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Zebras (, ) (subgenus ''Hippotigris'') are African equines with distinctive black-and-white striped
coat A coat is typically an outer garment for the upper body, worn by any 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 (AKA velcro), ...
s. There are three
living Living or The Living may refer to: Common meanings *Life, a condition that distinguishes organisms from inorganic objects and dead organisms ** Living species, one that is not extinct *Personal life, the course of an individual human's life * ...
species: Grévy's zebra (''Equus grevyi''), the
plains zebra The plains zebra (''Equus quagga'', formerly ''Equus burchellii'') is the most common and geographically widespread species of zebra. Its range is fragmented, but spans much of southern and eastern Africa south of the Sahara. Six or seven subspec ...
(''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 milli ...
and asses, the three groups being the only living members of the family
Equidae Equidae (commonly known as the horse family) is the Taxonomy (biology), taxonomic Family (biology), family of Wild horse, horses and related animals, including Asinus, asses, zebra, zebras, and many extinct species known only from fossils. The fa ...
. Zebra stripes come in different patterns, unique to each individual. Several theories have been proposed for the function of these patterns, with most evidence supporting them as a deterrent for biting flies. Zebras inhabit eastern and
southern Africa Southern Africa is the southernmost region of Africa. No definition is agreed upon, but some groupings include the United Nations geoscheme for Africa, United Nations geoscheme, the intergovernmental Southern African Development Community, and ...
and can be found in a variety of habitats such as
savannahs A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the Canopy (forest), canopy does not close. The open canopy allows sufficient li ...
,
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 such as clover, and other herbs. Grasslands occur ...
, woodlands,
shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominance (ecology), dominated by shrubs, often also including grasses, herbaceous plant, herbs, and geophytes. Shrubland may either occur naturally o ...
s, and mountainous areas. Zebras are primarily grazers and can subsist on lower-quality vegetation. They are preyed on mainly by
lion The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'', native to Sub-Saharan Africa and India. It has a muscular, broad-chested body (biology), body; a short, rounded head; round ears; and a dark, hairy tuft at the ...
s, 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, several adult females or mares, and their young or foals; 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 polygynandrous. 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 bodies or appearances. A related term, allogrooming, indicates social grooming between members of the same species. Grooming is a major s ...
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 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 milli ...
and donkeys, zebras have never been completely domesticated. The
International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...
(IUCN) lists Grévy's zebra as
endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...
, the mountain zebra as vulnerable and the plains zebra as
near-threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature (IUCN) as that may be vulnerable to endangerment in the near future, but it does not currently qu ...
. 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 Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
''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 The Iberian Peninsula ( ), also known as Iberia, is a peninsula in south-western Europe. Mostly separated from the rest of the European landmass by the Pyrenees, it includes the territories of peninsular Spain and Continental Portugal, comprisin ...
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 zebra was called ''hippotigris'' ("horse tiger") by the
Greeks Greeks or Hellenes (; , ) are an ethnic group and nation native to Greece, Greek Cypriots, Cyprus, Greeks in Albania, southern Albania, Greeks in Turkey#History, Anatolia, parts of Greeks in Italy, Italy and Egyptian Greeks, Egypt, and to a l ...
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
British English British English is the set of Variety (linguistics), varieties of the English language native to the United Kingdom, especially Great Britain. More narrowly, it can refer specifically to the English language in England, or, more broadly, to ...
. The pronunciation with a long initial vowel remains standard in
American English American English, sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the United States. English is the Languages of the United States, most widely spoken lang ...
.


Taxonomy

Zebras are classified in the genus '' Equus'' (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 milli ...
and asses. These three groups are the only living members of the family
Equidae Equidae (commonly known as the horse family) is the Taxonomy (biology), taxonomic Family (biology), family of Wild horse, horses and related animals, including Asinus, asses, zebra, zebras, and many extinct species known only from fossils. The fa ...
. The
plains zebra The plains zebra (''Equus quagga'', formerly ''Equus burchellii'') is the most common and geographically widespread species of zebra. Its range is fragmented, but spans much of southern and eastern Africa south of the Sahara. Six or seven subspec ...
and mountain zebra were traditionally placed in the
subgenus In biology, a subgenus ( 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 the ge ...
''Hippotigris'' (C. H. Smith, 1841) in contrast to the Grévy's zebra 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 In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...
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 biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...
lineage. ''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 a 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. A 2017 mitochondrial DNA study placed the Eurasian '' Equus ovodovi'' and the subgenus ''Sussemionus'' lineage as closer to zebras than to asses. However, other studies disputed this placement, finding the ''Sussemionus'' lineage basal to the zebra+asses group, but suggested that the ''Sussemionus'' lineage may have received gene flow from zebras. 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. ''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.


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 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 A pony is a type of small horse, usually measured under a specified height at maturity. Ponies often have thicker coats, manes and tails, compared to larger horses, and proportionally shorter legs, wider barrels, heavier , thicker necks and s ...
. Zebroids are often born sterile with
dwarfism Dwarfism is a condition of people and animals marked by unusually small size or short stature. In humans, it is sometimes defined as an adult height of less than , regardless of sex; the average adult height among people with dwarfism is . '' ...
.


Characteristics

As with all wild equines, zebras have barrel-chested bodies with tufted tails, elongated faces and long necks with long, erect
manes In ancient Roman religion, the ''Manes'' (, , ) or ''Di Manes'' are chthonic deities sometimes thought to represent souls of deceased loved ones. They were associated with the '' Lares'', '' Lemures'', '' Genii'', and '' Di Penates'' as deities ...
. 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-physiology ...
is adapted for
grazing In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to free range (roam around) and consume wild vegetations in order to feed conversion ratio, convert the otherwise indigestible (by human diges ...
; 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, zebras 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 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 is typically an outer garment for the upper body, worn by any 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 (AKA velcro), ...
appears to be white with black stripes, as indicated by the belly and legs when unstriped, but the skin 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 (horse), colt for a male foal and filly for a female foal, and are used until the horse is three or four. Whe ...
s are born with brown and white coats, and the brown darkens with age. A
dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...
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 In developmental biology, animal embryonic development, also known as animal embryogenesis, is the developmental stage of an animal embryo. Embryonic development starts with the fertilization of an egg cell (ovum) by a sperm, sperm cell (spermat ...
, 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" 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 Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely genetic distance, related genetically. By analogy, the term is used in human reproduction, but more commonly refers to the genet ...
.
Albino Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and reddish pink or blue eyes. Individuals with the condition are referred to as albinos. Varied use and interpretation of ...
zebras have been recorded in the forests of Mount Kenya, 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 part of a predation strategy or an antipredator adaptation. Methods include camouflage, nocturnality, subterranean life ...
hypothesis suggests that the stripes allow the animal to blend in with its environment or break up its outline. 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. Biologist Tim Caro notes that zebras graze in open habitat and do not behave cryptically, being noisy, fast, and social and do not freeze when a predator is near. In addition, the camouflaging stripes of woodland living ungulates like bongos and bushbucks are much less vivid with less contrast with the background colour. A 1987
Fourier analysis In mathematics, Fourier analysis () is the study of the way general functions may be represented or approximated by sums of simpler trigonometric functions. Fourier analysis grew from the study of Fourier series, and is named after Joseph Fo ...
study concluded that the spatial frequencies of zebra stripes do not line up with their environment, while a 2014 study of wild equine species and subspecies could not find any correlations between striping patterns and woodland habitats. Melin and colleagues (2016) found that
lion The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'', native to Sub-Saharan Africa and India. It has a muscular, broad-chested body (biology), body; a short, rounded head; round ears; and a dark, hairy tuft at the ...
s and hyenas do not appear to perceive the stripes when they are a certain distance away at daytime or nighttime, thus making the stripes useless in blending in except when the predators are close enough by which they could smell or hear their target. They also found that the stripes do not make the zebra less noticeable than solidly coloured herbivores on the open plains. They suggested that stripes may give zebras an advantage in woodlands, as the dark stripes could line up with the outlines of tree branches and other vegetation. * 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. 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. Caro suggests that 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 number of stripes and populations of mammal predators. Hughes and colleagues (2021) disputed the idea of motion dazzle and concluded that moving objects that are solidly grey or have less contrasted patterns are actually more likely to escape being caught. * 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 recognizable up close, live in more open environments, have a high risk of predation and do not hide or act inconspicuous. However, Caro notes that stripes do not work on lions because they frequently prey on zebras, though they may work on smaller predators, and zebras are not slow-moving enough to need to ward off threats. In addition, zebras 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 Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...
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, Caro notes that zebra species 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 and 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 their black hair to release heat from the skin and flatten it again 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, Gloss ...
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 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. The effect even extends to pelts, with zebra pelts being less attractive to flies than unstriped impala pelts. 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 visual distortion or 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 disoriented by the high colour contrast and relative thinness of the patterns.


Behaviour and ecology

Zebras may travel or migrate 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 up to 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
grass Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family (biology), family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and spe ...
es and sedges, but they will opportunistically consume bark, 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 like wildebeest, 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 the 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' ...
s and wild dogs pose less of a threat to adults. 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 behaviour

Zebra species have two basic social structures. Plains and mountain zebras live in stable, closed family groups or harems consisting of one stallion, several mares, and their offspring. These groups have their own home ranges, which overlap, and they tend to be nomadic. Stallions form and expand their harems by herding young mares away from their 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. They have a linear
dominance hierarchy In the zoological field of ethology, a dominance hierarchy (formerly and colloquially called a pecking order) is a type of social hierarchy that arises when members of animal social animal, social groups interact, creating a ranking system. Dif ...
with the high-ranking females having 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 groups. 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 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 father 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 Grévy's zebra has been described as "something like a
hippo The hippopotamus (''Hippopotamus amphibius;'' ; : hippopotamuses), often shortened to hippo (: hippos), further qualified as the common hippopotamus, Nile hippopotamus and river hippopotamus, is a large semiaquatic Mammal, mammal native to su ...
'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 mutually touching and rubbing, sniffing their genitals and resting their heads on their shoulders. 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 polygynandrous and the males have larger testes for
sperm competition Sperm competition is the competitive process between Spermatozoon, spermatozoa of two or more different males to fertility, fertilize the same Egg cell, egg during sexual reproduction. Competition can occur when females have multiple potential m ...
. 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. Upon 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 Kindergarten is a preschool educational approach based on playing, singing, practical activities such as drawing, and social interaction as part of the transition from home to school. Such institutions were originally made in the late 18th cent ...
" 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 being the prevention of re ...
and
feticide Foeticide (British English), or feticide (North American English), is the act of killing a fetus, or causing a miscarriage. Definitions differ between legal and medical applications, whereas in law, feticide frequently refers to a criminal offe ...
via violence to the pregnant mare.


Human relations


Cultural significance

With their distinctive black-and-white stripes, zebras are among the most recognizable mammals. They have been associated with beauty and grace, with naturalist
Thomas Pennant Thomas Pennant (16 December 1798) was a Welsh natural history, naturalist, traveller, writer and antiquarian. He was born and lived his whole life at his family estate, Downing Hall, near Whitford, Flintshire, in Wales. As a naturalist he had ...
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 stripe patterns are popularly used for body paintings, dress, furniture and architecture. Zebras have been featured in
African art African art encompasses modern and historical paintings, sculptures, installations, and other visual cultures originating from indigenous African diaspora, African communities across the African continent. The definition may also include the ar ...
and
culture Culture ( ) is a concept that encompasses the social behavior, institutions, and Social norm, norms found in human societies, as well as the knowledge, beliefs, arts, laws, Social norm, customs, capabilities, Attitude (psychology), attitudes ...
for millennia. They are depicted in
rock art In archaeology, rock arts are 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 al ...
in Southern Africa dating from 28,000 to 20,000 years ago, though less often than antelope species like eland. How the zebra got its stripes has been the subject of folk tales, 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 lightning, and water spirits 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, zebra stripes decorate what is believed to be a ''domba'', a school meant to prepare girls for adulthood. In the
Shona language Shona ( ; ) is a Bantu language spoken by the Shona people of Zimbabwe and Mozambique. The term is variously used to collectively describe all the Central Shonic varieties (comprising Zezuru, Manyika, Korekore and Karanga or Ndau) or specifica ...
, the name ''madhuve'' means "woman/women of the zebra totem" and is a name for girls in
Zimbabwe file:Zimbabwe, relief map.jpg, upright=1.22, Zimbabwe, relief map Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Bots ...
. The plains zebra is the national animal of Botswana and zebras have been depicted on stamps during colonial and post-colonial Africa. For people of the
African diaspora The African diaspora is the worldwide collection of communities descended from List of ethnic groups of Africa, people from Africa. The term most commonly refers to the descendants of the native West Africa, West and Central Africans who were ...
, 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'', '' The Lion King'' and the ''Madagascar'' films and television series such as '' Zou''. Zebras have been popular subjects for abstract,
modernist Modernism was an early 20th-century movement in literature, visual arts, and music that emphasized experimentation, abstraction, and Subjectivity and objectivity (philosophy), subjective experience. Philosophy, politics, architecture, and soc ...
and
surrealist Surrealism is an art movement, art and cultural movement that developed in Europe in the aftermath of World War I in which artists aimed to allow the unconscious mind to express itself, often resulting in the depiction of illogical or dreamlike s ...
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. 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 The Roman Empire ruled the Mediterranean and much of Europe, Western Asia and North Africa. The Roman people, Romans conquered most of this during the Roman Republic, Republic, and it was ruled by emperors following Octavian's assumption of ...
. In later times, captive zebras have been shipped around the world, often for diplomatic reasons. In 1261, Sultan Baibars of
Egypt Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...
established an embassy with
Alfonso X of Castile Alfonso X (also known as the Wise, ; 23 November 1221 – 4 April 1284) was King of Castile, Kingdom of León, León and Kingdom of Galicia, Galicia from 1 June 1252 until his death in 1284. During the April 1257 Imperial election, election of 1 ...
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 emperor
Jahangir Nur-ud-din Muhammad Salim (31 August 1569 – 28 October 1627), known by his imperial name Jahangir (; ), was List of emperors of the Mughal Empire, Emperor of Hindustan from 1605 until his death in 1627, and the fourth Mughal emperors, Mughal ...
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 (; , Betawi language, Betawi: ''Jakartè''), officially the Special Capital Region of Jakarta (; ''DKI Jakarta'') and formerly known as Batavia, Dutch East Indies, Batavia until 1949, is the capital and largest city of Indonesia and ...
. These animals would eventually be given by the Dutch to the
Tokugawa Shogunate The Tokugawa shogunate, also known as the was the military government of Japan during the Edo period from 1603 to 1868. The Tokugawa shogunate was established by Tokugawa Ieyasu after victory at the Battle of Sekigahara, ending the civil wars ...
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 royal official residence, residence in London, 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 r ...
. 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 George Stubbs (25 August 1724 – 10 July 1806) was an English painter, best known for his paintings of horses. Self-trained, Stubbs learnt his skills independently from other great artists of the 18th century such as Joshua Reynolds and Thoma ...
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 throughout history. In Rome, zebras are recorded to have pulled chariots during
amphitheatre An amphitheatre (American English, U.S. English: amphitheater) is an open-air venue used for entertainment, performances, and sports. The term derives from the ancient Greek ('), from ('), meaning "on both sides" or "around" and ('), meani ...
games starting in the reign of
Caracalla Marcus Aurelius Antoninus (born Lucius Septimius Bassianus, 4 April 188 – 8 April 217), better known by his nickname Caracalla (; ), was Roman emperor from 198 to 217 AD, first serving as nominal co-emperor under his father and then r ...
(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 The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...
of mammals lists Grévy's zebra as
endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...
, the mountain zebra as vulnerable and the plains zebra as
near-threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature (IUCN) as that may be vulnerable to endangerment in the near future, but it does not currently qu ...
. 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 Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
. 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 hunting, 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 Afrikaners 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, 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 allowed the population to rise to 2,600 by the 2010s. Zebras can be found in numerous protected areas. Important areas for Grévy's zebra include Yabelo Wildlife Sanctuary and Chelbi Wildlife Sanctuary, Chelbi Sanctuary in Ethiopia and Buffalo Springs National Reserve, Buffalo Springs, Samburu National Reserve, Samburu and Shaba National Reserve, Shaba National Reserves in Kenya. The plains zebra inhabits 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 in South Africa. Mountain zebras are protected in Mountain Zebra National Park, Karoo National Park and Goegap Nature Reserve in South Africa as well as Etosha and Namib-Naukluft Park in Namibia.


Notes


See also

* Fauna of Africa * Lord Morton's mare * Primitive markings – markings found on other equines * Zonkey (Tijuana) – a donkey painted with zebra stripes


References


General bibliography

* *


External links


The Quagga Project
��An organisation that selectively breeds zebras to recreate the hair coat pattern of the quagga {{Authority control Zebras, * Equus (genus) Fauna of Sub-Saharan Africa Herbivorous mammals Mammals of Africa Extant Pleistocene first appearances Animal subgenera