Endangered Mammals - Rhinoceros

Rhinoceros are among the largest land mammals. They weigh up to 8,000 pounds—as much as fifty average-sized men—and are herbivorous grazers. The name rhinoceros is made up of two Greek words meaning "nose" and "horn," and rhinos are in fact the only animals on Earth that have horns on their noses. Figure 7.8 shows an African white rhinoceros with two horns. The female may be identified by her longer, more slender primary horn.

Rhinoceros have roamed the land for more than 40 million years, but in less than a century, humans—their only predators—have reduced populations to dangerously low levels. There are five species of rhinoceros—the black rhino (African), white rhino (African), Sumatran rhino (found in Borneo, Malaysia, and Sumatra), Javan rhino (found in Indonesia and Vietnam), and Indian rhino (found in both India and Nepal). Certain rhino species can be divided into distinct subspecies. For example, the Javan rhino has two subspecies, one found in Vietnam, the other in Indonesia. The Vietnamese subspecies consists of only one tiny population of five to seven individuals, and was thought extinct until this tiny population was discovered in 1999. All rhinos are close to extinction. In 2004 the International Rhino Foundation (IRF) estimated populations of 11,670 for the white rhino, 3,100 for the black rhino, 2,400 for the Indian rhino, 300 for the Sumatran rhino, and 60 for the Javan rhino. Some individuals are also found in captivity.

Hunting has been the primary cause of rhinoceros decline. Rhinoceros horn is highly prized as an aphrodisiac, as well as an ingredient in Chinese medicine (although its potency has never been shown). Rhinos were first listed by CITES in 1976. This banned international trade in the species and their products. In 1992 CITES also started requiring the destruction of horn caches confiscated from poachers. Nonetheless, people continue to buy and consume rhinoceros horn, and many poachers are willing to risk death to acquire it.

Indian Rhinos

Conservation efforts have improved the status of some rhino species. The Indian rhinoceros, which was reduced to fewer than one hundred individuals in the mid-1970s, has experienced significant population growth in the past twenty-five years. In 2004 the IRF reported some 2,400 Indian rhinos in the wild. Population increase resulted from habitat protection, including the designation of several national parks, as well as measures that curbed poaching.

The Royal Chitwan National Park was established in Nepal in 1973 and includes over 1,000 square kilometers of protected habitat. At the time of establishment, fewer than 80 Indian rhinos were found in the park. Troops from the Royal Nepalese Army were dispatched to help prevent poaching. Indian rhinos flourished at Royal Chitwan, and individuals were later transported to a second rhino conservation area at Royal Bardia National Park, a few hundred miles from Royal Chitwan. In April 2002 the Department of National Parks and Wildlife Conservation in Nepal reported 529 rhinos at Royal Chitwan and 63 at Royal Bardia, a substantial increase from when conservation efforts began.

However, in April 2002 the Department of National Parks and Wildlife Conservation reported that thirty-nine rhinos had died in the past twelve months at Royal Chitwan. Of these, only nine were believed to have died from natural causes. Twenty-five were almost certainly killed by poachers. Horns and other body parts had been removed from the carcasses. Two other rhinos were found electrocuted and three had been poisoned. These were found intact by park officials, who believe that they were killed by villagers whose crops were damaged by rhinos in areas adjacent to the park. The 2002 numbers represent the continuation of a disturbing pattern—forty-two rhinos died in 1999 and twenty-three were killed in 1997–1998.

FIGURE 7.8
The white rhinoceros is native to Africa and can weigh up to 8,000 pounds. (U.S. Fish and Wildlife Service)

African Rhinos

Africa is home to two species of highly imperiled rhinoceros, the black rhino and the white rhino. Both species have a second, smaller horn situated slightly behind the larger main horn. They are threatened primarily by poaching. Wildlife officials in Zimbabwe, Swaziland, and Namibia have gone so far as to sever rhino horns in an effort to curtail poaching. Most experts, however, discourage the practice, as animals use their horns for both digging and defense. In 2004 the IRF reported 3,100 black rhinos in the wild. Of the black rhinoceros subspecies, the northwestern variety is the most severely endangered, with only ten currently found in the wild. Approximately 11,000 white rhinos were reported in 2004. African rhino numbers have risen in recent years, primarily due to improved management as well as private sector and community involvement. Captive breeding efforts for the African rhino species have also met with some success, particularly at the San Diego Wild Animal Park, and may aid in the conservation of these species.