Zebra (Harvey)
   HOME

TheInfoList



OR:

Zebras (, ) (subgenus ''Hippotigris'') are African equines with distinctive black-and-white striped
coat A coat typically is an outer garment for the upper body as worn by either gender for warmth or fashion. Coats typically have long sleeves and are open down the front and closing by means of buttons, zippers, hook-and-loop fasteners, toggles, a ...
s. There are three living species: the
Grévy's zebra Grévy's zebra (''Equus grevyi''), also known as the imperial zebra, is the largest living wild equid and the most threatened of the three species of zebra, the other two being the plains zebra and the mountain zebra. Named after Jules Grévy, i ...
(''Equus grevyi''), plains zebra (''E. quagga''), and the mountain zebra (''E. zebra''). Zebras share the genus ''Equus'' with
horses The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million yea ...
and asses, the three groups being the only living members of the family Equidae. Zebra stripes come in different patterns, unique to each individual. Several theories have been proposed for the function of these stripes, with most evidence supporting them as a deterrent for biting flies. Zebras inhabit eastern and southern Africa and can be found in a variety of habitats such as savannahs,
grasslands A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natural ...
, woodlands,
shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity. It m ...
s, and mountainous areas. Zebras are primarily grazers and can subsist on lower-quality vegetation. They are preyed on mainly by lions, and typically flee when threatened but also bite and kick. Zebra species differ in social behaviour, with plains and mountain zebra living in stable harems consisting of an adult male or
stallion A stallion is a male horse that has not been gelded (castrated). Stallions follow the conformation and phenotype of their breed, but within that standard, the presence of hormones such as testosterone may give stallions a thicker, "cresty" nec ...
, several adult females or
mares A mare is an adult female horse or other equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more than four y ...
, and their young or
foals A foal is an equine up to one year old; this term is used mainly for horses, but can be used for donkeys. More specific terms are colt for a male foal and filly for a female foal, and are used until the horse is three or four. When the foal is ...
; while Grévy's zebra live alone or in loosely associated herds. In harem-holding species, adult females mate only with their harem stallion, while male Grévy's zebras establish territories which attract females and the species is promiscuous. Zebras communicate with various vocalisations, body postures and facial expressions.
Social grooming Social grooming is a behavior in which social animals, including humans, clean or maintain one another's body or appearance. A related term, allogrooming, indicates social grooming between members of the same species. Grooming is a major soci ...
strengthens social bonds in plains and mountain zebras. Zebras' dazzling stripes make them among the most recognisable mammals. They have been featured in art and stories in Africa and beyond. Historically, they have been highly sought after by exotic animal collectors, but unlike
horses The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million yea ...
and donkeys, zebras have never been truly domesticated. The International Union for Conservation of Nature (IUCN) lists the Grévy's zebra as endangered, the mountain zebra as
vulnerable Vulnerable may refer to: General * Vulnerability * Vulnerability (computing) * Vulnerable adult * Vulnerable species Music Albums * ''Vulnerable'' (Marvin Gaye album), 1997 * ''Vulnerable'' (Tricky album), 2003 * ''Vulnerable'' (The Used album) ...
and the plains zebra as near-threatened. The quagga (''E. quagga quagga''), a type of plains zebra, was driven to extinction in the 19th century. Nevertheless, zebras can be found in numerous protected areas.


Etymology

The English name "zebra" derives from Italian, Spanish or Portuguese. Its origins may lie in the Latin ''equiferus'', meaning "wild horse". ''Equiferus'' appears to have entered into Portuguese as ''ezebro'' or ''zebro'', which was originally used for a legendary equine in the wilds of the Iberian Peninsula during the Middle Ages. In 1591, Italian explorer Filippo Pigafetta recorded "zebra" being used to refer to the African animals by Portuguese visitors to the continent. In ancient times, the African zebra was called ''hippotigris'' ("horse tiger") by the Greeks and Romans. The word "zebra" was traditionally pronounced with a long initial vowel, but over the course of the 20th century the pronunciation with the short initial vowel became the norm in the UK and the
Commonwealth A commonwealth is a traditional English term for a political community founded for the common good. Historically, it has been synonymous with "republic". The noun "commonwealth", meaning "public welfare, general good or advantage", dates from the ...
. The pronunciation with a long initial vowel remains standard in US English.


Taxonomy

Zebras are classified in the genus ''
Equus Equus may refer to: * ''Equus'' (genus), a genus of animals including horses, donkeys and zebras * ''Equus'' (play), a play by Peter Shaffer * ''Equus'' (film), a film adaptation of the Peter Shaffer play * Equus (comics), a comic book characte ...
'' (known as equines) along with
horses The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million yea ...
and asses. These three groups are the only living members of the family Equidae. The plains zebra and mountain zebra were traditionally placed in the
subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...
''Hippotigris'' (C. H. Smith, 1841) in contrast to the
Grévy's zebra Grévy's zebra (''Equus grevyi''), also known as the imperial zebra, is the largest living wild equid and the most threatened of the three species of zebra, the other two being the plains zebra and the mountain zebra. Named after Jules Grévy, i ...
which was considered the sole species of subgenus ''Dolichohippus'' (Heller, 1912). Groves and Bell (2004) placed all three species in the subgenus ''Hippotigris''. A 2013 phylogenetic study found that the plains zebra is more closely related to Grévy's zebras than mountain zebras. The extinct quagga was originally classified as a distinct species. Later genetic studies have placed it as the same species as the plains zebra, either a subspecies or just the southernmost population. Molecular evidence supports zebras as a
monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...
lineage Lineage may refer to: Science * Lineage (anthropology), a group that can demonstrate its common descent from an apical ancestor or a direct line of descent from an ancestor * Lineage (evolution), a temporal sequence of individuals, populati ...
. ''Equus'' originated in North America and direct paleogenomic sequencing of a 700,000-year-old middle Pleistocene horse metapodial bone from Canada implies a date of 4.07 million years ago (mya) for the most recent common ancestor of the equines within the range of 4.0 to 4.5 mya. Horses split from asses and zebras around this time and equines colonised Eurasia and Africa around 2.1–3.4 mya. Zebras and asses diverged from each other close to 2 mya. The mountain zebra diverged from the other species around 1.6 mya and the plains and Grévy's zebra split 1.4 mya. The cladogram of ''Equus'' below is based on Vilstrup and colleagues (2013) and Jónsson and colleagues (2014):


Extant species


Fossil record

In addition to the three living species, some fossil zebras and relatives have also been identified. ''Equus koobiforensis'' is an early equine
basal Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''. Science * Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure * Basal (medicine), a minimal level that is nec ...
to zebras found in the Shungura Formation, Ethiopia and the Olduvai Gorge, Tanzania, and dated to around 2.3 mya. ''E. oldowayensis'' is identified from remains in Olduvai Gorge dating to 1.8 mya. Fossil skulls of ''E. mauritanicus'' from Algeria which date to around 1 mya appears to show affinities with the plains zebra. '' E. capensis'', known as the Cape zebra, appeared around 2 mya and lived throughout southern and eastern Africa. Non-African equines that may have been basal to zebras include ''E. sansaniensis'' of Eurasia (circa 2.5 mya) and '' E. namadicus'' (circa 2.5 mya) and '' E. sivalensis'' (circa 2.0 mya) of the Indian subcontinent. A 2017 mitochondrial DNA study placed the Eurasian ''E. ovodovi'' and the subgenus ''Sussemionus'' lineage as closer to zebras than to asses.


Hybridisation

Fertile hybrids have been reported in the wild between plains and Grévy's zebra. Hybridisation has also been recorded between the plains and mountain zebra, though it is possible that these are infertile due to the difference in chromosome numbers between the two species. Captive zebras have been bred with horses and donkeys; these are known as
zebroids A zebroid is the offspring of any cross between a zebra and any other equine to create a hybrid. In most cases, the sire is a zebra stallion. Offspring of a donkey sire and zebra dam are called a donkra and offspring of a horse sire and a zebr ...
. A zorse is a cross between a zebra and a horse; a zonkey between a zebra and a donkey and a zoni between a zebra and a pony. Zebroids are often born sterile with
dwarfism Dwarfism is a condition wherein an organism is exceptionally small, and mostly occurs in the animal kingdom. In humans, it is sometimes defined as an adult height of less than , regardless of sex; the average adult height among people with dw ...
.


Characteristics

As with all wild equines, zebra have barrel-chested bodies with tufted tails, elongated faces and long necks with long, erect manes. Their thin legs are each supported by a spade-shaped toe covered in a hard hoof. Their
dentition Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiolo ...
is adapted for grazing; they have large incisors that clip grass blades and rough molars and premolars well suited for grinding. Males have spade-shaped canines, which can be used as weapons in fighting. The eyes of zebras are at the sides and far up the head, which allows them to look over the tall grass while feeding. Their moderately long, erect ears are movable and can locate the source of a sound. Unlike horses, zebras and asses have chestnut callosities present only on their front legs. In contrast to other living equines, zebra have longer front legs than back legs. Diagnostic traits of the zebra skull include: its relatively small size with a straight dorsal outline, protruding eye sockets, narrower rostrum, less conspicuous postorbital bar, separation of the
metaconid Many different terms have been proposed for features of the tooth crown in mammals. The structures within the molars receive different names according to their position and morphology. This nomenclature was developed by Henry Fairfield Osborn ...
and metastylid of the tooth by a V-shaped canal and rounded enamel wall.


Stripes

Zebras are easily recognised by their bold black-and-white striping patterns. The
coat A coat typically is an outer garment for the upper body as worn by either gender for warmth or fashion. Coats typically have long sleeves and are open down the front and closing by means of buttons, zippers, hook-and-loop fasteners, toggles, a ...
appears to be white with black stripes, as indicated by the belly and legs when unstriped, but the skin underneath is black. Young or
foal A foal is an equine up to one year old; this term is used mainly for horses, but can be used for donkeys. More specific terms are colt for a male foal and filly for a female foal, and are used until the horse is three or four. When the foal i ...
s are born with brown and white coats, and the brown darkens with age. A dorsal line acts as the backbone for vertical stripes along the sides, from the head to the rump. On the snout they curve toward the nostrils, while the stripes above the front legs split into two branches. On the rump, they develop into species-specific patterns. The stripes on the legs, ears and tail are separate and horizontal. Striping patterns are unique to an individual and heritable. During
embryonic development An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm ...
, the stripes appear at eight months, but the patterns may be determined at three to five weeks. For each species there is a point in embryonic development where the stripes are perpendicular to the dorsal line and spaced apart. However, this happens at three weeks of development for the plains zebra, four weeks for the mountain zebra, and five for Grévy's zebra. The difference in timing is thought to be responsible for the differences in the striping patterns of the different species. Various abnormalities of the patterns have been documented in plains zebras. In
melanistic The term melanism refers to black pigment and is derived from the gr, μελανός. Melanism is the increased development of the dark-colored pigment melanin in the skin or hair. Pseudomelanism, also called abundism, is another variant of pi ...
zebras, dark stripes are highly concentrated on the torso but the legs are whiter. "Spotted" individuals have broken up black stripes around the dorsal area. There have even been morphs with white spots on dark backgrounds. Striping abnormalities have been linked to inbreeding. Albino zebras have been recorded in the forests of
Mount Kenya Mount Kenya (Kikuyu: ''Kĩrĩnyaga'', Kamba, ''Ki Nyaa'') 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 locat ...
, with the dark stripes being blonde. The quagga had brown and white stripes on the head and neck, brown upper parts and a white belly, tail and legs.


Function

The function of stripes in zebras has been discussed among biologists since at least the 19th century. Popular hypotheses include the following: * The
crypsis In ecology, crypsis is the ability of an animal or a plant to avoid observation or detection by other animals. It may be a predation strategy or an antipredator adaptation. Methods include camouflage, nocturnality, subterranean lifestyle and ...
hypothesis suggests that the stripes allow the animal to blend in with its environment or break out its outline so predators can not perceive it as a single entity. This was the earliest hypothesis and proponents argued that the stripes were particularly suited for camouflage in tall grassland and woodland habitat. Alfred Wallace also wrote in 1896 that stripes make zebras less noticeable at night. Zebras graze in open habitat and do not behave cryptically, being noisy, fast, and social. They do not freeze when detecting a predator. In addition, lions and hyenas do not appear to perceive the stripes when they are certain distance away during daytime, thus making the stripes useless in disrupting the outline. Stripes also do not appear to make zebras more difficult to find than more solidly coloured animals of similar size, and predators may still be able to detect them by scent or hearing. The camouflaging stripes of woodland living ungulates like bongos and bushbucks are much less vivid with less contrast with the background colour. In addition, unlike tiger stripes, the spatial frequencies of zebra stripes do not line up with their environment. A 2014 study of wild equine species and subspecies could not find any correlations between striping patterns and woodland habitats. Zebras being less noticeable at night than other prey animals is not supported by modern experiments. * The confusion hypothesis states that the stripes confuse predators, be it by: making it harder to distinguish individuals in a group as well as determining the number of zebras in a group; making it difficult to determine an individual's outline when the group runs away; reducing a predator's ability to keep track of a target during a chase; dazzling an assailant so they have difficulty making contact; or making it difficult for a predator to deduce the zebra's size, speed and direction via
motion dazzle Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...
. This theory has been proposed by several biologists since at least the 1970s. A 2014 computer study of zebra stripes found that they may create a wagon-wheel effect and/or barber pole illusion when in motion. The researchers concluded that this could be used against mammalian predators or biting flies. The use of the stripes for confusing mammalian predators has been questioned. The stripes of zebras could make groups seem smaller, and thus more likely to be attacked. Zebras also tend to scatter when fleeing from attackers and thus the stripes could not break up an individual's outline. Lions, in particular, appear to have no difficulty targeting and catching zebras when they get close and take them by ambush. In addition, no correlations have been found between the amount of stripes and populations of mammal predators. Hughes and colleagues (2021) concluded that solidly grey and less contrasted patterns are more likely to escape being caught when in motion. * The aposematic hypothesis suggests that the stripes serve as warning colouration. This hypothesis was first suggested by Wallace in 1867 and discussed in more detail by Edward Bagnall Poulton in 1890. As with known aposematic mammals, zebras are recognisable up close, live in more open environments, have a high risk of predation and do not hide or act inconspicuous. However they are frequently preyed on by lions, suggesting that stripes do not work on them but may on smaller predators, and are not slow-moving enough to need to ward off threats. They also do not possess adequate defenses to back up the warning pattern. * The social function hypothesis states that stripes serve a role in intraspecific or individual recognition, social bonding, mutual grooming or a signal of fitness. Charles Darwin wrote in 1871 that "a female zebra would not admit the addresses of a male ass until he was painted so as to resemble a zebra" while Wallace stated in 1871 that: "The stripes therefore may be of use by enabling stragglers to distinguish their fellows at a distance". Regarding species and individual identification, zebras have limited range overlap with each other and horses can recognise each other using visual communication. In addition, no correlation has been found between striping and social behaviour or group numbers among equines, and no link has been found between fitness and striping. * The thermoregulatory hypothesis suggests that stripes help to control a zebra's body temperature. In 1971, biologist H. A. Baldwin noted that heat would be absorbed by the black stripes and reflected by the white ones. In 1990, zoologist Desmond Morris suggested that the stripes create cooling convection currents. A 2019 study supported this, finding that where the faster air currents of the warmer black stripes meet those of the white, air swirls form. The researchers also concluded that during the hottest times of the day, zebras erect the black hair to release heat from the skin and flatten it to retain heat when it gets cooler. Larison and colleagues (2015) determined that environmental temperature is a strong predictor for zebra striping patterns. Others have found no evidence that zebras have lower body temperatures than other ungulates whose habitat they share, or that striping correlates with temperature. A 2018 experimental study which dressed water-filled metal barrels in horse, zebra and cattle hides concluded that the zebra stripes had no effect on thermoregulation. * The fly protection hypothesis holds that the stripes deter blood-sucking flies. Horse flies, in particular, spread diseases that are lethal to equines such as African horse sickness, equine influenza, equine infectious anemia and trypanosomiasis. In addition, zebra hair is about as long as the mouthparts of these flies. This hypothesis is the most strongly supported by the evidence. It was found that flies preferred landing on solidly coloured surfaces over those with black-and-white striped patterns in 1930 by biologist R. Harris, and this was proposed to have been a function of zebra stripes in a 1981 study. A 2014 study found a correlation between striping and overlap with horse and
tsetse fly Tsetse ( , or ) (sometimes spelled tzetze; also known as tik-tik flies), are large, biting flies that inhabit much of tropical Africa. Tsetse flies include all the species in the genus ''Glossina'', which are placed in their own family, Glo ...
populations and activity. Other studies have found that zebras are rarely targeted by these insect species. Caro and colleagues (2019) studied captive zebras and horses and observed that neither could deter flies from a distance, but zebra stripes kept flies from landing, both on zebras and horses dressed in zebra
print Printing is the process for reproducing text and images using a master form or template Print or printing may also refer to: Publishing * Canvas print, the result of an image printed onto canvas which is often stretched, or gallery-wrapped, o ...
coats. There does not appear to be any difference in the effectiveness of repelling flies between the different zebra species; thus the difference in striping patterns may have evolved for other reasons. White or light stripes painted on dark bodies have also been found to reduce fly irritations in both cattle and humans. How the stripes repel flies is less clear. A 2012 study concluded that they disrupt the polarised light patterns these insects use to locate water and habitat, though subsequent studies have refuted this. Stripes do not appear to work like a barber pole against flies since checkered patterns also repel them. There is also little evidence that zebra stripes confuse the insects via aliasing. Takács and colleagues (2022) suggest that, when the animal is in sunlight, temperature gradients between the warmer dark stripes and cooler white stripes prevent horseflies from detecting the warm blood vessels underneath. Caro and colleagues (2023) conclude that the insects are confused by the high colour contrast and relative thinness of the patterns.


Ecology and behaviour

Zebras may travel or
migrate Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...
to wetter areas during the dry season. Plains zebras have been recorded travelling between Namibia and Botswana, the longest land migration of mammals in Africa. When migrating, they appear to rely on some memory of the locations where foraging conditions were best and may predict conditions months after their arrival. Plains zebras are more water-dependent and live in moister environments than other species. They usually can be found from a water source. Grévy's zebras can survive almost a week without water but will drink it every day when given the chance, and their bodies maintain water better than cattle. Mountain zebras can be found at elevations of up to . Zebras sleep for seven hours a day, standing up during the day and lying down during the night. They regularly use various objects as rubbing posts and will roll on the ground. A zebra's diet is mostly grasses and sedges, but they will opportunistically consume
bark Bark may refer to: * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Places * Bark, Germany * Bark, Warmian-Masurian Voivodeship, Poland Arts, ...
, leaves, buds, fruits, and roots. Compared to ruminants, zebras have a simpler and less efficient digestive system. Nevertheless, they can subsist on lower-quality vegetation. Zebras may spend 60–80% of their time feeding, depending on the availability of vegetation. The plains zebra is a pioneer grazer, mowing down the upper, less nutritious grass canopy and preparing the way for more specialised grazers, which depend on shorter and more nutritious grasses below. Zebras are preyed on mainly by lions. Leopards, cheetahs, spotted hyenas,
brown hyena The brown hyena (''Parahyaena brunnea''), also called strandwolf, is a species of hyena found in Namibia, Botswana, western and southern Zimbabwe, southern Mozambique and South Africa. It is the only extant species in the genus ''Parahyaena''. It ...
s and wild dogs pose less of a threat to adults. Nile crocodiles also prey on zebras when they near water. Biting and kicking are a zebra's defense tactics. When threatened by lions, zebras flee, and when caught they are rarely effective in fighting off the big cats. In one study, the maximum speed of a zebra was found to be while a lion was measured at . Zebras do not escape lions by speed alone but by sideways turning, especially when the cat is close behind. With smaller predators like hyenas and dogs, zebras may act more aggressively, especially in defense of their young.


Social structure

Zebra species have two basic social structures. Plains and mountain zebras live in stable, closed family groups or harems consisting of one
stallion A stallion is a male horse that has not been gelded (castrated). Stallions follow the conformation and phenotype of their breed, but within that standard, the presence of hormones such as testosterone may give stallions a thicker, "cresty" nec ...
, several
mares A mare is an adult female horse or other equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more than four y ...
, and their offspring. These groups have their own
home ranges A home range is the area in which an animal lives and moves on a periodic basis. It is related to the concept of an animal's territory which is the area that is actively defended. The concept of a home range was introduced by W. H. Burt in 1943. He ...
, which overlap, and they tend to be nomadic. Stallions form and expand their harems by recruiting young mares from their natal (birth) harems. The stability of the group remains even when the family stallion is displaced. Plains zebras groups gather into large herds and may create temporarily stable subgroups within a herd, allowing individuals to interact with those outside their group. Females in harems can spend more time feeding, and gain protection both for them and their young. The females have a linear dominance hierarchy with the high-ranking females being the ones that have lived in the group longest. While traveling, the most dominant females and their offspring lead the group, followed by the next most dominant. The family stallion trails behind. Young of both sexes leave their natal groups as they mature; females are usually herded by outside males to become part of their harems. In the more arid-living Grévy's zebras, adults have more fluid associations and adult males establish large territories, marked by dung piles, and mate with the females that enter them. Grazing and drinking areas tend to be separated in these environments and the most dominant males establish territories near watering holes, which attract females with dependent foals and those who simply want a drink, while less dominant males control territories away from water with more vegetation, and only attract mares without foals. Mares may travel through several territories but remain in one when they have young. Staying in a territory offers a female protection from harassment by outside males, as well as access to resources. In all species, excess males gather in
bachelor group A bachelor herd is a herd of (usually) juvenile male animals who are still sexually immature or 'harem'-forming animals who have been thrown out of their parent groups but not yet formed a new family group. It may also refer to a group of males who ...
s. These are typically young males that are not yet ready to establish a harem or territory. With the plains zebra, the oldest males are the most dominant and group membership is stable. Bachelor groups tend to be at the boundaries of herds and during group movements, the bachelors follow behind or along the sides. Mountain zebra bachelor groups may also include young females that have left their natal group early, as well as old, former harem males. A territorial Grévy's zebra stallion may allow non-territorial bachelors in their territory, however when a mare in
oestrous The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous p ...
is present the territorial stallion keeps other stallions at bay. Bachelors prepare for their future harem roles with play fights and greeting/challenge rituals, which make up most of their activities. Fights between males usually occur over mates and involve biting and kicking. In plains zebra, stallions fight each other over recently matured mares to bring into their group and her family stallion will fight off other males trying to abduct her. As long as a harem stallion is healthy, he is not usually challenged. Only unhealthy stallions have their harems taken over, and even then, the new stallion slowly takes over, peacefully displacing the old one. Agonistic behaviour between male Grévy's zebras occurs at the border of their territories.


Communication

Zebras produce a number of vocalisations and noises. The plains zebra has a distinctive, barking contact call heard as "a-''ha'', a-''ha'', a-''ha''" or "kwa-ha, kaw-ha, ha, ha". The mountain zebra may produce a similar sound while the call of the Grévy's zebra has been described as "something like a hippo's grunt combined with a donkey's wheeze". Loud snorting and rough "gasping" in zebras signals alarm. Squealing is usually made when in pain, but can also be heard in friendly interactions. Zebras also communicate with visual displays, and the flexibility of their lips allows them to make complex facial expressions. Visual displays also consist of head, ear, and tail postures. A zebra may signal an intention to kick by dropping back its ears and whipping its tail. Flattened ears, bared teeth and a waving head may be used as threatening gestures by stallions. Individuals may greet each other by rubbing and sniffing and then mutually rub their cheeks, and move along their bodies towards each other's genitals to sniff. They then may caress their shoulders against each other and lay their heads on one another. This greeting usually occurs between harem or territorial males or among bachelor males playing. Plains and mountain zebras strengthen their social bonds with grooming. Members of a harem nibble and rake along the neck, shoulder, and back with their teeth and lips. Grooming usually occurs between mothers and foals and between stallions and mares. Grooming establishes social rank and eases aggressive behaviour, although Grévy's zebras generally do not perform social grooming.


Reproduction and parenting

Among plains and mountain zebras, the adult females mate only with their harem stallion, while in Grévy's zebras, mating is more promiscuous and the males have larger testes for sperm competition. Female zebras have five to ten day long oestrous cycles; physical signs include a swollen, everted (inside out) labia and copious flows of urine and mucus. Among reaching peak oestrous, mares spread-out their legs, lift their tails and open their mouths when in the presence of a male. Males assess the female's reproductive state with a curled lip and bared teeth ( flehmen response) and the female will solicit mating by backing in. Gestation is typically around a year. A few days to a month later, mares can return to oestrus. In harem-holding species, oestrus in a female becomes less noticeable to outside males as she gets older, hence competition for older females is virtually nonexistent. Usually, a single foal is born, which is capable of running within an hour of birth. A newborn zebra will follow anything that moves, so new mothers prevent other mares from approaching their foals as they become more familiar with the mother's striping pattern, smell and voice. At a few weeks old, foals begin to graze, but may continue to nurse for eight to thirteen months. Living in an arid environment, Grévy's zebras have longer nursing intervals and young only begin to drink water three months after birth. In plains and mountain zebras, foals are cared for mostly by their mothers, but if threatened by pack-hunting hyenas and dogs, the entire group works together to protect all the young. The group forms a protective front with the foals in the centre, and the stallion will rush at predators that come too close. In Grévy's zebras, young stay in " kindergartens" when their mothers leave for water. These groups are tended to by the territorial male. A stallion may look after a foal in his territory to ensure that the mother stays, though it may not be his. By contrast, plains zebra stallions are generally intolerant of foals that are not theirs and may practice
infanticide Infanticide (or infant homicide) is the intentional killing of infants or offspring. Infanticide was a widespread practice throughout human history that was mainly used to dispose of unwanted children, its main purpose is the prevention of reso ...
and feticide via violence to the pregnant mare.


Human relations


Cultural significance

With their distinctive black-and-white stripes, zebras are among the most recognisable mammals. They have been associated with beauty and grace, with naturalist Thomas Pennant describing them in 1781 as "the most elegant of quadrupeds". Zebras have been popular in photography, with some wildlife photographers describing them as the most photogenic animal. They have become staples in children's stories and wildlife-themed art, such as depictions of Noah's Ark. In children's alphabet books, the animals are often used to represent the letter 'Z'. Zebra stripes are also popularly used for body paintings, dress, furniture and architecture. Zebras have been featured in African art and culture for millennia. They are depicted in
rock art In archaeology, rock art is human-made markings placed on natural surfaces, typically vertical stone surfaces. A high proportion of surviving historic and prehistoric rock art is found in caves or partly enclosed rock shelters; this type also ...
in Southern Africa dating from 28,000 to 20,000 years ago, though less often than antelope species like
eland Eland may refer to: Animals *''Taurotragus'', a genus of antelope ** Common eland of East and Southern Africa ** Giant eland of Central and Western Africa Places * Eland, Wisconsin, United States * An old spelling of Elland, West Yorkshire * Ela ...
. How the zebra got its stripes has been the subject of
folk tales Oral literature, orature or folk literature is a genre of literature that is spoken or sung as opposed to that which is written, though much oral literature has been transcribed. There is no standard definition, as anthropologists have used vary ...
, some of which involve it being scorched by fire. The Maasai proverb "a man without culture is like a zebra without stripes" has become popular in Africa. The San people connected zebra stripes with water, rain and lighting, and
water spirit A water spirit is a kind of supernatural being found in the folklore of many cultures: African Some water spirits in traditional African religion include: * Mami Wata is a transcultural pantheon of water spirits and deities of the African dias ...
s were conceived of having these markings. For the Shona people, the zebra is a totem animal and is glorified in a poem as an "iridescent and glittering creature". Its stripes have symbolised the union of male and female and at the ruined city of
Great Zimbabwe Great Zimbabwe is a medieval city in the south-eastern hills of Zimbabwe near Lake Mutirikwi and the town of Masvingo. It is thought to have been the capital of a great kingdom during the country's Late Iron Age about which little is known. Con ...
, zebra stripes decorate what is believed to be a ''domba'', a school meant to prepare girls for adulthood. In the
Shona language Shona (; sn, chiShona) is a Bantu language of the Shona people of Zimbabwe. It was codified by the colonial government in the 1950s. According to ''Ethnologue'', Shona, comprising the Zezuru, Korekore and Karanga dialects, is spoken by about 7 ...
, the name ''madhuve'' means "woman/women of the zebra totem" and is a name for girls in Zimbabwe. The plains zebra is the national animal of Botswana and zebras have been depicted on stamps during
colonial Colonial or The Colonial may refer to: * Colonial, of, relating to, or characteristic of a colony or colony (biology) Architecture * American colonial architecture * French Colonial * Spanish Colonial architecture Automobiles * Colonial (1920 a ...
and post-colonial Africa. For people of the
African diaspora The African diaspora is the worldwide collection of communities descended from native Africans or people from Africa, predominantly in the Americas. The term most commonly refers to the descendants of the West and Central Africans who were e ...
, the zebra represented the politics of race and identity, being both black and white. In cultures outside of its range, the zebra has been thought of as a more exotic alternative to the horse; the comic book character Sheena, Queen of the Jungle, is depicted riding a zebra and explorer Osa Johnson was photographed riding one. The film '' Racing Stripes'' features a captive zebra ostracised from the horses and ends up being ridden by a rebellious girl. Zebras have been featured as characters in animated films like ''
Khumba ''Khumba'' is a 2013 South African computer-animated comedy film directed and co-produced by Anthony Silverston and written by Silverston and Raffaella Delle Donne. The film stars the voices of Jake T. Austin, Steve Buscemi, Loretta Devine, Lau ...
'', '' The Lion King'' and the ''Madagascar'' films and television series such as '' Zou''. Zebras have been popular subjects for
abstract Abstract may refer to: * ''Abstract'' (album), 1962 album by Joe Harriott * Abstract of title a summary of the documents affecting title to parcel of land * Abstract (law), a summary of a legal document * Abstract (summary), in academic publishi ...
, modernist and surrealist artists. Such art includes Christopher Wood's ''Zebra and Parachute'', Lucian Freud's ''The Painter's Room'' and ''Quince on a Blue Table'' and the various paintings of Mary Fedden and
Sidney Nolan Sir Sidney Robert Nolan (22 April 191728 November 1992) was one of Australia's leading artists of the 20th century. Working in a wide variety of mediums, his oeuvre is among the most diverse and prolific in all of modern art. He is best known ...
. Victor Vasarely depicted zebras as black and white lines and connected in a jigsaw puzzle fashion. Carel Weight's ''Escape of the Zebra from the Zoo during an Air Raid'' was based on a real life incident of a zebra escaping during the bombing of London Zoo and consists of four comic book-like panels. Zebras have lent themselves to products and advertisements, notably for 'Zebra Grate Polish' cleaning supplies by British manufacturer Reckitt and Sons and Japanese pen manufacturer Zebra Co., Ltd.


Captivity

Zebras have been kept in captivity since at least the Roman Empire. In later times, captive zebras have been shipped around the world, often for diplomatic reasons. In 1261, Sultan
Baibars Al-Malik al-Zahir Rukn al-Din Baybars al-Bunduqdari ( ar, الملك الظاهر ركن الدين بيبرس البندقداري, ''al-Malik al-Ẓāhir Rukn al-Dīn Baybars al-Bunduqdārī'') (1223/1228 – 1 July 1277), of Turkic Kipchak ...
of Egypt established an embassy with Alfonso X of Castile and sent a zebra and other exotic animals as gifts. In 1417, a zebra was gifted to the Chinese people by Somalia and displayed before the Yongle Emperor. The fourth
Mughal Mughal or Moghul may refer to: Related to the Mughal Empire * Mughal Empire of South Asia between the 16th and 19th centuries * Mughal dynasty * Mughal emperors * Mughal people, a social group of Central and South Asia * Mughal architecture * Mug ...
emperor
Jahangir Nur-ud-Din Muhammad Salim (30 August 1569 – 28 October 1627), known by his imperial name Jahangir (; ), was the fourth Mughal Emperor, who ruled from 1605 until he died in 1627. He was named after the Indian Sufi saint, Salim Chishti. Ear ...
received a zebra from Ethiopia in 1620 and Ustad Mansur made a painting of it. In the 1670s, Ethiopian Emperor Yohannes I exported two zebras to the Dutch governor of
Jakarta Jakarta (; , bew, Jakarte), officially the Special Capital Region of Jakarta ( id, Daerah Khusus Ibukota Jakarta) is the capital and largest city of Indonesia. Lying on the northwest coast of Java, the world's most populous island, Jakarta ...
. These animals would eventually be given by the Dutch to the Tokugawa Shogunate of Japan. When Queen Charlotte received a zebra as a wedding gift in 1762, the animal became a source of fascination for the people of Britain. Many flocked to see it at its paddock at
Buckingham Palace Buckingham Palace () is a London royal residence and the administrative headquarters of the monarch of the United Kingdom. Located in the City of Westminster, the palace is often at the centre of state occasions and royal hospitality. It ...
. It soon became the subject of humour and satire, being referred to as "The Queen's Ass", and was the subject of an oil painting by George Stubbs in 1763. The zebra also gained a reputation for being ill-tempered and kicked at visitors. In 1882, Ethiopia sent a zebra to French president Jules Grévy, and the species it belonged to was named in his honour. Attempts to domesticate zebras were largely unsuccessful. It is possible that having evolved under pressure from the many large predators of Africa, including early humans, they became more aggressive, thus making domestication more difficult. However, zebras have been
trained Training is teaching, or developing in oneself or others, any skills and knowledge or fitness that relate to specific useful competencies. Training has specific goals of improving one's capability, capacity, productivity and performance. I ...
throughout history. In Rome, zebras are recorded to have pulled chariots during amphitheatre games starting in the reign of Caracalla (198 to 217 AD). In the late 19th century, the zoologist Walter Rothschild trained some zebras to draw a carriage in England, which he drove to Buckingham Palace to demonstrate that it can be done. However, he did not ride on them knowing that they were too small and aggressive. In the early 20th century, German colonial officers in East Africa tried to use zebras for both driving and riding, with limited success.


Conservation

As of 2016–2019, the IUCN Red List of mammals lists the Grévy's zebra as endangered, the mountain zebra as
vulnerable Vulnerable may refer to: General * Vulnerability * Vulnerability (computing) * Vulnerable adult * Vulnerable species Music Albums * ''Vulnerable'' (Marvin Gaye album), 1997 * ''Vulnerable'' (Tricky album), 2003 * ''Vulnerable'' (The Used album) ...
and the plains zebra as near-threatened. Grévy's zebra populations are estimated at less than 2,000 mature individuals, but they are stable. Mountain zebras number near 35,000 individuals and their population appears to be increasing. Plains zebra are estimated to number 150,000–250,000 with a decreasing population trend. Human intervention has fragmented zebra ranges and populations. Zebras are threatened by hunting for their hide and meat, and habitat destruction. They also compete with livestock and have their travelling routes obstruct by fences. Civil wars in some countries have also caused declines in zebra populations. By the early 20th century, zebra skins were being used to make rugs and chairs. In the 21st century, zebras may be taken by trophy hunters as zebra skin rugs sell for $1,000 to $2,000. Trophy hunting was rare among African peoples though the San were known to hunt zebra for meat. The quagga (''E. quagga quagga'') population was hunted by early Dutch settlers and later by
Afrikaner Afrikaners () are a South African ethnic group descended from Free Burghers, predominantly Dutch settlers first arriving at the Cape of Good Hope in the 17th and 18th centuries.Entry: Cape Colony. ''Encyclopædia Britannica Volume 4 Part 2: ...
s to provide meat or for their skins. The skins were traded or used locally. The quagga was probably vulnerable to extinction due to its restricted range, and because they were easy to find in large groups. The last known wild quagga died in 1878. The last captive quagga, a female in Amsterdam's Natura Artis Magistra zoo, lived there from 9 May 1867 until it died on 12 August 1883. The
Cape mountain zebra The Cape mountain zebra (''Equus zebra zebra'') is a subspecies of mountain zebra that occurs in certain mountainous regions of the Western and Eastern Cape provinces of South Africa. It is the smallest of all existing zebra species and also the ...
, a subspecies of mountain zebra, nearly went extinct due to hunting and habitat destruction, with less than 50 individuals left by the 1950s. Protections from
South African National Parks South African National Parks (SANParks) is the body responsible for managing South Africa's national parks. SANParks was formed in 1926, and currently manages 19 parks consisting of , over 3% of the total area of South Africa. Many parks offer ...
allowed the population to rise to 2,600 by the 2010s. Zebras can be found in numerous protected areas. Important areas for the Grévy's zebra include Yabelo Wildlife Sanctuary and Chelbi Sanctuary in Ethiopia and Buffalo Springs, Samburu and Shaba National Reserves in Kenya. The plains zebra inhabitats the Serengeti National Park in Tanzania, Tsavo and Masai Mara in Kenya, Hwange National Park in Zimbabwe, Etosha National Park in Namibia, and
Kruger National Park Kruger National Park is a South African National Park and one of the largest game reserves in Africa. It covers an area of in the provinces of Limpopo and Mpumalanga in northeastern South Africa, and extends from north to south and from ea ...
in South Africa. Mountain zebras are protected in
Mountain Zebra National Park Mountain Zebra National Park is a national park in the Eastern Cape province of South Africa proclaimed in July 1937 for the purpose of providing a nature reserve for the endangered Cape mountain zebra. History In the early 1930s, the Cape ...
, Karoo National Park and Goegap Nature Reserve in South Africa as well as Etosha and Namib-Naukluft Park in Namibia.


See also

* Fauna of Africa *
Lord Morton's mare Lord Morton’s mare was an equid hybrid and once an often-noticed example in the history of evolutionary theory. In 1820, George Douglas, 16th Earl of Morton, F.R.S., reported to the President of the Royal Society that, being desirous of domes ...
* Primitive markings – markings found on other equines * Zonkey (Tijuana) – a donkey painted with zebra stripes


Citations


General bibliography

* *


External links


The Quagga Project
An organisation that selectively breeds zebras to recreate the hair coat pattern of the quagga {{Featured article * Equus (genus) Fauna of Sub-Saharan Africa Herbivorous mammals Mammal common names Mammals of Africa