The white rhinoceros is native to Africa and ranks as the second largest land-dwelling mammal, according to the World Wildlife Federation. As of 2014, only four northern white rhinos exist in the wild in the Democratic Republic of the Congo. Approximately 20,000 southern white rhinos are heavily concentrated in Kenya, South Africa, Zimbabwe and Namibia.
White rhinos get their name from the Dutch word "weit," or wide, which refers to the animals' broad upper lip. The squared shape helps them position their lip close to the ground when grazing. Contrary to their names, white rhinos have pale gray or yellow-brown skin. Adult males, or bulls, typically weigh between 2,000 and 3,600 kilograms, making them the largest rhino species. White rhinos have one short and one long horn, and the latter can grow up to 60 centimeters on average.
In the wild, bulls often live alone and mark their domain by urinating, tearing up nearby plants and defecating on existing dung piles. Female rhinos and immature males may be allowed into marked territory, but bulls often try to prevent receptive or pregnant females from vacating the area until breeding is complete. White rhinos mate year round with a gestation period of about 16 months, producing a single calf. These highly social mammals reproduce every two or three years and have a potential lifespan of up to 40 years.