Black Rhino, Diceros bicornis
2003; minor update 2012
TAXONOMY & NOMENCLATURE
(Amato et al., 1993) (du Toit, 1987) (Emslie & Brooks, 1999)
(IRF, 2002) (Kuzmin 2009) (Prothero, 1993) (Prothero et al. 1986)
(Steiner & Ryder 2011) (Rookmaaker, 1995)
Describer (Date): Linnaeus 1758 (Diceros bicornis)
Suborder: Ceratomorpha (rhinos and tapirs)
Genus: Ceratotherium (white rhinos)
Genus: Dicerorhinus (Sumatran rhinos)
Genus: Rhinoceros (Javan and Indian rhinos)
Species: Diceros bicornis (black rhino)
Subspecies/Ecotypes: D. b. longipes (western black rhino)
D. b. michaeli (eastern black rhino)
D. b. bicornis (southwestern black rhino)
D. b. minor (south central black rhino)
- Some disagreement still exists regarding subspecies or
"ecotypes" (see du Toit, 1987, and Rookmaaker,
- To simplify communication, the African Rhino Workshop in
Cincinnati (1986) proposed four groupings, knowing that they
were not necessarily subspecifically different. However many
researchers refer to these as subspecies (Rookmaaker, 1998).
- Amato et al. (1993) did not find significant genetic
differences between the groups.
- Source for subspecific nomenclature above: IUCN African Rhino
Specialist Group (see Emslie and Brooks, 1999).
- Probably called Black Rhinoceros to differentiate it from the White
Rhinoceros. It is likely that "white" is a misunderstanding
of the Afrikaans word "weit" (wide, as in
"wide-lipped"). Skin coloration between the two species is
- Other common names for black rhino: browse rhino, prehensile-lipped,
hook-lipped, rhinoceros noir (Fr.), Spitzmaulnashorn (Gr.), Faru
- Closest living relative: tapirs
- Evolutionary history
- Perissodactyls (odd-toed hoofed mammals) first appear in the fossil record around around 58 million years ago (upper Paleocene)
- Over the last 50 million years,
rhinocerotids became extremely diverse ecologically, and various
species were distributed throughout the
- Earliest known rhino-and horse-like ancestor: Hyrachyus (Superfamily:
Rhinocerotidae), is found in Wyoming, Europe, Canadian Arctic, and
possibly Asia; middle Eocene; the size of a large dog, with hooves,
herbivorous teeth, but hornless.(Prothero et al. 1986)
- Indian rhinoceroses first appeared around 26 million years ago (late Oligocene) (Steiner & Ryder 2011)
- Summatran rhinoceroses had evolved by 25 million years ago (late Oligocene) (Steiner & Ryder 2011)
- The black and white rhinoceroses of Africa didn't evolve until around 17 million years ago (early Miocene) (Steiner & Ryder 2011)
- By around 7 million years ago (Miocene) black and white rhinos became distinct genetically (Brown & Houlden 2000)
- Once widespread in North America, died out there about 4
million years ago.
- Extinct Woolly Rhino (hairy, with flattened saber-like horn)
lived in Eurasia during the ice age and became extinct around 12,000 years ago (Late Pleistocene) (Kuzmin 2009); some specimens have been found frozen in permafrost
and preserved in peat bogs.
- Oldest modern rhino lineage: Indian rhinos with their single horns (Steiner & Ryder 2011)
DISTRIBUTION & HABITAT
(Emslie & Brooks, 1999)
- Previously distributed widely in sub-Saharan Africa; everywhere except
extremely mesic and xeric areas.
- Presently occurs only in small isolated pockets in sub-Saharan Africa
- D. b. longipes (western): Historical- savannahs of central
western Africa. Present- Cameroon
- D. b. michaeli (eastern): Historical- S Sudan, Ethiopia,
and Somalia, through Kenya to N central Tanzania. Present- Mostly
Kenya; small numbers in Rwanda and Tanzania, and a game reserve
in South Africa (well outside its range).
- D. b. bicornis (southwestern): Historical- Namibia, S
Angola, W Botswana, and SW South Africa. Present- Most in deserts
and arid savannahs of Namibia; reintroduced populations in South
Africa and other parts of Namibia; possibly a few in Angola.
- D. b. minor (south central): Historical- W, S Tanzania
through Zambia, Zimbabwe and Mozambique to N and E South Africa.
Present- Mostly in South Africa (stronghold) and Zimbabwe; fewer
in Swaziland, S Tanzania, and Mozambique.
Historic and present distribution, from Intl
Distribution of subspecies,
from (Emslie & Brooks, 1999)
- Savannahs with a high diversity of woody shrubs and herbaceous plants.
- Not found in closed canopy forests or open grasslands
(Emslie & Brooks, 1999)(Kingdon, 1997)
Body Weight: 1,000 - 1,800 kg (2200 - 3970 lbs)
Body Length (head/body): 2.9 - 3.75 m (114-148 in.)
Tail Length: 60 - 70 cm (24 - 28 in.)
Shoulder Height: 1.4 - 1.8 m (55 - 71 in.)
- Very thick, gray skin with deep folds; heavy, stocky body; short neck,
large head; almost hairless; Three hooved toes, central toe is largest
and takes most of the weight; small tail with tuft of hair at the tip.
- Large, robust cheek teeth; no canines or incisors
- Skin color often obscured by dirt due to wallowing in mud or dust.
- Two horns on the rostrum, one in front of the other.
- Made of keratin (like true horns)
- No bony core; not attached to skull; not shed
- Species level differences:
- Black: Two horns, skin hairless, no incisors, low-crowned
lip triangular-shaped and prehensile.
- White: Two horns, skin hairless, no incisors, high crowned
lip square shaped and not prehensile, large hump behind head,
- Indian: One horn, skin hairless, tusk-like lower incisors,
high crowned molars, prehensile upper lip, skin forms heavy folds
like armor plating, posterior of neck plate continuous, large
bumps on skin of shoulder, upper arms and upper legs.
- Javan: One horn which is only horny knob in female, skin
hairless, tusk-like lower incisors, low-crowned molars,
prehensile upper lip, skin forms heavy folds like armor plating,
posterior of neck plate separated, skin with mosaic-like pattern
rather than large bumps.
- Sumatran: Two horns which are very small in the female,
skin hairy, lower incisors present but not tusk-like, prehensile
upper lip, skin fold forming only a few divisions, no folds near
nose. Smallest species.
- Subspecific differences: D. b. michaeli has longer, thinner,
more curved horn, and is more aggressive. D. b. bicornis is larger,
has a straighter horn, and is adapted to a more arid habitat.
Other Physical Characteristics
- It can be difficult to tell males from females
- Older females have more of a sway-back, presumably due to carrying
heavy calves during various pregnancies.
- Male with backward facing genitalia (as in hippo)
- Males w/o scrotum (testes abdominal)
- Female with two teats
- Poor eyesight
- Good sense of smell and hearing
BEHAVIOR & ECOLOGY
(Estes, 1991)(Goddard, 1967)(Merz, 1991)(Schenkel & Schenkel-Hulliger, 1969)
- Active both day and night
- Field observations in Kenya show the following general daily activity
- Most inactive between 10:00 AM and 3:00 PM, the hottest part
of the day.
- Most feeding occurs in the hours before and after this
- Most watering activity (traveling to and drinking water) was
observed between 3:00 and sundown.
- Specific activity patterns (involving time, location, and
activity) vary among individuals, and among consecutive days
for a single individual.
- Rest in the shade and wallow in shallow mud pools during the
heat of the day. In Tanzania, 90% of wallowing occurred
between 4:00 and 6:00 PM (Goddard, 1967).
- Sometimes rests and sleeps in shallow water.
- Will wallow in dust if mud is not available.
- Wallowing helps reduce the animal's body temperature (mud and
water), and protects against ectoparasites (dust).
- Most of the time rests/sleeps laying down, but sometimes while
- Do not form organized social groups, but individuals often congregate
in small groups for short periods.
- Females with young tend not to socialize with other adults, and may
form the only stable associations.
- Adult males socialize the least, but do occasionally tolerate the
presence of others.
- Merz (1991) observed individual treatment by a dominant male towards
each of five females during mating, suggesting a more complex social
interaction than was previously thought.
- Little information exists in the literature regarding social dominance.
- Level of territoriality (defending a specific patch of ground)
is unclear. Territorial behavior has been described as (1)
territorial, (2) territorial, but shared trails that may bisect one or
more territories, (3) not territorial.
- Territorial size of radio-tracked black rhino in Natal: males
3.9 to 4.7 km2; females 5.8 to 7.7 km2.
- Merz (1991) describes preferred day time resting spots or "houses"
that are frequently revisited .
- Some are shared by several individuals, some are used only by one
- Tend to be on high ground
- Individuals tend to lie facing downwind; often align themselves
with the shadow of a large horizontal branch (if present) for
- Home range (undefended area where an animal ranges in search of
- Size varies (seasonally, and between different habitat types)
and depends on resource availability.
- In habitats with an abundance of food and water, home ranges
tend to be smaller, and rhino density tends to be higher.
- Home ranges of individuals often overlap, and neighbors tend
to tolerate each other without aggression.
- Home range size: 2.6 to 44 km2
in Ngorongoro, and 43 to 133 km2
in the Serengeti.
- Overall, little aggression is shown towards one another, but encounters
of "bluff and bluster" are not
- Aggressive encounters
- Male to male: Fight occasionally (horn-jousting,
head-pushing) or exhibit a threat reaction. Males have also been
observed feeding and traveling together. However, most of the
time they avoid each other.
- Female to Female: Do not generally act aggressively toward
one another. Aggressive encounters are short and often involve
facing one another and pushing head to head.
- Male and Female: Usually occurs prior to mating.
"Bluff and bluster" displays may last for hours.
- Tail up: alarm, curiosity; female receptivity (tail crooked)
- Ears straight up: interested, curious
- Ears flat, sometimes with wrinkled nose and grimace: anger
- Eyes not very expressive
- "Bluff and bluster": Upon meeting
another individual, one rhino snorts and swings head side-to-side in a
threatening manner, but will gallop away (swinging back around, often
repeating this behavior) if the other rhino lunges forward.
- "Complex bull ceremony" described by Schenkel &
Schenkel-Hulliger (1969); occurs when male is alone, or when female
nearby; not always in this order or including all elements; probably
"symbolized aggression" toward a potential rival.
- Sniffing a bush
- Snorting in attack posture
- Bashing bush with rostrum and horn; forceful, side to side
movement of head
- Trampling bush and scraping with hind feet
- Urinating in bursts over plant
- Merz (1991) observed several types of vocalizations in black rhinos:
- Lion-like growl and elephant-like trumpet (heard during a
- Long snort (anger)
- Short snort, like a sneeze (alarm)
- Short snort with pricked ears and wrinkled nostrils (startle
reaction to newcomer)
- "High-pitched wonk" (fear)
- High-pitched scream (terror)
- "Mmwonk", a deep, resonant sound (contentment)
- Squeak, done with different tones and intonations can mean
"I'm lost", "Where are you?", "I'm
over here", and other emotions that are not yet
- Breathing (long and slow, or short and quick) can be used to
communicate greetings, anxiety, and reassurance.
- "Puffing snort" is a common greeting when males and females
encounter one another (Goddard, 1967).
- In contrast, vocal communication in white rhinos seems much less
- Sent marking is a very important method of communication in rhinos
because of their poor eyesight and more solitary nature.
- Urine spraying
- Males and females mark bushes or dung piles with a backwards,
horizontal spray of urine.
- Both can shoot up to 3 to 4 meters.
- Females do this most often when they are in season,
spraying in short bursts.
- A male may come and spray over a female's scent marking.
- Spraying also occurs along feeding or watering tracks.
- Different than regular urination, and is used in
- Dung Piles:
- Often defecate in the same place repeatedly
(="lavatories") along feeding tracks, near water
sources, and scattered randomly throughout the home range.
- "Calling cards": When approaching the dung pile of
another individual, a rhino may just sniff, or add to the pile
(defecate and scrape). Smelling the dung piles may be a way for
rhinos to identify each other.
- Scent trails: dragging the hind feet after defecation enables a
rhino to leave a scent trail as it walks through its home range,
assisting with orientation. Other individuals may follow the
- Often, two individuals traveling together defecate in the same
spot (one after the other) or at the same time. This happens with
a mother and her young, as well as with two adults.
- Female receptivity: females tend to scrape more vigorously when
- Courtship: Sometimes a male follows a receptive female and scrapes
her dung vigorously (flinging it far away) every time she
defecates. This makes it more difficult for other males to follow
- Head rubbing: against trunk or stump may be method of scent
marking; horn rubbing less common.
- Making Flehman: mostly done by male when sniffing rear end or
urine mark of receptive female. Flehmen is a German word describing
characteristic behavior- lip curl, nose wrinkle, and head lift. It is
thought to aid in bringing scent to the Jacobson's organ (also called
vomeronasal organ), located far back in the palate, which detects
trace quantities of chemicals in the air (i.e., pheromones).
- In Kenya, rhinos and elephants follow wide trails (several km long),
with little vegetation, that go between water and feeding areas. A
smaller network of trails, usually not used by elephants, is shared
with other wildlife, and used for during foraging (Schenkel &
- Rhinos tend to be fairly sedentary. Because of this, they tend not to
disperse very rapidly.
- Rhinos have learned to fear humans. Exhibit defense behaviors if
the scent of humans is detected.
- Due to poor eyesight, they have learned to react to the alarm
reaction of other ungulates. If they detect a possible threat, but are
not able to see it from a distance, they often charge it just in case.
They have been observed charging tree trunks and termite mounds.
- Symbiotic relationships with other species:
- Cattle Egret- eats the insects stirred up by rhino as it walks;
often sits on its back, but rarely picks off ectoparasites.
- Fork-tailed drongo- sits on branches near rhino, swoops in and out
(much like flycatchers) eating insects that are attracted to it.
Does not follow rhino outside its home range.
- Red-billed Oxpecker- climbs on rhino (even into ears and nostrils)
and plucks off insects. Will follow rhino for long distances.
Also serves as alarm when danger approaches (very high pitched
- Elephants: although they share many of the same food plants,
rhinos and elephants usually do not interact with each other.
Exception- when food and water resources are scarce. Elephants can be
beneficial by digging wallows and pulling down branches with leaves
(elephants tend to eat larger branches, rather than the smaller
twigs). But they can be detrimental by disturbing the habitat
(destruction of trees and bushes).
DIET & FEEDING
(Kingdon, 1997)(Merz, 1991)
- The prehensile lip of the black rhino allows it to specialize on a
different diet than that of the white rhino.
- Browsers: eat leaves, twigs, and branches. Merz (1991) reported that
long grass may constitute up to 30%-40% of the diet, but grass
consumption is usually very low.
- White rhinos, in contrast, eat short grass and herbaceous plants, but
no leaves/twigs from trees or bushes.
- Up to 220 plant species recorded (99 woody, 102 herbs, and 25 grasses).
- Diet (quantity and species of plants) changes in relation to seasons
and rainfall (and therefore, availability).
- Horns used to dig up roots and break branches for better access to
- As with horses and zebras, digest food by bacterial fermentation in
hind gut .
- Dung is often inspected to detect diet. The difference between rhino
and elephant dung is that rhinos usually scrape the dung pile with its
back feet, flinging it away, and leaving two parallel grooves
emanating from the pile. Elephant dung is left in undisturbed piles.
Rhino dung contains small, short twigs, whereas elephant dung contains
longer, twisted pieces of woody fiber.
- Can go up to 5 days without drinking if food contains sufficient
moisture. If only dry forage is available, they will be found within a
day's travel to water.
- Handle drought conditions well compared to many other animal species in
the area. Not susceptible to poisonous tannins in plants that often
increase during a drought.
REPRODUCTION & DEVELOPMENT
(Bertschinger, 1995)(Estes, 1991)(Goddard, 1966 & 1967)
(Hillman-Smith & Groves, 1994)(Merz, 1991)
(Rookmaaker, 1998)(Schenkel & Schenkel-Hulliger, 1969)
- Characteristic courtship behaviors:
- Spraying- Males and females; see Olfaction/Scent
- Cocking the tail- Females, when sexually aroused; tail
lifts and is cocked at an angle
- Making flehman- Mostly males; seen in many other
ungulate groups; see Olfaction/Scent
- Dung scraping- Females; scrapes dung pile more
energetically (more often, with more force) than usual.
- When a female is in estrus, a male may follow her for a long
distance, trying to become accepted as a mating partner. May
follow calmly, approach with stiff, dragging legs, or
exhibit "Bluff and bluster"
display. Occasionally, male and female face each other
nudging heads and jousting with horns, neither of which is
done with great force.
- Polygamous: both males and females mate with more than one individual.
- Males do not defend harems of females, as seen in some ungulates.
However, males have been observed to defend a receptive female by
charging a potential competitor.
Gestation: 15-17 months in the wild; 15-18 months in
- Breeds year round; no discreet breeding season.
- Estrus lasts three days and occurs every 25-30 days
- Copulation lasts for half an hour or more.
- Partnering can last from one mating session, to days, weeks, or
- It can be difficult to tell when a female is in season. See Courtship
above for clues.
- It is also difficult to tell when a female is pregnant until a few days
before she gives birth.
- First parturition at 3.5 to 5.7 years old; varies group to group and
depends on density and resource availability.
- Interbirth Interval: 2.5 to 4 years
Infant (< 1 year old)
- Litter size: 1
- Birth weight: 27 - 45 kg
- Starts nibbling on solid food (grass; small, non-woody plants) in 7 to
- Independent of mother at 2.5 to 3 years old. When
new calf is born, mother rejects the older calf.
- May find a non-related adult to join after being rejected.
Longevity (Rookmaaker, 1998)
- Reports of sexual maturity vary widely
- Females: 3.5 to 4 years (Schenkel & Schenkel-Hulliger, 1969)
or maturity at 7 years and may conceive as young as 3.8 years
- Males: 6 years, fully grown at 8 to 10 years (Schenkel &
Schenkel-Hulliger, 1969) or maturity reached at 10 years (Estes,
- Fairly high mortality in zoos; approximately 60% have died within 10
years of being placed in captivity.
- Record longevity (as of 1994) for captive is 44 years old.
- Approximately 40 years in the wild.
- Drought: Survive better than many species, but still vulnerable
to its affects. New mothers and their calves are the most vulnerable
due to reduction in availability of nutritious food. Pregnant females
often abort their fetuses. Malnutrition kills an animal directly
or makes it more vulnerable to parasites and disease.
- Poachers: Because black rhinos tend to revisit the same resting
spots during the day, they are more vulnerable to poachers. See Threats to Survival for more on poaching.
- Predators: Humans are the main predators of rhinos. Lion and
hyena attacks on rhinos are rare, and usually only occurs with sick or
DISEASES AND PATHOLOGY
(Schenkel & Schenkel-Hulliger, 1969)
- Ticks- several species; mostly in folds of skin,
genital and anal regions, eyes, and ears
- Biting flies- several species; large numbers
congregate on the hide; suck blood mostly from saddle
region; seem to be discouraged by soil layer on skin from
- Microfilaria (small nematode worm) have been found in
ulcerating wounds; Stephanofilaria dinniki
- Intestinal helminths, in both small and large intestines; Anoplocephala
sp. and Kiluluma sp.
- Fly larvae, found in lining of the stomach; large size and
quantity; Gyrostigma sp.
- Roundworm; found in the conjunctiva (membrane of the eye);
(McKeever, 2000)(Ramirez, 1993)(Rookmaaker, 1998)
- Third century BC: first written records of rhinoceros being
exhibited, by the Romans. Sporadic exhibitions continued through the
3rd century AD.
- First through 14th century AD: often given as gifts in
- 6th (N. Africa) and 16th-17th centuries (Near East): sporadic
records of captivity.
- 1868: First black rhino in captivity in a European zoo.
- 1941: First born in captivity, Chicago Brookfield Zoo.
- 1952: San Diego Zoo obtains its first rhino (black).
- 1976: First black rhino born at the Wild Animal Park.
- 1992: First black rhino born at San Diego Zoo
- San Diego Zoo: south central black rhinos (Diceros
Wild Animal Park: northern white rhinos (Ceratotherium
simum cottoni), southern white rhinos (Ceratotherium simum
simum), eastern black rhinos (Diceros bicornis michaeli),
and Indian rhinos (Rhinoceros unicornis).
POPULATION AND CONSERVATION STATUS
(Ashley et al., 1990) (Emslie, 2002) (Emslie 2011)(Emslie & Brooks, 1999)
(Leader-Williams, 1992)(Schenkel & Schenkel-Hulliger, 1969)
- Wild/game reserve populations
- By Year
- 1800's: hundreds of thousands; fairly
continuous throughout much of sub-Saharan Africa
- 1970: 65,000; small, scattered, isolated
- 1990: 3,800; declined 94% in 20 years.
- 1992-1995: 2400-2500; stable
- 1999: 2700; slight increase
- 2001 - present: 3,100 (2001 = latest
estimate); slight increase continues.
- By Subspecies - 2001 estimates
- D. b. longipes (western): Most
endangered; only about 8 individuals (down from
110 in 1980) left in Cameroon; scattered. Now considered extinct (Emslie 2011)
- D. b. michaeli (eastern): Over 90%
decline in the last 50 years; 86.3% of total
population are in Kenya; population size = 498.
- D. b. bicornis (southwestern):
94.7% live in Namibia; have become locally extinct
in Rwanda since 1999; population = 943.
- D. b. minor (south central): Over 90%
decline in the last 50 years; 66.3% are in South
Africa, and 31.8% are in Zimbabwe; population =
- ISIS captive population
Threats to survival
- IUCN Status: CR (Critically Endangered)
- CITES Appendix: I or II
- Most rhinos now live in protected, managed game reserves.
- It is imperative to understand the seasonal shift in diet when setting
up protective reserves. Many rhinos have been poached after wandering
off a reserve looking for food during a drought.
- The threat of poaching is still so prevalent, that some
conservationists condone the practice of dehorning managed
populations, thus eliminating the temptation to poachers.
- Management through sustainable use is controversial (ecotourism, trophy
hunting, horn harvesting, and trade in rhino products).
- Unmanaged populations tend to be small and isolated, and
therefore, more vulnerable to disease, inbreeding, and local
- Vulnerability to poachers
- Poor eyesight; poachers can sneak up more easily as long as
they are down wind.
- Prior to human encroachment, rhinos did not suffer from
predation pressure and therefore, did not evolve behavior or
sensory capability to avoid predators. In Recent times they
have learned some avoidance tactics. See Interspecies Interactions for more
- Sedentary nature, and regular activity patterns (for example,
revisiting resting and watering spots), make it easier for
poachers to find them.
- Reasons for poaching
- Medicinal uses (most common): to help fevers, headaches,
toxins, typhoid, jaundice, rashes, vomiting or
excreting blood, to keep evil away, etc.
- Carved cups and dagger handles
- Aphrodisiac: contrary to popular thought, rarely used
this way; mostly by the Gujaratis in India.
- Asian ("fire") horns thought by some to be
more potent than African ("water") horns
resulting in more hunting pressure for Asian species.
- Blood (medicinal)
- Skin (medicinal)
- Poaching market, major consumers
- All rhino products: mostly China and Taiwan, but also Burma,
Thailand, and Nepal.
- Horns, medicinal uses: Japan and Korea
- Horns, dagger handles: Yemen (carved dagger handle is status
- Also a strong market in countries with immigrants from these
places (e.g., the Chinese living in the US)
- Problems enforcing conservation laws
- Civil war and political instability
- Poverty due to exponential population growth, hyperinflation,
- Well armed poaching gangs
- Competition for land (leading to habitat destruction) by
- Other comments on poaching
- It is likely that any improvement in health is due to the
placebo effect (because of strong traditional beliefs),
rather than to any real curative properties. Few scientific
studies have been done, and have conflicting results (see
- Earliest evidence of horn use for medical reasons: 2600 BC,
- It is still legal to sell rhino products in many countries,
and in others, enforcement is often lax.
Important Web Resources:
Return to the Fact Sheets page