RHINOCEROS EXTINCTION
The Northern White Rhinoceros: Only A Handful Remain
The Northern White Rhino Is Almost Certain To Go Extinct—With Other Species To Follow
With the death last week of a 34-year-old male named Suni, the world’s population of northern white rhinoceroses dropped to six, and the rhino subspecies lumbered closer to the abyss of extinction. Suni was one of two breeding males at the Ol Pejecta Conservancy in Kenya. He appears to have died of natural causes. Even before Suni’s death, many scientists were skeptical that the small number of remaining northern whites could produce enough offspring with sufficient genetic diversity to allow the subspecies to survive.
Genetic diversity becomes a problem for any population that is close to extinction or extirpation because in order to produce young, individuals must mate with close relatives. This is called inbreeding. Eventually, inbreeding causes every member of the population to end up being a genetic near-duplicate of every other member, making the entire group vulnerable to illness and birth defects.
Northern white rhinos (Ceratotherium simum cottoni) once ranged over parts of northwest Uganda, southern Chad, southwest Sudan, eastern Central African Republic, and northeastern Democratic Republic of the Congo. This range is separated by a vast distance from that of the southern white rhino (Ceratotherium simum simum), which can now be found almost exclusively in South Africa. The white rhino is the largest rhinoceros species in the world, weighing up to 2,300 kg (5,100 pounds). But some scientists claim that the northern and southern white rhinos should be classified as two separate species altogether.
In contrast to the almost-extinct northern white rhino, the southern white is the most numerous rhinoceros species on earth, with about 20,000 individuals in existence. However, due to overhunting, the southern white rhino itself almost went extinct prior to 1900. Only a strong and concerted conservation effort—one of the world’s first and most successful wildlife conservation projects—restored the species to its current robust numbers. Unfortunately, those numbers have begun to decline again due to poaching, or illegal hunting, for rhino horn, which is used in Asian folk medicines and now fetches prices that exceed those of equivalent weights of gold or platinum.
In fact, all five rhinoceros species—white, black, Indian, Javan, and Sumatran—and their subspecies are in grave danger due to the illegal and growing trade in rhinoceros horn. Vietnam’s last Javan rhino was killed by a poacher in 2011, leaving the species with only around 40 individuals remaining on the Indonesian Island of Java. The black rhino’s western subspecies was declared extinct in 2013. The Critically Endangered Sumatran rhinoceros is estimated to number fewer than 200, all of them living in Indonesian Sumatra, while fewer than 2,000 Indian rhinos are thought to survive in India and Nepal. The three remaining subspecies of African black rhino—all Critically Endangered—number fewer than 4,000, a 90 percent decrease since 1960.
Authorities in many countries are struggling to protect their remaining rhinos. However, poachers motivated and financed by stratospheric prices for illegal rhino horn have been using increasingly sophisticated weapons and technology, including helicopters, in order to locate an kill the animals. It has been difficult for law enforcement authorities to keep up. As of this writing, in 2014 791 rhinos have been killed by poachers in South Africa, the country that by far is home to the most of these huge animals. In 2013, just over 1,000 South African rhinos—mostly southern whites, but also some black rhinos—were taken by illegal hunters.
