20-60 cm long.

Size

Shoulder height 1.7-2 m; body length 3.1-3.8 m

Weight

1,800-2,700 kg, with males generally larger than females

Distinctive features

Distinguished from African rhinos by its single horn and pronounced skin folds that create a 'armored' appearance; larger and bulkier than the Javan rhino, its closest living relative.

Differences between males and females

Males are generally larger and more muscular than females, with thicker necks; horn size can vary but is not strongly sex-linked.

Mostly solitary, though loose aggregations may form at wallows or feeding grounds; males are territorial and may fight for dominance.

When it is active

Primarily crepuscular and nocturnal, with periods of activity in early morning and late evening; rests during the hottest parts of the day.

Diet

Herbivorous, feeding on grasses, leaves, fruits, aquatic plants, and crops; known to graze extensively in tall grasslands.

Communication

Communicates through vocalizations such as snorts, honks, and bleats, as well as scent marking via dung piles and urine spraying.

Interactions with other species

Few natural predators aside from tigers, which occasionally prey on calves; competes with domestic livestock for grazing land in some areas.

Role in its ecosystem

Acts as a keystone grazer, shaping grassland structure and creating microhabitats used by other species such as birds and smaller herbivores.

Breeding occurs year-round with no strict season; gestation lasts about 15-16 months, typically resulting in a single calf.

Raising the young

Calves are cared for solely by the mother, nursing for up to 18 months and staying with her for 2-4 years before independence.

Maturity and lifespan

Sexual maturity around 4-7 years for females and 7-9 years for males; lifespan up to 35-45 years in the wild, sometimes longer in captivity.

Classification

Class: Mammalia > Order: Perissodactyla > Family: Rhinocerotidae > Genus: Rhinoceros > Species: Rhinoceros unicornis

Scientific synonyms

Rhinoceros indicus

Recent studies

Recent studies have used satellite tracking and genetic analysis to monitor population connectivity and inform habitat management strategies in Assam and Nepal.

Genome and DNA

Diploid chromosome number of 2n=82; genetic studies have been used to assess population diversity and inform translocation strategies.

Compared with similar species

Closely related to the Javan rhino but larger and more robust, with more pronounced skin folds; unlike African rhinos, it has only one horn rather than two.

Despite their bulk, these rhinos are excellent swimmers and can submerge completely; their skin folds were historically mistaken for natural armor plating by early explorers.

Where and how to see it

Best observed in Kaziranga National Park (India) or Chitwan National Park (Nepal) during early morning safaris in the dry season (November-April) when grasses are shorter.

Risks to humans

Generally avoids humans but can become aggressive if threatened or cornered, capable of causing serious injury with its horn or body charge.

Human uses

Historically hunted for its horn used in traditional Asian medicine; today primarily valued for ecotourism revenue in protected reserves.

Myths and legends

In some South Asian traditions, the rhino's horn was believed to have medicinal or aphrodisiac properties, fueling demand that historically drove poaching.