By Rachel Roberts
This past December, one of the few remaining northern white rhinoceroses died at the San Diego Zoo. According to many scientists, it is very unlikely that any more will be born. The remaining five northern white rhinos (four females and one male) can be found across the world at the San Diego Zoo, the Czech Republic, and Kenya’s Ol Pejeta Conservancy.
The white rhino is divided into two subspecies: the northern white rhino, and the southern white rhino. The southern white rhino is considered a near-threatened species, and can be found in only four countries: South Africa, Namibia, Zimbabwe, and Kenya.
During the 19th century, southern white rhinos were believed to be extinct. In 1985 however, a group of about 100 southern white rhinos were found in Kwazulu-Natal, South Africa. Since then, scientists and conservationists have been working diligently to increase southern white rhino populations. Currently, about 20,000 exist in protected areas and private game reserves.
White rhinos differ from their black rhino counter parts not because of color (both are actually grey), but in lip shape. While the black rhino has a pointed upper lip, white rhinos have a square shaped one. This difference in lip shape primarily reflects differences in their diets. Black rhinos obtain most of their food by grazing on trees and bushes, and often pluck fruit and leaves from branches. In contrast, white rhinos graze on grasses. Since their large heads are often lowered to the ground, square-shaped lips are more beneficial for their diet.
Many rhinos, including the white and black rhino, have declined significantly in the last couple of decades due to increased poaching and hunting. Rhino horns are highly valuable because they are used for traditional medicinal purposes in Asia. The horn, which is the defining feature of the rhino, has ultimately become its downfall, as commercial poaching for the horn has caused severe damage to rhino populations.
Interbreeding between northern and southern white rhinos, to save northern white rhino genes, has been proposed by a number of scientists. Although the pure northern white rhino would be lost, some of its genes would remain in the offspring.
Matthew Lewis, a senior program officer for African species conservation at the World Wildlife Fund, believes that the offspring of these interbred rhinos would have relatively few difficulties adjusting to life in the wild. In the past, rhinos have proven to be generally adaptable to the wild once reintroduced. Lewis believes that although northern white rhinos have been “absent from the wild for a number of years, having them back would be good for the ecosystem.” Rhinos help to diversity plant life, and help to create grazing spots for other animals.