The Black Rhino - An example of a monotypic species
The rhinoceros is one of the most endangered species of animals in the world. There are now processes in place in protecting endangered animals and it is to be hoped that these safeguards have not come too late.
There are five species of rhinoceros still managing to live on this earth; two are African and three are Asian. The two African species and one of the Asian species belong to monotypic species, meaning they are the only examples of their genus. Other examples of monotypic species are the edible dormouse, red panda, numbat and pronghorn.
If these animals become extinct, the genus to which they belong will disappear forever.
The two types of African rhinoceros have the common names of 'black rhino' and 'white rhino'. The black rhino isn't actually black nor is the white rhino white! The black rhino is grey but often appears darker depending on the colour of the mud in which it has been wallowing. It is believed the 'black rhino' tag was given to differentiate it from the white rhino, which is actually a slatey grey.Credit: Wikimedia
Apart from the colour, the black rhino differs in that it has a prehensile, pointed upper lip. It is also known as the hook-lipped rhino. The white rhino has a broad mouth and the additional common name of wide-lipped rhino.
The scientific name of the black rhino is Diceros bicornis and it is the only living representative of the genus Diceros. 'Dicero' comes from the Greek di (two) and ceros (horn). 'Bicornis' comes from the Latin bi (two) and cornis (horn). This must make it a 'two-horn two-horn'!
There are four subspecies of black rhinoceros. The south-western black (D.b.bicornis) is classed as Vulnerable, the western black (D.b.longipes), eastern black (D.b.michaeli) and south-central black (D.b.minor) are all classed as Critically Endangered. As a whole, they are classified as Critically Endangered on the IUCN Red List.
The subspecies are differentiated mainly by geographical regions. In 1995, Kenya has 88% of the Eastern African subspecies Diceros bicornis michaeli. Research is continuing into 'fingerprinting' the horn of rhinos, as each rhino horn has unique qualities. This would enable officials to determine the area, the family group and perhaps even its diet. Such information would help in determining from what area a rhino was poached.
Both African species have two horns which are made of clumped fibrous material, rather than bone. The front (anterior) horn is the longer and may be 0.5 to 1.3 metres in length. The rear (posterior) horn is smaller and up to 55cm long.
The black rhinoceros is the smaller of the two species and reaches 1.6 metres at the shoulder and weighs between 900 and 1,350 kilograms. It holds its head higher and can be very aggressive. It makes up for poor eyesight with a good sense of smell and very acute hearing. When running, it holds the tail erect. The range of vocal sounds is wide, possibly with some sounds below the range of human hearing.
The prehensile lip is used to grasp leaves and twigs of woody plants and herbs. Most feeding is done in the cooler hours around dawn and dusk. They rest in the shade or wallow in mud holes through the heat of the day. The mud serves to keep the skin from drying out in the harsh sun. It also deters biting insects.
The rhinoceros defecates in piles along its walkways. It then scatters the dung with the hind legs. The dung is woody and fibrous in texture. To urinate, it sprays backwards against vegetation and then kicks backwards, often destroying the vegetation by its actions. This is a form of communicating and is also practised by females when ready to mate. Males 'spray-kick' most of the time but more frequently when courting a female.
The black rhino is mainly solitary but their home ranges overlap. It is a long-lived species. Females are sexually mature at around five to seven years old and calve every two to four years. The gestation period is 16 months and a single calf is born. Calving takes place at any time of the year and the calf generally remains with the mother until a new calf comes along. Rhinos are inquisitive and often aggressive with humans and other animals.
The black rhino can reach speeds of up to 45kph for short periods. It is usually found in thickets, browsing and grazing on long grass, shrubs, twigs and leaves. It has no trouble dealing with thorns in its dinner!
Although the black rhino was once much more widespread, its range is now restricted to fragmented areas mostly in game reserves, in Swaziland, Malawi, South Africa, Cameroon, Zimbabwe, Namibia, Kenya and Tanzania. It frequents a range of habitats from the deserts of Namibia through wooded grasslands, broadleaved woodlands and acacia savannahs.
Because of its aggressive nature and the publicity given to the international conservation drive for its protection, the black rhino is possibly the best known of the live rhinoceros species.
In the 1970s, there was an estimated 20,000 black rhino in Kenya. By 1982, poaching had reduced the number to less than 400. Numbers have been stabilised but the poaching has not really been stopped. Loss of habitat is also an ongoing problem for the black rhino.
Rhino horn is valued in Chinese traditional medicine.Credit: Wikimedia - Author Jialiang Gao www.peace-on-earth.org
It is also used for handles of curved daggers or ‘jambiya (jambia)’, traditionally presented to young boys of 12. Demand exploded in the 1970s as the oil-rich Gulf States could suddenly afford high prices for the horn. It is estimated that roughly 96% of the total number of black rhinos was lost between 1970 and 1992.
A number of steps have been taken to try to halt the decimation of the animal. Rigorous protection within fenced sanctuaries has probably been the most successful innovation. Private sectors and States have co-operated and formed partnerships in some areas. Some unfenced areas within a larger area have been strongly protected. Dehorning has been another innovative step taken by some countries to reduce the incentive to poach.
A major step forward occurred when Yemen came on board the Convention on International Trade in Endangered Species (CITES), causing a drop in demand in the Middle East. By 2001, the black rhino population was back to 3,100. In six of the eight range states, numbers are increasing, mostly in areas where the animals are heavily protected. Advice is provided by the African Rhino Specialist Group of the World Conservation Union (IUCN) on the conservation of the rhino and a detailed Action Plan has been drawn up. This gives strategic direction and wide-ranging information on the necessary steps for conservation of one of the world's largest and most fascinating creatures.