|One of Cleveland Metroparks Zoo's black rhinos|
Contrary to its name, the black rhinoceros (Diceros biocornis) has a thick slate-gray skin, an inch thick at the neck. Black rhinos are the same color as white rhinos. The term "white" actually is a corruption of the Afrikaaner word "weit" meaning wide to describe the wide mouth of white rhinos. The black rhino's mouth is narrower with a prehensile upper lip used for grasping food.
Endangered Animal: Once the most numerous of all rhino species, the black rhino has been the target of the greatest hunting pressure of all. In 1970, the world population of black rhinos was 65,000. By 1980, it dropped to 15,000 and today, it is thought that fewer than 4,000 black rhinos remain. Rhinos are victims of the animal parts trade and have been illegally hunted nearly to extinction.
Vital Stats: Adults weigh between 2,000 and 3,000 pounds and are 10 to 12 feet long. Black rhinos have two horns, one longer than the other. The rhino's horn is made of the same substance as our fingernails and hair. The anterior, or front horn, can grow to 1.6 feet in length in the wild. The black rhino has a good sense of smell and excellent hearing, but very poor eyesight. Their average life span is 40 years.
Disposition: Temperament in this species is unpredictable. Because they see poorly, they can be dangerous when they charge toward a disturbing sound or smell, occasionally even tipping over a vehicle and its occupants.
Rhino Reproduction: Male rhinos reach sexual maturity between 7 and 10 years of age, females between 4 and 7 years of age. Females usually give birth every 3 or 4 years to a single calf weighing close to 100 pounds after a gestation period of approximately 15 months. Black rhinos are very aggressive towards one another during non-estrus periods and mating is often preceded by the female attacking the male.
Rhino Life: Males are solitary. Females are usually found together with a calf and sometimes an older daughter. Territories are marked by spraying urine or by depositing dung piles. Although conflicts arise when strangers move through an occupied area, rhinos are usually tolerant of familiar rhinos in adjacent territories. Rhinos take mud and dust baths to keep cool and discourage biting insects. They feed primarily in the morning and evening on twigs and leaves and especially like to eat thorny vegetation. Their acute sense of smell is their primary method of detecting danger. Puffing snorts and grunts, repeated, signal an alarm call or an angry charge at speeds of up to 35 miles per hour.
Commitment to Save Black Rhinos: The Association of Zoos & Aquariums (AZA) established the black rhino Species Survival Plan (SSP) to optimize reproduction of this endangered species within the protected confines of North American zoos. This is being accomplished through programs of research and on-going animal exchanges. For example, Cleveland Metroparks Zoo's male rhino was transferred from the Cincinnati Zoo and the female arrived from Addo National Elephant Park in South Africa. Studies at this Zoo to correlate black rhino hormone concentrations with their behavior helped predict the best time to introduce the male to the female for mating.