Both black and white rhinoceroses are actually grey. They are different not in colour but in lip shape. The black rhino has a pointed upper lip, while its white relative has a squared lip. The difference in lip shape is related to the animals' diets. Black rhinos are browsers that get most of their sustenance from eating trees and bushes. They use their lips to pluck leaves and fruit from the branches. White rhinos graze on grasses, walking with their enormous heads and squared lips lowered to the ground.

Except for females and their offspring, black rhinos are solitary. Females reproduce only every two and a half to five years. Their single calf does not live on its own until it is about three years old.

Black rhinos feed at night and during the gloaming hours of dawn and dusk. Under the hot African sun, they take cover by lying in the shade. Rhinos are also wallowers. They often find a suitable water hole and roll in its mud, coating their skin with a natural bug repellent and sunblock.

Rhinos have sharp hearing and a keen sense of smell. They may find one another by following the trail of scent each enormous animal leaves behind it on the landscape.

Black rhinos boast two horns, the foremost more prominent than the other. Rhino horns grow as much as three inches a year and have been known to grow up to five feet long. Females use their horns to protect their young, while males use them to battle attackers.

The prominent horn for which rhinos are so well known has also been their downfall. Many animals have been killed for the hard, hairlike growth, which is revered for medicinal uses in China, Taiwan, Hong Kong, and Singapore. The horn is also valued in North Africa and the Middle East as an ornamental dagger handle.

The black rhino once roamed most of sub-Saharan Africa, but today is on the verge of extinction due to poaching fueled by commercial demand for its horn.