Black Rhinoceros

BLACK BEAUTY?

"He is a swinish, cross-grained, ill-favoured, wallowing brute, with a hide like a rasp, an impudent cock of the chin, a roguish leer from out the corner of his eye, a mud begrimmed exterior and a necklace of ticks and horse-flies!"

A none-too-complimentary profile by trophy hunter Captain W. Cornwallis Harris, 1840.

The Black Rhinoceros has a hooked, prehensile nose, carrying its head high on its shoulders, as opposed to the low-hanging head and hump-shoulders of its relative, the grazing White Rhino. Predominantly a browser of short woody trees and shrubs, the Black Rhinoceros uses its pointed upper lip to grasp leaves and twigs, employing its double horns to dig roots or break branches too far out of reach. Its grey, wrinkled skin varies in colour due to the mud and dust in which it frequently wallows to cool down and protect against flies and sun. The two species of African rhino are similar in height, averaging about 1.6m at the shoulder, but the Black Rhinoceros has roughly half the mass of a White Rhinoceros, weighing in at a demure 1000 kg.

Territory and Communication

Rhinoceros live in established territories but are tolerant of neighbours and share overlapping ranges and watering holes with few confrontations. Their preferred habitat is found along the edges of thickets and areas of low woody growth. Since Black Rhinoceros sweat to reduce their body temperature, their ranges do not tend to extend beyond 25 km from a daily supply of water. Home ranges are criss-crossed by frequently used trails, marked by both sexes with dung middens. Dunging is a social behaviour, and serves as a form of communication as well as means of personal declaration. The animals will defecate, frequently spreading the deposits or wiping their hind legs through the accumulated dung pile as a means of spreading their scent.

Males also tend to mark their territory with urine, using their recurved penis to spray grass, stumps and rocks. Several males may peaceably share territory, although there is usually a dominance hierarchy. Confrontation between Black Rhinos generally occurs between males competing over cows in oestrus, or when a nomadic animal enters an already populated area. }

Courtship and Maternal Bonds

Black Rhinoceros males tend to be solitary while females typically are found with their current offspring. Or, if there are no young, cows may develop attachments with other sub-adult rhinos. The maternal bond is only broken when the cow is ready to give birth to a new calf, and the young adult is driven off to make its own way in the world. Births are about two to four years apart and occur at all times of the year with gestation lasting anywhere from 446-478 days (15 months). Lion and Spotted Hyena are known to prey on the calves, and individuals with deformed tails or ears bear evidence of close encounters in the past.

Males only associate closely with females while they are in oestrus. Courtship is very businesslike, with the bull making pseudo-aggressive postures towards the female, with typical foot scraping and urine spraying. The male circles the female, curling his upper lip, and nudging her flanks with this horns. He then mounts the female from behind. Copulation may last up to half an hour, and is repeated at intervals over several days.

Endangered

Poaching and loss of habitat have decimated the Black Rhinoceros population, leaving only small populations in protected areas of Namibia, Kenya, Zimbabwe, Tanzania and South Africa. The existence of these endangered pachyderms in Mozambique, Angola and parts of West Africa is unconfirmed. Use of the horns, which consist of keratin (the same substance in human fingernails), in traditional Eastern rituals and ceremonies has led to massive demand for an ever increasing commodity. From an estimated population of 60,000 in 1970, their numbers crashed to less than 2,000 in 1997. Careful management and protection provide the best chances for the species' survival.

Posted: Mammals by CC Africa, Date: 6 October 2006