Plains Zebra
Encyclopedia
The plains zebra also known as the common zebra or Burchell's zebra, is the most common and geographically widespread species of zebra
. It ranges from the south of Ethiopia
through East Africa to as far south as Angola
and eastern South Africa
. The plains zebra remains common in game reserve
s, but is threatened by human activities such as hunting for its meat and hide, as well as competition with livestock
and encroachment by farming on much of its habitat
.
belong to the subgenus
Hippotigris, but Grévy's zebra
is the sole species of subgenus Dolichohippus. The latter resembles an ass
, while the former two are more horse-like. All three belong to the genus Equus along with other living equids. Recent phylogenetic evidence suggests that Grevy's zebras (and perhaps also Mountain Zebras) are with asses and donkeys in a separate lineage from the Plains zebra. In areas where Plains zebras are sympatric with Grévy's zebras, it is not unusual to find them in the same herds and fertile hybrids occur. In captivity
, Plains zebras have been crossed with mountain zebras. The hybrid foals lacked a dewlap and resembled the plains zebra apart from their larger ears and their hindquarters pattern.
In 2004, C.P. Groves and C.H. Bell investigated the taxonomy of the zebra genus, Equus, subgenus Hippotigris. They published their research in Mammalian Biology. They revised the subspecies of the plains zebra Equus quagga. Six subspecies are now recognizable. The completely maneless Somali population may represent a seventh subspecies: Equus quagga isabella (Ziccardi, 1958). This subspecies may be valid, but at present there is no evidence that it is.
The quagga was originally classified as a separate species
, Equus quagga, in 1778. Over the next 50 years or so, many other zebras were described by naturalists and explorers. Because of the great variation in coat patterns (no two zebras are alike), taxonomists were left with a great number of described "species", and no easy way to tell which of these were true species, which were subspecies
, and which were simply natural variants. The quagga was the first extinct creature to have its DNA studied. Recent genetic research at the Smithsonian Institution
has demonstrated that the quagga was in fact not a separate species at all, but diverged from the plains zebra, between 120,000 and 290,000 years ago, and suggests that it should be named Equus burchelli quagga. However, according to the rules of biological nomenclature
, where there are two or more alternative names for a single species, the name first used takes priority. As the quagga was described about thirty years earlier than the Burchell's zebra, it appears that the correct terms are E. quagga quagga for the quagga and E. quagga burchelli for the plains zebra, unless "Equus burchelli" is officially declared to be a nomen conservandum.
The Burchell's zebra was thought to have been hunted to extinction
. However Groves and Bell concluded in their 2004 publication that "the extinct true Burchell's zebra" is a phantom. Careful study of the original zebra populations in Zululand
and Swaziland
, and of skins harvested on game farms in Zululand and Natal
, has revealed that a certain small proportion shows similarity to what now is regarded as typical "burchellii". The type localities of the subspecies Equus quagga burchellii and Equus quagga antiquorum (Damara zebra) are so close to each other that the two are in fact one, and that therefore the older of the two names should take precedence over the younger. They therefore say that the correct name for the southernmost subspecies must be burchellii not antiquorum. The subspecies Equus quagga burchellii still exists in KwaZulu-Natal
and in Etosha.
Like all zebras, they are boldly striped in black and white, and no two individuals look exactly alike. They also have black or dark muzzles. The natal coat of a foal is brown and white. All have vertical stripes on the forepart of the body, which tend towards the horizontal on the hindquarters. The northern populations have narrower and more defined striping; southern populations have varied but lesser amounts of striping on the underparts, the legs and the hindquarters. Southern populations also have brown "shadow" stripes between the black and white coloring. These are absent or poorly expressed in northern zebras.
Embroyoloical evidence has shown that the zebra's background color is dark and the white is an addition. The first subspecies to be described, the now-extinct quagga
, had plain brown hindquarters. (Technically, because the quagga was described first as E. quagga, the proper zoological name for the most common form of the plains zebra is E. quagga burchelli.) There have been various mutations of the zebra's pelage from mostly white to mostly black. Rare albino zebras have been recorded in the forests of Mount Kenya
.
the animal in tall grass or in the dappled shade beneath bushes and trees. However, animals that use camouflage, like the kudu
and bushbuck
, tend to be quiet and stealthy. They freeze when there is danger and flee only at the last moment. By contrast, the zebra is active and noisy, and makes no attempt to hide itself. Another suggestion is that the stripes affect a predator's judgement of the zebra's size, distance and what direction it is going in. However, zebra stripes do not appear to affect any of these. A related hypothesis is that the stripes make it difficult for a predator to single out and focus on an individual during a chase. Perhaps the best explanation for the stripes is that they serve a social function. Individual zebras can apparently recognize each other by their stripe patterns. The stripes may also serve as visual cues for grooming. In addition, they may also serve to help zebra groups stay together when they are fleeing.
from southern Sudan and southern Ethiopia extending south along eastern Africa, as far as Zambia, Mozambique, and Malawi, before spreading into most southern African countries. They are regionally extinct in Burundi and Lesotho, and they may have lived in Algeria in the Neolithic Era.
Plains zebras generally live in treeless grasslands and savanna woodlands but can be found in a variety of habitats, both tropical and temperate. However they are generally absent from deserts, dense rainforests and permanent wetlands. Zebras also live in elevations from sea level
to on Mount Kenya. They rely on rainfall for food and water, and go on great migrations to follow the rains. The zebras will migrate up to 700 miles (1,126.5 km) for food. Other grazers also migrate. Plains zebras are highly water-dependent and are usually found within 25–30 kilometers of a water source.
, 5% herb
s, and 2% shrub
s. Unlike many of the large ungulate
s of Africa, the plains zebra does not require (but still prefers) short grass to graze. It eats a wide range of different grasses, preferring young, fresh growth where available, and also browses on leaves and shoots from time to time. In consequence, it ranges more widely than many other species, even into woodland
s, and it is often the first grazing species to appear in a well-vegetated area. Zebras have a simple stomach and use hindgut fermentation
(caeco-colic) which allows them to digest and assimilate larger amounts of forage during a 24-hour period. Thus, zebras are less selective in foraging, but they do spend much time eating. The zebra is a pioneer grazer and prepares the way for more specialized grazers like blue wildebeest
s and Thomson's gazelle
s who depend on shorter and more nutritional grasses.
The plains zebra's major predators are lion
s and spotted hyena
s. Nile crocodile
s are also great threats during river crossings. Wild dog
s, cheetah
s, and leopard
s also prey on zebras, although the threats they pose are generally minor. Hyenas, dogs, cheetahs, and leopards mostly attack zebra foals.
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The plains zebra is highly social and usually forms small family groups called harems
, which consist of a single stallion, several mares, and their recent offspring. The adult membership of a harem is highly stable, typically remaining together for months to years. Groups of all male "bachelors" also exist. These are stable groups of 2-15 males with an age-based hierarchy lead by a young male. These males stay in their groups until they are ready to start a harem. The bachelors spend much time "rehearsing" their adult roles with play fights and greeting/challenge rituals. Multiple harems and bachelor groups come together to form herds. Plains zebras are unusual among harem-holding species in forming these groups. In addition, pairs of harems may create temporarily stable subgroups within a herd. Zebra interactions with those outside their core group may reflect a second tier of social relationships that critically shape the society of the plains zebra. Among harem-holding species, this has only been observed in primates like the gelada
and the hamadryas baboon
.
Stallions form harems by abducting young mares from their family harems. When a mare reaches sexual maturity, she will exhibit the estrous posture, which attracts nearby stallions, both bachelors and harem leaders. Her harem stallion (usually her father) will chase off or fight stallions attempting to abduct her. Even after a young mare is isolated from her natal harem, the fight over her continues until her estrous cycle is over, and it starts again with the next estrous cycle. It is rare that the mare's original abductor keeps her for long. When the mare finally ovulates
, the male that impregnates her keeps her for good. Thus, the mare becomes a permanent member of a new harem.
Mares exist in a hierarchy, with the alpha female being the first to mate with the stallion and being the one to lead the group. When new mares are added to the group, they are met with hostility by the other mares. Thus, the stallion must shield the new mares until the aggression subsides. The most recently added females rank lowest. Females that become unfit or weak may drop in their rank, though. The female memberships of a harem stay intact even if a new stallion takes over. Zebras strengthen their social bonds with grooming. Members of a harem nip and scrape along the neck, shoulders, and back with their teeth and lips. Mothers and foals groom the most often, followed by siblings. Grooming shows social status and eases aggressive behavior.
A stallion will defend his group from other males. When challenged, the stallion would issue a warning to the invader by rubbing nose or shoulder with him. If the warning is not heeded, a fight breaks out. Zebra fights often become very violent, with the animals biting at each other's necks, heads or legs, wrestling to the ground, and occasional kicking. Sometimes a stallion will lie still on the ground as if surrendering, but once the other male lets up, will strike and continue the fight. Most fighting occurs over young mares in estrus, and as long as a harem stallion is healthy, he will usually not be challenged. Only unhealthy stallions have their harems taken over, and even then the new stallion gradually takes over pushing the old one out without a fight.
and feticide
, although such incidences have only been observed in captive individuals. Like horses, zebras are able to stand, walk, and suckle shortly after they are born. At the moment of birth, a mother zebra keeps any other zebra away from her foal, including the stallion, the other mares, and even the previous offspring. Later, though, they all bond. Plains zebra foals are protected by their mother as well as the head stallion and the other mares in their group. Even with parental protection, up to 50% of zebra foals are taken by predation, disease, and starvation each year.
Young male zebras eventually leave their family groups. This is not because of sexual maturity or being kicked out by their fathers, but because their relationship with their mothers have faded after the birth of a sibling. The young stallion then seeks out other young stallions for company. Young females may stay in the harem until they are abducted by another stallion.
in Tanzania, Tsavo
and Masai Mara
in Kenya, Hwange National Park
in Zimbabwe, Etosha National Park
in Namibia, and Kruger National Park
in South Africa. There are some stable populations in unprotected areas.
Some local populations, though, have faced great declines and even extinctions. One subspecies, the quagga, is now extinct. In Tanzania, the zebra population has decreased by 20% from the late 1990s to the mid 2000s. Zebras are threatened by hunting for their hide and meat, and habitat change from farming. They also compete with livestock for food, and are sometimes culled. Poaching is largely a threat to northern populations, while southern populations are threatened mostly by habitat loss. Recent civil wars in Rwanda
, Somalia
, Sudan
, Ethiopia
, and Uganda
have caused dramatic declines in all wildlife populations, including those of plains zebra. It is now extinct in Burundi
. Civil war in Angola
during much of the past 25 years has devastated its wildlife populations, including its once-abundant plains zebra, and destroyed the national parks administration and infrastructure.
Nevertheless, plains zebras are protected in most of their range. They are an important economic source in tourism.
tribe of South Africa features a zebra on its totem
. Zebras also appear on the coat of arms of Botswana
.
Zebra
Zebras are several species of African equids united by their distinctive black and white stripes. Their stripes come in different patterns unique to each individual. They are generally social animals that live in small harems to large herds...
. It ranges from the south of Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
through East Africa to as far south as Angola
Angola
Angola, officially the Republic of Angola , is a country in south-central Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city...
and eastern South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
. The plains zebra remains common in game reserve
Game reserve
A game reserve is an area of land set aside for maintenance of wildlife for tourism or hunting purposes. Many game reserves are located in Africa. Most are open to the public, and tourists commonly take sightseeing safaris or hunt wild game....
s, but is threatened by human activities such as hunting for its meat and hide, as well as competition with livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
and encroachment by farming on much of its habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
.
Taxonomy
The Plains zebra and perhaps the mountain zebraMountain Zebra
The Mountain Zebra, Equus zebra, is a threatened species of equid native to south-western Angola, Namibia and South Africa. It has two subspecies, the Cape Mountain Zebra and Hartmann's Mountain Zebra , though it has been suggested these should be considered separate species.-Taxonomy:In 2004,...
belong to the subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
Hippotigris, but Grévy's zebra
Grevy's Zebra
The Grévy's zebra , also known as the Imperial zebra, is the largest extant wild equid and one of three species of zebra, the other two being the plains zebra and the mountain zebra. Named after Jules Grévy, it is the sole extant member of the subgenus Dolichohippus. The Grévy's zebra is found in...
is the sole species of subgenus Dolichohippus. The latter resembles an ass
Asinus
The subgenus Asinus encompasses four species and several subspecies of Equidae characterized by long ears, a lean, straight-backed build, a scant tail, and a reputation for considerable toughness and endurance....
, while the former two are more horse-like. All three belong to the genus Equus along with other living equids. Recent phylogenetic evidence suggests that Grevy's zebras (and perhaps also Mountain Zebras) are with asses and donkeys in a separate lineage from the Plains zebra. In areas where Plains zebras are sympatric with Grévy's zebras, it is not unusual to find them in the same herds and fertile hybrids occur. In captivity
Captivity (animal)
Animals that live under human care are in captivity. Captivity can be used as a generalizing term to describe the keeping of either domesticated animals or wild animals. This may include for example farms, private homes and zoos...
, Plains zebras have been crossed with mountain zebras. The hybrid foals lacked a dewlap and resembled the plains zebra apart from their larger ears and their hindquarters pattern.
Subspecies
- QuaggaQuaggaThe quagga is an extinct subspecies of the plains zebra, which was once found in great numbers in South Africa's Cape Province and the southern part of the Orange Free State. It was distinguished from other zebras by having the usual vivid marks on the front part of the body only...
, †ExtinctionIn biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
Equus quagga quagga – Boddaert, 1785 - Burchell's zebraBurchell's ZebraBurchell's Zebra is a southern subspecies of the Plains Zebra.-Range:Formerly Burchell's zebra ranged north of the Vaal/Orange river system, extending northwest via southern Botswana to Etosha and the Kaokoveld, southeast to Swaziland and Kwazulu-Natal...
, Equus quagga burchellii – Gray, 1824 - Grant's zebraGrant's ZebraThe Grant's Zebra is the smallest of six subspecies of the Plains Zebra.-Distribution:The distribution of this subspecies is in Zambia west of the Luangwa river and west to Kariba, Shaba Province of the Democratic Republic of the Congo, north to the Kibanzao Plateau. In Tanzania north from...
, Equus quagga boehmi – Matschie, 1892 - Selous' ZebraSelous' ZebraThe Selous' Zebra, is one of the six subspecies of the Plains Zebra, spread over southeastern Africa. It is spread mostly in Mozambique, but nowadays it is endangered...
, Equus quagga borensis – Lönnberg, 1921 - Chapman's zebraChapman's ZebraChapman's Zebra is a subspecies of Plains Zebra.They, like their relatives, are native to the savannah of north-east South Africa, north to Zimbabwe, west into Botswana, the Caprivi Strip in Namibia, and southern Angola. The Chapman's zebra eats mainly grass and occasionally shrubs...
, Equus quagga chapmani – Layard, 1865 - Crawshay's ZebraCrawshay's ZebraThe Crawshay's zebra is a subspecies of the plains zebra. It is native to eastern Zambia, Malawi, and northern Mozambique. Crawshay's zebras can be distinguished from other subspecies of plains zebras in that its lower incisors lack an infundibulum....
, Equus quagga crawshayi – De Winton, 1896
The quagga was originally classified as a separate species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
, Equus quagga, in 1778. Over the next 50 years or so, many other zebras were described by naturalists and explorers. Because of the great variation in coat patterns (no two zebras are alike), taxonomists were left with a great number of described "species", and no easy way to tell which of these were true species, which were subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
, and which were simply natural variants. The quagga was the first extinct creature to have its DNA studied. Recent genetic research at the Smithsonian Institution
Smithsonian Institution
The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...
has demonstrated that the quagga was in fact not a separate species at all, but diverged from the plains zebra, between 120,000 and 290,000 years ago, and suggests that it should be named Equus burchelli quagga. However, according to the rules of biological nomenclature
Binomial nomenclature
Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...
, where there are two or more alternative names for a single species, the name first used takes priority. As the quagga was described about thirty years earlier than the Burchell's zebra, it appears that the correct terms are E. quagga quagga for the quagga and E. quagga burchelli for the plains zebra, unless "Equus burchelli" is officially declared to be a nomen conservandum.
The Burchell's zebra was thought to have been hunted to extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
. However Groves and Bell concluded in their 2004 publication that "the extinct true Burchell's zebra" is a phantom. Careful study of the original zebra populations in Zululand
Zulu Kingdom
The Zulu Kingdom, sometimes referred to as the Zulu Empire or, rather imprecisely, Zululand, was a monarchy in Southern Africa that extended along the coast of the Indian Ocean from the Tugela River in the south to Pongola River in the north....
and Swaziland
Swaziland
Swaziland, officially the Kingdom of Swaziland , and sometimes called Ngwane or Swatini, is a landlocked country in Southern Africa, bordered to the north, south and west by South Africa, and to the east by Mozambique...
, and of skins harvested on game farms in Zululand and Natal
KwaZulu-Natal
KwaZulu-Natal is a province of South Africa. Prior to 1994, the territory now known as KwaZulu-Natal was made up of the province of Natal and the homeland of KwaZulu....
, has revealed that a certain small proportion shows similarity to what now is regarded as typical "burchellii". The type localities of the subspecies Equus quagga burchellii and Equus quagga antiquorum (Damara zebra) are so close to each other that the two are in fact one, and that therefore the older of the two names should take precedence over the younger. They therefore say that the correct name for the southernmost subspecies must be burchellii not antiquorum. The subspecies Equus quagga burchellii still exists in KwaZulu-Natal
KwaZulu-Natal
KwaZulu-Natal is a province of South Africa. Prior to 1994, the territory now known as KwaZulu-Natal was made up of the province of Natal and the homeland of KwaZulu....
and in Etosha.
Physical description
The plains zebra is mid-sized, smaller on average than the other two zebra species, and thick bodied with relatively short legs. There is some variation in size, based on the animals' condition and subspecies. Adults of both sexes can stand from 1.1 to 1.47 m (3.6 to 4.8 ft) high at the shoulder, are 2 to 2.5 m (6.6 to 8.2 ft) long, not counting a 50 cm (19.7 in) tail, and weigh 175 to 387 kg (385.8 to 853.2 lb). Males may weigh 10% more than females.Like all zebras, they are boldly striped in black and white, and no two individuals look exactly alike. They also have black or dark muzzles. The natal coat of a foal is brown and white. All have vertical stripes on the forepart of the body, which tend towards the horizontal on the hindquarters. The northern populations have narrower and more defined striping; southern populations have varied but lesser amounts of striping on the underparts, the legs and the hindquarters. Southern populations also have brown "shadow" stripes between the black and white coloring. These are absent or poorly expressed in northern zebras.
Embroyoloical evidence has shown that the zebra's background color is dark and the white is an addition. The first subspecies to be described, the now-extinct quagga
Quagga
The quagga is an extinct subspecies of the plains zebra, which was once found in great numbers in South Africa's Cape Province and the southern part of the Orange Free State. It was distinguished from other zebras by having the usual vivid marks on the front part of the body only...
, had plain brown hindquarters. (Technically, because the quagga was described first as E. quagga, the proper zoological name for the most common form of the plains zebra is E. quagga burchelli.) There have been various mutations of the zebra's pelage from mostly white to mostly black. Rare albino zebras have been recorded in the forests of Mount Kenya
Mount Kenya
Mount Kenya is the highest mountain in Kenya and the second-highest in Africa, after Kilimanjaro. The highest peaks of the mountain are Batian , Nelion and Point Lenana . Mount Kenya is located in central Kenya, just south of the equator, around north-northeast of the capital Nairobi...
.
Function of the stripes
The striping pattern of the zebra is unique among sympatric ungulates. One suggested function for the stripes is to camouflageCamouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
the animal in tall grass or in the dappled shade beneath bushes and trees. However, animals that use camouflage, like the kudu
Kudu
The kudus are two species of antelope of the genus Tragelaphus:*Lesser Kudu, Tragelaphus imberbis*Greater Kudu, Tragelaphus strepsiceros- Etymology :...
and bushbuck
Bushbuck
The bushbuck is the most widespread antelope in Sub-Saharan Africa, and is found in rain forests, montane forests, forest-savanna mosaics and bush savannaforest and woodland. Recently, genetic studies have shown that the bushbuck, is in fact a complex of two geographically and phenotypically...
, tend to be quiet and stealthy. They freeze when there is danger and flee only at the last moment. By contrast, the zebra is active and noisy, and makes no attempt to hide itself. Another suggestion is that the stripes affect a predator's judgement of the zebra's size, distance and what direction it is going in. However, zebra stripes do not appear to affect any of these. A related hypothesis is that the stripes make it difficult for a predator to single out and focus on an individual during a chase. Perhaps the best explanation for the stripes is that they serve a social function. Individual zebras can apparently recognize each other by their stripe patterns. The stripes may also serve as visual cues for grooming. In addition, they may also serve to help zebra groups stay together when they are fleeing.
Range and habitat
The Plains zebra's range stops short of the SaharaSahara
The Sahara is the world's second largest desert, after Antarctica. At over , it covers most of Northern Africa, making it almost as large as Europe or the United States. The Sahara stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean...
from southern Sudan and southern Ethiopia extending south along eastern Africa, as far as Zambia, Mozambique, and Malawi, before spreading into most southern African countries. They are regionally extinct in Burundi and Lesotho, and they may have lived in Algeria in the Neolithic Era.
Plains zebras generally live in treeless grasslands and savanna woodlands but can be found in a variety of habitats, both tropical and temperate. However they are generally absent from deserts, dense rainforests and permanent wetlands. Zebras also live in elevations from sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
to on Mount Kenya. They rely on rainfall for food and water, and go on great migrations to follow the rains. The zebras will migrate up to 700 miles (1,126.5 km) for food. Other grazers also migrate. Plains zebras are highly water-dependent and are usually found within 25–30 kilometers of a water source.
Diet and predation
In one study, the zebra's diet was estimated to be 92% grassGrass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
, 5% herb
Herb
Except in botanical usage, an herb is "any plant with leaves, seeds, or flowers used for flavoring, food, medicine, or perfume" or "a part of such a plant as used in cooking"...
s, and 2% shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s. Unlike many of the large ungulate
Ungulate
Ungulates are several groups of mammals, most of which use the tips of their toes, usually hoofed, to sustain their whole body weight while moving. They make up several orders of mammals, of which six to eight survive...
s of Africa, the plains zebra does not require (but still prefers) short grass to graze. It eats a wide range of different grasses, preferring young, fresh growth where available, and also browses on leaves and shoots from time to time. In consequence, it ranges more widely than many other species, even into woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
s, and it is often the first grazing species to appear in a well-vegetated area. Zebras have a simple stomach and use hindgut fermentation
Hindgut fermentation
Hindgut fermentation is a digestive process seen in monogastric herbivores, animals with a simple, single-chambered stomach. Cellulose is digested with the aid of symbiotic bacteria. The microbial fermentation occurs in the digestive organs that follow the small intestine, namely the large...
(caeco-colic) which allows them to digest and assimilate larger amounts of forage during a 24-hour period. Thus, zebras are less selective in foraging, but they do spend much time eating. The zebra is a pioneer grazer and prepares the way for more specialized grazers like blue wildebeest
Blue Wildebeest
The Blue Wildebeest , also called the Common Wildebeest, is a large antelope and one of two species of wildebeest. It grows to 115–145 cm shoulder height and attains a body mass of 168–274 kg. They range the open plains, bushveld and dry woodlands of Southern and East Africa, living for...
s and Thomson's gazelle
Thomson's Gazelle
The Thomson's gazelle is one of the best-known gazelles. It is named after explorer Joseph Thomson and, as a result, is sometimes referred to as a "tommie"...
s who depend on shorter and more nutritional grasses.
The plains zebra's major predators are lion
Lion
The lion is one of the four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg in weight, it is the second-largest living cat after the tiger...
s and spotted hyena
Spotted Hyena
The spotted hyena also known as laughing hyena, is a carnivorous mammal of the family Hyaenidae, of which it is the largest extant member. Though the species' prehistoric range included Eurasia extending from Atlantic Europe to China, it now only occurs in all of Africa south of the Sahara save...
s. Nile crocodile
Nile crocodile
The Nile crocodile or Common crocodile is an African crocodile which is common in Somalia, Ethiopia, Uganda, Kenya, Egypt, Tanzania, Zambia, Zimbabwe, Gabon, South Africa, Malawi, Sudan, Botswana, and Cameroon...
s are also great threats during river crossings. Wild dog
African Wild Dog
Lycaon pictus is a large canid found only in Africa, especially in savannas and lightly wooded areas. It is variously called the African wild dog, African hunting dog, Cape hunting dog, painted dog, painted wolf, painted hunting dog, spotted dog, or ornate wolf...
s, cheetah
Cheetah
The cheetah is a large-sized feline inhabiting most of Africa and parts of the Middle East. The cheetah is the only extant member of the genus Acinonyx, most notable for modifications in the species' paws...
s, and leopard
Leopard
The leopard , Panthera pardus, is a member of the Felidae family and the smallest of the four "big cats" in the genus Panthera, the other three being the tiger, lion, and jaguar. The leopard was once distributed across eastern and southern Asia and Africa, from Siberia to South Africa, but its...
s also prey on zebras, although the threats they pose are generally minor. Hyenas, dogs, cheetahs, and leopards mostly attack zebra foals.
Interactions with other grazers
Plains zebra herds will mix and migrate together along with other species such as wildebeests. Wildebeests and zebras generally coexist peacefully and will alert each other to predators. However, aggressive interactions occasionally occur.Social structure
Harem (zoology)
The term harem is used in zoology to describe the social organization of certain herbivore species, such as those in the Hominidae and Equidae families, into groups of females and young surrounding a single dominant male...
, which consist of a single stallion, several mares, and their recent offspring. The adult membership of a harem is highly stable, typically remaining together for months to years. Groups of all male "bachelors" also exist. These are stable groups of 2-15 males with an age-based hierarchy lead by a young male. These males stay in their groups until they are ready to start a harem. The bachelors spend much time "rehearsing" their adult roles with play fights and greeting/challenge rituals. Multiple harems and bachelor groups come together to form herds. Plains zebras are unusual among harem-holding species in forming these groups. In addition, pairs of harems may create temporarily stable subgroups within a herd. Zebra interactions with those outside their core group may reflect a second tier of social relationships that critically shape the society of the plains zebra. Among harem-holding species, this has only been observed in primates like the gelada
Gelada
The gelada , sometimes called the gelada baboon, is a species of Old World monkey found only in the Ethiopian Highlands, with large populations in the Semien Mountains...
and the hamadryas baboon
Hamadryas Baboon
The Hamadryas baboon is a species of baboon from the Old World monkey family. It is the northernmost of all the baboons; being native to the Horn of Africa and the southwestern tip of the Arabian Peninsula. These regions provide habitats with the advantage for this species of fewer natural...
.
Stallions form harems by abducting young mares from their family harems. When a mare reaches sexual maturity, she will exhibit the estrous posture, which attracts nearby stallions, both bachelors and harem leaders. Her harem stallion (usually her father) will chase off or fight stallions attempting to abduct her. Even after a young mare is isolated from her natal harem, the fight over her continues until her estrous cycle is over, and it starts again with the next estrous cycle. It is rare that the mare's original abductor keeps her for long. When the mare finally ovulates
Ovulation
Ovulation is the process in a female's menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum . Ovulation also occurs in the estrous cycle of other female mammals, which differs in many fundamental ways from the menstrual cycle...
, the male that impregnates her keeps her for good. Thus, the mare becomes a permanent member of a new harem.
A stallion will defend his group from other males. When challenged, the stallion would issue a warning to the invader by rubbing nose or shoulder with him. If the warning is not heeded, a fight breaks out. Zebra fights often become very violent, with the animals biting at each other's necks, heads or legs, wrestling to the ground, and occasional kicking. Sometimes a stallion will lie still on the ground as if surrendering, but once the other male lets up, will strike and continue the fight. Most fighting occurs over young mares in estrus, and as long as a harem stallion is healthy, he will usually not be challenged. Only unhealthy stallions have their harems taken over, and even then the new stallion gradually takes over pushing the old one out without a fight.
Communication
Zebras communicate with each other with high pitched barks and whinnying. A zebra's ears signify its mood. When a zebra is in a calm, tense or friendly mood, its ears stand erect. When it is frightened, its ears are pushed forward. When angry, the ears are pulled backward. When surveying an area for predators, zebras will stand in an alert posture, with ears erect, head held high, and staring. When tense, they will also snort. When a predator is spotted or sensed, a zebra will bark loudly.Reproduction
The stallion mates with all his mares. Mares may give birth to one foal every twelve months. The birthing peak is during the rainy season. She nurses the foal for up to a year. The stallion is generally intolerant of foals that are not his. It is possible that zebras practice infanticideInfanticide (zoology)
In animals, infanticide involves the killing of young offspring by a mature animal of its own species, and is studied in zoology, specifically in the field of ethology. Ovicide is the analogous destruction of eggs. Although human infanticide has been widely studied, the practice has been observed...
and feticide
Feticide
Feticide is an act that causes the death of a fetus. In a legal context, "fetal homicide" or "child destruction" refers to the deliberate or incidental killing of a fetus due to a criminal human act, such as a blow to the abdomen of a pregnant woman...
, although such incidences have only been observed in captive individuals. Like horses, zebras are able to stand, walk, and suckle shortly after they are born. At the moment of birth, a mother zebra keeps any other zebra away from her foal, including the stallion, the other mares, and even the previous offspring. Later, though, they all bond. Plains zebra foals are protected by their mother as well as the head stallion and the other mares in their group. Even with parental protection, up to 50% of zebra foals are taken by predation, disease, and starvation each year.
Young male zebras eventually leave their family groups. This is not because of sexual maturity or being kicked out by their fathers, but because their relationship with their mothers have faded after the birth of a sibling. The young stallion then seeks out other young stallions for company. Young females may stay in the harem until they are abducted by another stallion.
Anti-predator behavior
For protection from land predators, the plains zebra retreats into open areas with good visibility at night. When the groups forage or sleep, one zebra will keep watch, and if a predator is spotted, it will bark or snort loudly. When being hunted by hyenas or wild dogs, a zebra harem stays close together and cooperates to protect threatened members, particularly the young. The harem stallion will go on the offensive and attack the dogs or hyenas. Though hyenas may harass the stallion, they usually only concentrate on the herd, and attempt to dodge the stallion's assaults. Unlike stallions, mares typically only react aggressively to hyenas or dogs when their foals are threatened. Unlike wildebeest, zebras rarely take to water when escaping hyenas. With lions, a zebra's best defense is to outpace them, as lions do not have as much endurance as hyenas or wild dogs. Cheetahs and leopards are mostly threats to foals as an adult zebra is fully capable of driving them away.Conservation
Overall, the plains zebra population remains stable, and the species faces no major threat that would cause range-wide decline. The zebra can be found in numerous protected areas across its range, including the Serengeti National ParkSerengeti National Park
The Serengeti National Park is a large national park in Serengeti area, Tanzania. It is most famous for its annual migration of over one and a half million white bearded wildebeest and 250,000 zebra...
in Tanzania, Tsavo
Tsavo
Tsavo is a region of Kenya located at the crossing of the Uganda Railway over the Tsavo River, close to where it meets the Athi River. It is a KiKamba word meaning "a place of slaughter", a reference to the murderous attacks of Maasai morani on Kamba people there...
and Masai Mara
Masai Mara
The Maasai Mara National Reserve is a large game reserve in south-western Kenya, which is effectively the northern continuation of the Serengeti National Park in Tanzania...
in Kenya, Hwange National Park
Hwange National Park
Hwange National Park is the largest game reserve in Zimbabwe. The park lies in the west, on the main road between Bulawayo and the widely noted Victoria Falls.It was founded around 1928 by a 22-year-old game ranger, Ted Davidson...
in Zimbabwe, Etosha National Park
Etosha National Park
Etosha National Park is a national park in the Kunene Region of northwestern Namibia. The park shares boundaries with the regions of Oshana, Oshikoto and Otjozondjupa....
in Namibia, and Kruger National Park
Kruger National Park
Kruger National Park is one of the largest game reserves in Africa. It covers and extends from north to south and from east to west.To the west and south of the Kruger National Park are the two South African provinces of Limpopo and Mpumalanga. In the north is Zimbabwe, and to the east is...
in South Africa. There are some stable populations in unprotected areas.
Rwanda
Rwanda or , officially the Republic of Rwanda , is a country in central and eastern Africa with a population of approximately 11.4 million . Rwanda is located a few degrees south of the Equator, and is bordered by Uganda, Tanzania, Burundi and the Democratic Republic of the Congo...
, Somalia
Somalia
Somalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...
, Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...
, Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
, and Uganda
Uganda
Uganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...
have caused dramatic declines in all wildlife populations, including those of plains zebra. It is now extinct in Burundi
Burundi
Burundi , officially the Republic of Burundi , is a landlocked country in the Great Lakes region of Eastern Africa bordered by Rwanda to the north, Tanzania to the east and south, and the Democratic Republic of the Congo to the west. Its capital is Bujumbura...
. Civil war in Angola
Angola
Angola, officially the Republic of Angola , is a country in south-central Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city...
during much of the past 25 years has devastated its wildlife populations, including its once-abundant plains zebra, and destroyed the national parks administration and infrastructure.
Nevertheless, plains zebras are protected in most of their range. They are an important economic source in tourism.
In culture
The zebra is revered in some African cultures as a symbol of beauty. In the dances of the Karamojong tribe of Uganda, women would paint themselves in zebra stripes and act like them. The DubeJohn Langalibalele Dube
John Langalibalele Dube was a South African essayist, philosopher, educator, politician, publisher, editor, novelist and poet. He was the founding president of the South African Native National Congress which became the African National Congress in 1923...
tribe of South Africa features a zebra on its totem
Totem
A totem is a stipulated ancestor of a group of people, such as a family, clan, group, lineage, or tribe.Totems support larger groups than the individual person. In kinship and descent, if the apical ancestor of a clan is nonhuman, it is called a totem...
. Zebras also appear on the coat of arms of Botswana
Coat of arms of Botswana
The coat of arms of Botswana was adopted on January 25, 1966. The centre shield is supported by two zebras. The shape of the shield is that of traditional shields found in East Africa...
.
General references
- Alden, P. C., Estes, R.D., Schlitter, D., McBride, B. (1995). National Audubon Society Field Guide to African Wildlife. New York, Chanticleer Press, Inc. pg. 151
- Apps, P., du Toit, R. (2006). Creatures of Habit: Understanding African Animal Behaviour. Struik. pgs. 74-75.
- Estes, R. (1991). The Behavior Guide to African Mammals, Including Hoofed Mammals, Carnivores, Primates. Los Angeles, University of California Press. pgs. 242–246
- Groves, C.P. and Bell, H.B. 2004. New investigations on the taxonomy of the zebras genus Equus, subgenus Hippotigris. Mammalian Biology. 69: 182–196. (Extinct subspecies of the Plains Zebra.)
- Higuchi et al. (1987). Mitochondrial DNA of the Extinct Quagga: Relatedness and Extent of Postmortem Change. Journal of Molecular Evolution 25:283–287.
- Kingdon, J. (1988). East African Mammals: An Atlas of Evolution in Africa, Volume 3, Part B: Large Mammals. Chicago, University of Chicago Press. pgs. 165–179
- Klingel, H., (1969). Reproduction in the plains zebra Equus burchelli boehmi: behaviour and ecological factors. J. Reprod. Fertil., Suppl. 6: 339–345.
- Moelman, P.D. 2002. Equids. Zebras, Assess and Horses. Status Survey and Conservation Action Plan. IUCN/SSC Equid Specialist Group. IUCN, Gland, Switzerland. Chapter 4. Status and Action Plan for the Plains Zebra (Equus burchelli). Mace A. Hack, Rod East and Dan J Rubenstein. pgs. 43–57.
- Moehlman, P. D. (2003). Grizmek's Animal Life Encyclopedia. Mammals IV. Detroit, The Gale Group, Inc. 15.
- Moss, C., Ed. (1982). Portraits in the Wild, Animal Behavior in East Africa. Chicago, University of Chicago Press.
- Prothero, D. R.; Schoch, R. M. (2003). Horns, Tusks, and Flippers: The Evolution of Hoofed Mammals. Johns Hopkins University Press.
- Rubenstein, D. I. & M. Hack (2004) Natural and sexual selection and the evolution of multi-level societies: insights from zebras with comparisons to primates. pp. 266–279. In: Sexual Selection in Primates: New and Comparative Perspectives. P. Kappeler and C. P. van Schaik (eds.). Cambridge University Press.