Ceratotherium simum (Burchell, 1817)

Don E. Wilson & Russell A. Mittermeier, 2011, Rhinocerotidae, Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona: Lynx Edicions, pp. 144-181 : 177

1.

White Rhinoceros

Ceratotherium simum

French: Rhinocéros blanc / German: Breitmaulnashorn / Spanish: Rinoceronte blanco

Other common names: Square-lipped Rhinoceros; Northern White Rhinoceros (cottoni); Southern White Rhinoceros (simum)

Taxonomy. Rhinoceros simus Burchell, 1817 ,

South Africa.

The two recognized White Rhino subspecies have in recent historical times had a strikingly discontinous distribution. However, at some stage in the past the species must have occurred in intervening areas, and the presence offossils in Tanzania and a subfossil in Kenya support this assumption. A recent paper based on limited genetic data and morphological differences asserts that the “Northern White Rhino,” subspecies cottoni, should be treated as a separate species. However, this paper has been criticized by other rhino geneticists and rhino conservationists, who argue that much is being made of small differences and that the Northern White Rhino should continue to be treated as a subspecies. Genetically there is a bigger difference between the two White Rhino subspecies than between the Black Rhinoceros ( Diceros bicornis ) subspecies. Two subspecies recognized here.

Subspecies and Distribution.

C.s.simumBurchell,1817—SEAngola,NENamibia,Botswana,Zimbabwe,SMozambique,Swaziland,SouthAfrica,andperhapsformerlyinextremeSWZambia.

C. s. cottoni Lydekker, 1908 — historically present in S Chad, Central African Republic, S Sudan, NE DR Congo, and Uganda;last individuals occurred in DR Congo, but possibly extinct in the wild.

The “Southern White Rhino,” race simum , has been introduced into Kenya, Uganda, and Zambia. Especially vague range map for conservation reasons.

Descriptive notes. Head-body 340-420 cm, tail 50-70 cm, shoulder height 150-180 cm; weight 2300 kg, but ranges from 1350 kg to 3500 kg, with males heavier and larger than females. The White Rhino is the largest of the five species and size dimorphism is greater than in the other four species. The head and body are massive, and a pronounced bump (nuchal hump) on top of its short neck helps support the head. In silhouette, the sacral bump two thirds of the way along the back is much more marked than in the Black Rhino, which tends to have a more curved back profile. The most dramatic features aside from the enormoussize are the large horns and distinct square lip. The anterior horn is normally the larger of the two, and averages 90 cm; the record length is 150 cm. The horns of females are often longer and thinner than those of males, which tend to be shorter and chunkier. The extremely wide mouth is unlike that of other rhinos and lacks the prehensile tip found in other species. Skin color varies from a brownish wash to gray. Body hair is limited to the tips of the ear and tail. The ear shape also differs from that of a Black Rhino.

Habitat. Both the northern and southern subspecies are grazers, so are restricted to grassland and savanna habitats. They also fare poorly in areas subjected to very cold, frosty winters or in very arid areas. The highest densities occur in savannas where soils are reasonably nutrient rich and rainfall levels are intermediate (around 700-800 mm), such as in Hluhluwe-Umfolozi Game Reserve (2-3 ind/km?) in KwaZulu-Natal. However, densities are generally much lower, in the region of 0-1-0-5 ind/km?*.

Food and Feeding. In contrast to the African Black Rhino, the White Rhino is strictly a grazer. The specialized mouth parts—a broad flat lower lip and hard pad—are adaptations for a grazing lifestyle and allow the White Rhino to clip grasses close to the ground. The efficiency with which rhinos graze creates what ecologists term “grazing lawns,” which are also used by other wild herbivores attracted to the nutritious regrowth and to the open areas where predators are more easily detected.

Breeding. Reproductive data are similar to other rhino species. Gestation is 16 months, intercalf interval is 2-3 years on good grazing grounds, and age at first reproduction is about 6-7 years. As with other species, courtship is aggressive and the males pursue females, trying to keep estrous females within their breeding territories.

Activity patterns. The large mass of the White Rhino implies that it must devote a considerable amount of time to feeding to meetits metabolic requirements. White Rhinos spend about half the day grazing, interspersed with resting periods (often on breezy ridge tops or under trees) and wallowing in muddy depressions during the hottest hours of the day. White Rhinos drink daily but can go for several days without drinking.

Movements, Home range and Social organization. White Rhino females are more social than Black Rhino females. They have been sighted in groups of up to 14 individuals, including calves and subadults. Adult males of both species are solitary. As with the Greater One-horned Rhinoceros ( Rhinoceros unicornis ), subadult males may cluster, perhaps to avoid being driven off by dominant males and to gain better access to the best grazing areas. Dominant bulls mark their home ranges by daily patrols of their boundaries, spraying urine, depositing dung in latrines, and making prominent scrapes on the ground. In Garamba National Park, animals ranged over several hundred square kilometers. In south-west Kruger the average range of adult males was 9-9 km*and females 22.8 km? The summer wet season range of females was larger, 21-4 km* compared to 11-6 km? for males. In the Hluhluwe-Umfolozi Game Reserve, core areas for territorial males averaged only 1-7 km?in prime habitat and the average size of female ranges was lower than in Kruger, at 16-2 km®. Dominant bulls try to retain females in estrus that wander through their territories, so the males compete for the home ranges with the best water and grazing, which are mostlikely to attract females. White Rhinos, unlike the Asian rhinos, are poor swimmers and sometimes drown, which explains why major rivers, such as the Zambezi and the Nile, are major dispersal barriers.

Status and Conservation. CITES Appendix I in most countries in its range, and on Appendix II in South Africa and Swaziland. Classified as Near Threatened on The IUCN Red List. The recovery of the Southern White Rhino is widely hailed as the most successful example of international wildlife conservation. By 1885, the number of Southern White Rhinos in what became their last stronghold, the Umfolozi Reserve in what is now part of Hluhluwe-Umfolozi Game Reserve, KwaZulu-Natal, South Africa, had been reduced to around 20-50. Today, more than 20,000 rhinos exist in the wild in more than 430 populations. About 93% ofall free-ranging animals are in South Africa, but over 1000 now occur in the wild outside that country with significant populations in Namibia, Zimbabwe, and Kenya, growing populations in Botswana and Swaziland, and small numbers in Uganda, Mozambique, and Zambia. The populations introduced in Kenya, Uganda, and Zambia, are north of the Zambezi River and outside the historic range of the species. This remarkable effort shows that even very large, slow-reproducing mammals can recover relatively quickly if provided strict protection, enough space, good forage conditions, and active biological management where surplus animals have been translocated to set up new populations. Southern White Rhinos can be bought and sold, and since 1968 there has also been limited sport hunting. This has helped create economic incentivesfor the private sector and more recently for local communities to conserve White Rhinos, and has generated much-needed revenue to help fund their conservation. The successful translocation programs for the Southern White Rhino have inspired similar efforts with the Greater One-horned Rhino in Nepal, and translocations are planned for Assam, India. The Northern White Rhino is classified as Critically Endangered on The IUCN Red List and presents the opposite conservation story. Since 1984, the only confirmed surviving population was in Garamba National Park, DR Congo, where a similarly dedicated group of conservationists and wildlife officials struggled valiantly to recover this population. By then, the number had been reduced to only 15, but under protection the number increased to 30 by 1992. Civil wars and unrest resulted in poaching balancing out births, and by April 2003 there were still 30. However, heavy poaching by large, well-armed gangs of Arabian horsemen from Sudan had reduced the number to only four by August 2005. Since then another carcass was found and systematic efforts to find any remaining individuals or their spoor have been unsuccessful. This population was declared probably extinct in 2009. Thelast four potential breeding individuals in captivity have been moved from Dvur Kralove Zoo in the Czech Republic to a more wild setting in Kenya in the hope that this will stimulate successful breeding. Given the low founder genome equivalent of these “pure” Northern White Rhinos (which are interrelated), conservation biologists have recommended intercrossing these animals with Southern White Rhinos. The hope now lies in conserving as many adaptive Northern White Rhino genesas possible, and eventually, if this is successful, reintroducing animals with these genes into the species’ former range, or, failing that, into suitable secure areas nearits former range.

Bibliography. Alexander & Player (1965), Anonymous (1965, 1970), Allbrook et al. (1958), Buys (2000), Cave (1963, 1969), Cooke (1950), Foster (1967), Groves et al. (2010), Guggisberg (1966), Heinichen (1969), Hillman-Smith (1998), Hooijer (1959), Jordaan (2010), Owen-Smith, N. (1971, 1973, 1975), Owen-Smith, R.N. (1988), Pitman (1955), Player, |. (1967), Player, |. & Feely (1960), Player, R.I.C. (1972), Reynolds (1960), Schomber (1963), Vigne & Martin (2006), Waldram et al. (2008), White et al. (2007).

Figures

1. White Rhinoceros (Ceratotherium simum), 2. Black Rhinoceros (Diceros bicornis), 3. Greater One-horned Rhinoceros (Rhinoceros unicornis), 4. Javan Rhinoceros (Rhinoceros sondaicus), 5. Sumatran Rhinoceros (Dicerorhinus sumatrensis)

Subspecies and Distribution. C.s.simumBurchell,1817—SEAngola,NENamibia,Botswana,Zimbabwe,SMozambique,Swaziland,SouthAfrica,andperhapsformerlyinextremeSWZambia. C. s. cottoni Lydekker, 1908 — historically present in S Chad , Central African Republic , S Sudan , NE DR Congo , and Uganda ;last individuals occurred in DR Congo , but possibly extinct in the wild. The “Southern White Rhino,” race simum , has been introduced into Kenya , Uganda , and Zambia . Especially vague range map for conservation reasons.