Indian rhinoceros

The Indian rhinoceros, known scientifically as Rhinoceros unicornis, is a massive mammal native to the Indian subcontinent.

It is also called the greater one-horned rhinoceros or the great Indian rhinoceros. This species is a vital part of the ecosystems found in the Indo-Gangetic Plain. It is the largest rhinoceros living in Asia. In fact, it is the second-largest living rhinoceros in the world. Only the Asian elephant is larger than this animal.

Physically, the Indian rhinoceros has very distinct features. Its skin is thick and grey-brown in color. It features prominent pinkish skin folds across its body. These folds are pink because of the rich presence of blood vessels underneath the tissue. These folds serve a biological purpose by increasing surface area. This helps the animal regulate its body temperature.

The rhino is nearly hairless, except for eyelashes, ear fringes, and a tail brush. Its upper legs and shoulders are covered in wart-like bumps.

A single horn sits on its snout. This horn is made of pure keratin. It begins to appear after the animal is about six years old. While adults often have long horns, captive rhinos sometimes have horns worn down to a thick knob.

The biology and behavior of the rhino are shaped by its environment. Most Indian rhinoceroses are solitary animals. They typically only associate with others during the breeding season or when rearing calves. They are grazers that eat grass, but they also consume twigs, leaves, branches, shrubs, flowers, fruits, and aquatic plants. They are most active during the early mornings, late afternoons, and at night. During hot days, they prefer to rest. They are excellent swimmers and can run at high speeds for short periods.

While they have excellent hearing and smell, their eyesight is relatively poor.

Reproduction and life cycles follow specific patterns. A female rhino has a gestation period of about 15.7 months. She typically gives birth to a single calf. The interval between births is usually between 34 and 51 months.

In captivity, these animals can live for up to 47 years. In the wild, they face natural threats like tigers, which may target unguarded calves. They also face health challenges from diseases like anthrax. Parasites such as leeches, ticks, and nematodes can also affect them.

The history of the Indian rhinoceros includes significant scientific study. Carl Linnaeus first described the species in 1758 using the name Rhinoceros unicornis. The name "rhinoceros" comes from the Greek words "rhino," meaning nose, and "keras," meaning horn. The Latin term "unicornis" means "one-horned."

Evolutionarily, the ancestors of modern rhinos split from the ancestors of horses, or Equidae, around 50 million years ago. The genus Rhinoceros is more closely related to the Sumatran rhinoceros than to African rhinoceroses. Fossil evidence shows that the genus Rhinoceros dates back to the Late Miocene, roughly 8 to 9 million years ago.

Conservation efforts have changed the fate of this species. In the early 1900s, the population dropped to as low as 100 individuals. This was due to excessive hunting and agricultural development. However, government conservation measures have helped the numbers rise. In the early 1990s, the global population was only between 1,870 and 1,895. By March 2025, the population was estimated at 4,075 individuals.

Of these, 3,323 live in India and 752 live in Nepal. Large populations exist in Kaziranga National Park and Chitwan National Park.

Today, the Indian rhinoceros is listed as Vulnerable on the IUCN Red List. This status is due to a fragmented population that is restricted to less than 100,000 square kilometers. Even though numbers are increasing, poaching remains a continuous threat. The species relies on protected areas like the Terai and the Brahmaputra basin.

Maintaining these habitats is essential for their survival. Their presence helps maintain the health of the alluvial grasslands they inhabit.