Greater One-Horned Rhinoceros & Pobitora Wildlife Sanctuary

Subject: Environment

Context

Recently, photographs of Greater One-Horned Rhinoceros calves playing on higher ground at Pobitora Wildlife Sanctuary in Morigaon district, Assam, gained attention as low-lying areas of the sanctuary remained inundated due to heavy rainfall in Assam and neighbouring Arunachal Pradesh.

Greater One-Horned Rhinoceros (Indian Rhinoceros)

The Greater One-Horned Rhinoceros (Rhinoceros unicornis), also known as the Indian Rhinoceros, is the largest of the three Asian rhinoceros species and, along with the African White Rhinoceros, ranks among the largest rhinoceros species in the world.

Scientific Name

Rhinoceros unicornis

Distribution

Native to India and Nepal, primarily in the foothills of the Himalayas.
Historically inhabited the floodplains and forests of the Indus, Ganga, and Brahmaputra river basins.
Kaziranga National Park (Assam) supports the world’s largest population of Greater One-Horned Rhinoceroses.

Habitat

Prefers alluvial floodplains, tall grasslands, swamps, riverine forests, and wetlands.
Frequently inhabits areas close to water bodies and mineral licks.

Key Features

Largest Asian rhinoceros species.
Adult males weigh around 2,200 kg.
Height: 170–186 cm; Length: 3.7–3.8 m.
Possesses a single black horn, typically 20–60 cm (8–25 inches) long.
Thick grey-brown skin with prominent folds gives an armour-plated appearance.
Generally solitary, except females with calves.
Primarily a grazer, feeding mainly on grasses, along with leaves, fruits, branches, and aquatic plants.

Conservation Status

IUCN Red List: Vulnerable

Pobitora Wildlife Sanctuary

Location

Situated in Morigaon district, Assam.
Declared a Wildlife Sanctuary in 1998.
Comprises the Pobitora Reserve Forest and Raja Mayong Reserve Forest.
Lies within the floodplains of the Brahmaputra River, an ecologically rich wetland ecosystem.

Significance

Known for the highest density of Greater One-Horned Rhinoceroses in India.
Included under the Government of India’s Indian Rhino Vision 2020 (IRV 2020) programme, aimed at increasing and securing rhino populations across Assam through conservation and translocation.

Vegetation

Dominated by alluvial grasslands, marshes, and dense stands of tall elephant grass.
Around 72% of the sanctuary consists of wet savannah grassland, comprising species such as:
- Arundo donax
- Erianthus ravennae
- Phragmites karka
- Imperata cylindrica
- Saccharum spp.
Water hyacinth (Eichhornia crassipes), an invasive aquatic weed, poses a major ecological challenge by forming dense mats that adversely affect waterfowl and aquatic ecosystems.