Animal Info - Black Rhinoceros

(Other Names: Browse Rhinoceros, Hooked-lipped Rhinoceros, Kifaru, Prehensile-lipped Rhinoceros, Rhinocéros Noir, Rinoceronte Negro)

Diceros bicornis

Status: Critically Endangered

Contents

1. Profile (Picture)
2. Tidbits
3. Status and Trends (IUCN Status, Countries Where Currently Found, Population Estimates, History of Distribution, Threats and Reasons for Decline)
4. Data on Biology and Ecology (Weight, Habitat, Age to Maturity, Gestation Period, Birth Season, Birth Rate, Early Development, Dispersal, Maximum Age, Diet, Behavior (Senses, Activity Patterns, Movement, Attitude), Social Organization (Groups, Relations, Mating), Age and Gender Distribution, Density and Range)
5. References

Profile

Pictures: Black Rhino #1 (13 Kb JPEG) (Intl. Rhino Found. 2002); Black Rhino #2 (19 Kb JPEG) (Czech Web Site); Black Rhino #3 (21 Kb JPEG) (Univ. Alaska Mus.)

The black rhino weighs 800 - 1400 kg (1760 - 3080 lb). Its height varies from 1.3 - 1.8 m (4.3 - 5.9'). The black rhino has 2 horns.  Its skin is dark yellow-brown to dark brown or dark gray. The black rhino occurs in a wide variety of habitats, from desert areas in Namibia to wetter forested areas in the highlands of Kenya, to savannas and bushveld areas where the highest densities of black rhino occur. The black rhino is a browser. It prefers leaves, twigs and branches from small acacia’s and other woody shrubs and small trees as well as herbs and legumes. When the weather is hot, the black rhino drinks water daily and must be within walking distance of water. In cooler temperatures it can go without drinking water for up to 5 days if its food is moist. The black rhino’s eyesight is poor, but its hearing is good. Its sense of smell is well developed and is probably the most important of its senses. 

Although its belligerence has been exaggerated, the black rhino is unpredictable and can be a dangerous animal, sometimes charging a disturbing sound or smell. Black rhinos are predominantly solitary, the most commonly observed groups being lone males or adult females with young. Black rhinos that share a part or all or their range exhibit a familiarity with one another instead of the aggression that they exhibit to total strangers. Although at times several bulls may court a female simultaneously without apparent antagonism, serious fights and frequent deaths result from conflicts between males over estrous females. A premating bond develops between the bull and the cow, and the pair remain together during resting and feeding. They sleep in contact with each other.

The black rhino was formerly found in suitable habitat over most of Africa south of the Sahara, from southwestern Angola across the Cape Province up to East Africa and north, avoiding the Congo Basin and its rain forests, to Somalia and southwestern Ethiopia, then westward along a strip between the Sahara and the Congo and Nigerian forests to the region of Lake Chad. The black rhino population suffered an enormous reduction from a probable several hundred thousand at the start of the 20th century to less than 2,500 by the early 1990s. However, since 1995, black rhino numbers at a continental level have started increasing again. Hunting and clearance of land for settlement and agriculture were the major reasons for the decline of black rhino populations in the 20th century. The situation facing the black rhino is still critical. The demand for rhino horn from Asia (for traditional medicines) and from the Middle East (for dagger handles) persists, and the threat of a return to large-scale poaching is still present. 

Tidbits

*** Africa's two rhino species, the black rhino and the white rhino, are not named for their colors but for the shape of their lips. The black rhino's lips are narrow, and the upper lip is hook-shaped (for browsing leaves). The white rhino's lips are wide and square-shaped (for grazing grass). The Dutch settlers (Boers) of South Africa referred to the rhino with the wide, square-shaped lips with the Dutch word for "wide" - "wijde" to distinguish it from the hooked-lipped rhino. To English-speaking colonists, this sounded like the word "white", and they called it the "white" rhino. Then, to distinguish the other rhino, they called it the "black" rhino.

*** As early as the 8th century AD, Muslim traders were involved in the trade of rhino horn and ivory from the African coast to India and China. Historical sources indicate that demand for rhino horn was significant in the medieval period.

*** In 1990 it was reported that in Guangzhou, China, illegally imported rhino horn sold for US$18,770/kg ($8,530/lb) (Cumming et al. 1990).

*** Black rhinos often have a symbiotic relationship with birds called "oxpeckers" (Buphagus africanus and B. erythrorhynchus). The birds feed on external parasites of the rhinos, and with the birds' more acute eyesight than the rhinos', the birds warn the rhinos of potential danger.

*** Mortal combat between black rhinos, the most recorded for any mammal, results in about 50% of the male black rhinos and 30% of the female black rhinos dying from combat-related wounds (Berger & Cunningham 1998).

*** The record length of a black rhino horn is 1.4 m (4.5') (Nowak 1999).

*** Etymology of the scientific name of the black rhino: the genus name ("Diceros"): "di" = "two" + "ceros" = "horn" (Greek); the species name ("bicornis"): "bi" = "two" + "cornis" = "horn" (Latin) (Intl. Rhino Found. 2005).

Status and Trends

IUCN Status:

[The IUCN (International Union for the Conservation of Nature; also called the World Conservation Union) is the world’s largest conservation organization. Its members include countries, government agencies, and non-governmental organizations.  The IUCN determines the worldwide status of threatened animals and publishes the status in its Red List.]

  • 1960's - 1970's: Vulnerable
  • 1980's - 1994: Endangered
  • 1996 - 2002: Critically Endangered (Criteria: A2abc) 
  • 2004: Critically Endangered (Criteria: A2abc) (Population Trend: Increasing) (IUCN 2004)

Countries Where the Black Rhinoceros Is Currently Found:

2004: Occurs in Cameroon, Kenya, Malawi (re-introduced), Namibia, Rwanda (re-introduced), South Africa (re-introduced), Swaziland (re-introduced), Tanzania and Zimbabwe. It may be extinct in Angola, Botswana, Chad, Mozambique, and Zambia. (IUCN 2004)

Population Estimates:

[Note: This is a long section. You can skip to the next section if you wish.]

[Note: Figures given are for wild populations only.]

History of Distribution:

The black rhino was formerly found in suitable habitat over most of Africa south of the Sahara, including the Cape region in the south, from southwestern Angola across the Cape Province to East Africa, and north, avoiding the Congo Basin and its rain forests, to Somaliland and southwestern Ethiopia, then westward along a strip between the Sahara and the Congo and Nigerian forests to the region of Lake Chad and the French Cameroons. Over this vast area there were localities where rhinos were absent, as along the coast of Kenya and Tanganyika Territory, or, reportedly, between the Chobe and the Zambezi Rivers (IUCN 1966).

The black rhino population suffered an enormous reduction from a probable several hundred thousand at the start of the 20th century, to less than 2,500 by the early 1990s. From 1992-1995 total numbers remained relatively stable, with increases in some countries being cancelled out by declines in others. However, since 1995, black rhino numbers at a continental level have started increasing again. Many remaining black rhino are now concentrated in fenced sanctuaries and rhino conservation areas where law enforcement efforts can be concentrated at effective levels. Surplus animals have been translocated to set up new populations. Four countries (Kenya, Namibia, South Africa and Zimbabwe) contain the vast majority (97.6%) of remaining wild black rhino. (IUCN 2004)

Distribution Map (50 Kb JPEG) (Intl. Rhino Found. 2004)

Threats and Reasons for Decline:

Hunting and clearance of land for settlement and agriculture were the major reasons for the decline of black rhino populations in the 20th century. In areas where colonial settlement occurred, the presence of the aggressive black rhino was considered unacceptable and in many areas it was systematically exterminated. It was also exterminated in tsetse fly control operations. Hunting for meat, hides and sport, and especially for the rhino's horn, was a major cause of decline, particularly after the introduction of modern firearms. In the last several decades of the 20th century, killing of rhinos to obtain the horn was been the predominant cause of rhino mortality. In addition to the decline in numbers, populations were increasingly fragmented. In 1986, about 75% of 60 discrete populations reviewed comprised less than 50 animals. (IUCN 1966, Curry-Lindahl 1972, Cumming et al. 1990, IUCN 2004) 

The situation facing the black rhino is still critical. The international rhino horn trade ban and the domestic bans imposed in most traditional user countries have driven the trade further ‘underground,’ in some cases inflating prices and making illegal dealing even more lucrative. The demand for horn from Asia (for traditional medicines) and from the Middle East (for dagger handles) persists and the threat of a return to large-scale poaching is still present. Wars, civil unrest, poverty, influxes of refugees, and corruption on the part of some officials within countries where black rhino are found combine so that poachers can escape arrest and poverty-stricken people may become poachers to survive. (Emslie & Brooks 1999) 

Data on Biology and Ecology

Weight:

Adult black rhinos weigh 800 - 1400 kg (1760 - 3080 lb) (Nowak 1999). The size of the black rhino varies from one location in Africa to another.  For example: averages of 855 kg (1881 lb) for 8 males and 887 kg (1951 lb) for 6 females from Hluhluwe (South Africa), and averages of 1124 kg (2473 lb) for 11 males and 1081 kg (2378 lb) for 5 females from Kenya (Hillman-Smith & Groves 1994).  

The height of the black rhino varies from 1.32 - 1.80 m (4.33 - 5.90') (Hillman-Smith & Groves 1994).

Habitat:

The black rhino occurs in a wide variety of habitats, from desert areas in Namibia to wetter forested areas in the highlands of Kenya, to savannas and succulent valley bushveld areas where the highest densities of black rhino occur. It is found mainly in the transitional zone between grassland and forest, generally in thick thornbush or acacia scrub but also in more open country. It is not primarily a grassland or closed-canopy forest animal but favors the edges of thickets and extensive areas of short woody growth. It is generally restricted to habitat within about 25 km (16 mi) of permanent water. (Kingdon 1997, Nowak 1999, IUCN 2004)

The black rhino is found in both the Horn of Africa, Maputaland-Pondoland-Albany, Cape Floristic Region, Succulent Karoo, and Coastal Forests of Eastern Africa Biodiversity Hotspots (Cons. Intl. 2005) and the East African Acacia Savannas Global 200 Ecoregion. (Olson & Dinerstein 1998, Olson & Dinerstein 1999)

Age to Maturity:

Age at first mating in captive black rhinos varies from 4.5 - 9 years, but age at first fertile mating is from 6 - 9 years. In the wild, ages of first conception vary between populations, tending to increase in high density populations, or under poor conditions: 3.8 - 5.7 years in East Africa; 3.5 - 4 years in Zimbabwe; from 3 years 10 months - 9 years 1 month in the high density (introduced) population in Addo National Park, South Africa. Age at first birth was 6.5 years in a low-density population in Umfolozi Reserve, South Africa, and 12 years in a high-density population in the neighboring Hluhluwe Reserve, South Africa. Even though they are capable of reproduction, young males do not breed until they gain a territory or dominant status, usually when they are about 10 years old. (Hillman-Smith & Groves 1994, Kingdon 1997, Rachlow & Berger 1998) 

Gestation Period:

419 - 478 days (14 - 16 months) (Nowak 1999).

Birth Season:

Breeding apparently occurs throughout the year, although some investigators have indicated that there may be mating peaks in Kenya during September - November and March - April, and peaks in Zululand (South Africa) during October - November and April - July. These and other reports suggest that births tend to take place in the rainy season. (Nowak 1999) 

Birth Rate:

A single calf is born at intervals of 2.5 - 4 years (Intl. Rhino Found. 2005). Inter-birth intervals vary between different black rhino populations, tending to increase in high density populations, or under poor conditions (Hillman-Smith & Groves 1994). 

Data on fecundity rates for black rhino populations [for each pair of numbers, the first number = calves/female/year; the second number = calves/population/year] (Milner-Gulland 1999): 

  • Addo (South Africa): 0.46 calves/female/year (1977) 
  • Amboseli (Kenya): 0.25/0.068 (1972) 
  • Corridor: 0.28/0.098 (1983) 
  • Hluhluwe (South Africa): 0.19/0.074 (1983) 
  • Luangwa (Zambia): 0.17/0.046 (1985).
  • Ngorongoro (Tanzania): 0.25/0.068 (1967), 0.24/0.107 (1981)
  • Olduvai (Tanzania): 0.26/0.068 (1967) 
  • Tsavo (Kenya): 0.30 calves/female/year (1970) 
  • Umfolozi (South Africa): 0.33/0.099 (1983) 

Early Development:

A black rhino calf is mobile soon after birth and begins browsing vegetation before it is 1 month old. It first drinks water after 4 - 5 months. (Kingdon 1997)  Weaning is completed after about 2 years (Nowak 1999).

The bond between a mother black rhino and her calf is strong, and the calf lies or feeds close to its mother (Hillman-Smith & Groves 1994).

Dispersal:

A young black rhino usually is forced to leave its mother after 2 or 3 years when the mother has another calf, or sometimes when she is mated. The young rhino may, however, later rejoin its mother for temporary periods of association, especially if it is a female. (Hillman-Smith & Groves 1994)

Maximum Age:

30 - 35 years in the wild (Intl. Rhino Found. 2005); 45 years and 10 months in captivity (Nowak 1999).

Diet:

The black rhino is a browser. It prefers leaves, twigs and branches from small acacia’s and other palatable woody shrubs and small trees as well as palatable herbs and legumes. However, because of high levels of secondary plant chemicals, much woody plant browse (especially many evergreen species) in some areas is unpalatable for black rhinos and is avoided. Succulent plants are often selected in the dry season. Salt licks are visited regularly. (Hillman-Smith & Groves 1994, Kingdon 1997, IUCN 2004) 

In feeding trials, adult food intake averaged 23.6 kg (52 lb) of mixed browse/day. (Hillman-Smith & Groves 1994) 

The black rhino’s semi-prehensile upper lip is used to twist twigs while feeding. The usual feeding height is 0 - 1 m (0 - 3.3'), though a black rhino can reach higher than 2 m (6.6'). Small trees are sometimes pushed down by walking over them to make high branches accessible. Diameters of twigs bitten off are mainly 3 - 10 mm (0.1 - 0.4"), but they could be more than 30 mm (1.2"). This gives a high proportion of woody to green material in the black rhino’s diet. (Hillman-Smith & Groves 1994) 

When the weather is hot, the black rhino drinks water daily and must be within walking distance of water. In cooler temperatures it can go without drinking water for up to 5 days if its food is moist. In arid areas, the black rhino also can go without water for several days, obtaining moisture from succulent plants. However, it is unable to survive extreme droughts. (Hillman-Smith & Groves 1994, Kingdon 1997) 

Behavior:

Senses: The black rhino’s eyesight is poor. It has been estimated that its effective eyesight extends 25 - 30 m (82 - 98‘). The black rhino’s hearing is good. Its sense of smell is well developed and is probably the most important of the senses, although its use is limited by wind direction. Human scent by itself causes great alarm to a black rhino. On the other hand, if it detects no scent, a black rhino will show no interest in a motionless person or car unless it is closer than 20 - 30 m (66 - 98‘). (Hillman-Smith & Groves 1994, Nowak 1999)

Activity Patterns: Black rhinos are more active - feeding, drinking and walking - in early morning and late afternoon to evening. In the middle of the day, black rhinos are mostly inactive (sleeping or standing). The black rhinos are also usually active at night, often feeding, drinking, and walking outside their core areas and in more open habitat than during the day. (Hillman-Smith & Groves 1994)

Movement: Normal movement of the black rhino is at the rate of around 3 - 4 kph (1.9 - 2.5 mph), but in a charge it can reach a speed of 50 kph (31 mph) (Nowak 1999).

Attitude: Although its belligerence has been exaggerated, the black rhino is unpredictable and can be a dangerous animal, sometimes charging a disturbing sound or smell. It has tossed people in the air with the front horn and regularly charges vehicles and campfires. If a black rhino catches the scent of humans, it usually runs away, sometimes for quite a distance before stopping. (Nowak 1999)

Social Organization:

Groups: Black rhinos are predominantly solitary, the most commonly observed groups being lone males or adult females with young. Other groups of various ages and genders occur, but they usually are temporary. The largest temporary group reported in one study included 13 black rhinos. Females usually are found together with a calf and sometimes an older daughter. Females without young may temporarily join a neighboring female. Subadults frequently associate with other black rhinos. Only fully adult males become solitary, and even they may form temporary groups that move and feed together. (Hillman-Smith & Groves 1994, Kingdon 1997, Nowak 1999)

Relations: Black rhinos that share a part or all or their range exhibit a familiarity with one another instead of the aggression that they exhibit to total strangers. Overt territorial behavior is very variable. Adult females have overlapping home ranges. Females in high-density areas are well acquainted with, and generally tolerant of, their neighbors (except in the presence of an estrous female). Two females usually approach each other cautiously, but with little aggression. On contact they may nudge one another with the sides of the head or horn, then usually walk away. On the other hand, the meeting of a male with a female or another male is more likely to be accompanied by aggression, with a stiff-legged, short-step approach, snorting and occasionally head sweeping or horn pushing.  Aggression between males can be violent. However, except during conflicts over estrous females, usually the subordinate or the visitor to a territory retreats. Males in low-density areas meet less frequently and are more likely to be aggressive. (Hillman-Smith & Groves 1994, Kingdon 1997, Nowak 1999, Intl. Rhino Found. 2005)

Mating: An adult male and female, with the female’s young if she has one, form temporary associations for mating during the female’s estrus. A premating bond develops between the bull and the cow, and the pair remain together during resting and feeding. They even sleep in contact with each other. Especially at mating, young are sometimes attacked by males. Although at times several bulls may court a female simultaneously without apparent antagonism, serious fights and frequent deaths result from conflicts over estrous females. (Hillman-Smith & Groves 1994, Nowak 1999)

Age and Gender Distribution:

One study found ratios of adult females to young in Ngorongoro (Tanzania) of 1.0:0.72 and in Olduvai (Tanzania) of 1.0:0.79 (Hillman-Smith & Groves 1994).

The ratio of males to females varies among populations, but overall it is close to 1:1 when all age classes are combined (Hillman-Smith & Groves 1994). 

Density and Range:

Density: The following densities of black rhinos have been reported:

Home range: The following home ranges of black rhinos have  been reported:

  • Mara (Kenya): 5.6 - 22.7 sq km (2.2 - 8.7 sq mi) (Hillman-Smith & Groves 1994)
  • Namib Desert (Namibia): males - 730 ± 210 sq km (1900 ± 540 sq mi); females - 540 ± 160 sq km (1400 ± 420 sq mi). (Berger 1997).
  • Ngorongoro (Tanzania) (average ranges): adult males - 15.6 sq km (6.0 sq mi), adult females - 14.9 sq km (5.7 sq mi) (overall variation in ranges for adult males and adult females: 2.6 - 44.0 sq km (1.0 - 16.9 sq mi)), immature males - 35.9 sq km (13.8 sq mi), and immature females - 27.4 sq km (10.5 sq mi) (Hillman-Smith & Groves 1994)
  • Olduvai (Tanzania) (average ranges): males - 21.8 sq km (8.4 sq mi); females: 35.1 sq km (13.5 sq mi) (overall variation in ranges for adult males and adult females: (3.6 - 90.0 sq km (1.4 - 34.6 sq mi)) (Hillman-Smith & Groves 1994)
  • Serengeti (Tanzania): 43 - 133 sq km (16.5 - 51.2 sq mi) (Hillman-Smith & Groves 1994)

References

Abigail Smigel, Ansell 1969, Berger 1997, Berger & Cunningham 1998, Brooks & Emslie 1997, Burton & Pearson 1987, Cumming et al. 1990, Curry-Lindahl 1972, Czech Web Site, Emslie 2002, Emslie 2004, Emslie & Brooks 1999, Focus 1995, Focus 1997, Focus 1998, Focus 2000b, Focus 2004d, Hillman & Martin 1979, Hillman-Smith & Groves 1994, Intl. Rhino Found. 2002, Intl. Rhino Found. 2004, Intl. Rhino Found. 2005, IRF 1996, IUCN 1966, IUCN 1994, IUCN 1996, IUCN 2000, IUCN 2003a, IUCN 2004, Kerr & Fothergill 1971, Kingdon 1997, Largen & Yalden 1987, Macdonald 1984, Milner-Gulland 1999, Morgan-Davies 2001, Muruthi et al. 2000, Nowak 1999, Olson & Dinerstein 1998, Olson & Dinerstein 1999, Oryx 1965a, Oryx 1978d, Oryx 1980d, Oryx 1982, Oryx 1988c, Oryx 1990b, Oryx 1991d, Oryx 1992, Oryx 1994b, Oryx 1995j, Rachlow & Berger 1998, Roth 1967, Silva & Downing 1994, Univ. Alaska Mus., Varisco 1989

Top of Page | Search This Site

Home | Rarest Mammals | Species Index | Species Groups Index | Country Index | Links

Last modified: March 11, 2006;

© 1999 - 2019 Animal Info. Endangered animals of the world.  Contact Us..