Zebra

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Zebra

Temporal range: Pleistocene to recent 2–0 
Ma
↓
A herd of plains zebra ("Equus quagga")
A herd of
Ngorongoro Crater in Tanzania
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Perissodactyla
Family: Equidae
Genus: Equus
Subgenus: Hippotigris
C. H. Smith, 1841
Species

†E. capensis
E. grevyi
†E. koobiforensis
†E. mauritanicus
†E. oldowayensis
E. quagga
E. zebra

Modern range of the three living zebra species

Zebras (

grasslands, woodlands, shrublands
, and mountainous areas.

Zebras are primarily

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 promiscuous. Zebras communicate with various vocalisations, body postures and facial expressions. Social grooming
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

domesticated. The International Union for Conservation of Nature (IUCN) lists Grévy's zebra as endangered, the mountain zebra as vulnerable 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.[2][3] 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.[4] In ancient times, the zebra was called hippotigris ("horse tiger") by the Greeks and Romans.[4][5]

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.[6] The pronunciation with a long initial vowel remains standard in American English.[7]

Taxonomy

Further information: Evolution of the horse

Zebras are classified in the genus

monophyletic lineage.[13][17][18]

Equus originated in North America and direct

recent common ancestor of the equines within the range of 4.0 to 4.5 mya.[19] 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.[20]

A 2017 mitochondrial DNA study placed the Eurasian Equus ovodovi and the subgenus Sussemionus lineage as closer to zebras than to asses.[21] 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.[22]

Photograph of a Quagga mare
Quagga mare at London Zoo, 1870, the only specimen photographed alive. This animal was historically considered a separate species but is now considered a subspecies or population of plains zebra.

The cladogram of Equus below is based on Vilstrup and colleagues (2013) and Jónsson and colleagues (2014):[13][20]

Equus
Zebras

Mountain zebra (E. zebra)

Plains zebra (E. quagga)

Grévy's zebra (E. grevyi)

Wild asses

Kiang (E. kiang)

Onager (E. hemionus)

African wild ass (E. africanus)

Horses

Horse (E. ferus caballus)

Przewalski's horse (E. ferus przewalski)

Extant species

Name Description Distribution Subspecies Chromosomes Image
Grévy's zebra (Equus grevyi) Body length of 250–300 cm (98–118 in) with 38–75 cm (15–30 in) tail, 125–160 cm (4.10–5.25 ft) shoulder height and weighs 352–450 kg (776–992 lb);[23] Thin, elongated skull, robust neck and conical ears; narrow striping pattern with concentric rump stripes, white belly and tail base and white line around the ashy muzzle[8][24][25] Eastern Africa including the Horn;[24] arid and semiarid grasslands and shrublands[26] Monotypic[24] 46[26]
Plains zebra (Equus quagga) Body length of 217–246 cm (85–97 in) with 47–56 cm (19–22 in) tail, 110–145 cm (43–57 in) shoulder height and weighs 175–385 kg (386–849 lb);[23] Thick bodied with relatively short legs and an obtusely-shaped skull profile with a protruding forehead and a more recessed nose area;[8][27] broad stripes, horizontal on the rump, with northern populations having more extensive striping while populations further south have whiter legs and bellies and more brown "shadow" stripes. The snout is black.[8][28][29][30] Eastern and
savannahs, grasslands and open woodlands[31]
 6[12] or monotypic[16] 44[32]
Mountain zebra (Equus zebra) Body length of 210–260 cm (83–102 in) with 40–55 cm (16–22 in) tail, 116–146 cm (46–57 in) shoulder height and weighs 204–430 kg (450–948 lb);
eye sockets more circular and positioned farther back, a squarer nuchal crest, dewlap present under neck and compact hooves; stripes intermediate in width between the other species, with gridiron and horizontal stripes on the rump, while the belly is white and the black muzzle is lined with chestnut or orange[33][8][34][26]
 		Southwestern Africa; mountains, rocky uplands and Karoo shrubland[31][33][30] 2[33] 32[26]

Fossil record

A fossil skull of Equus mauritanicu
Fossil skull of Equus mauritanicus

In addition to the three living species, some fossil zebras and relatives have also been identified. Equus koobiforensis is an early equine basal to zebras found in the Shungura Formation, Ethiopia and the Olduvai Gorge, Tanzania, and dated to around 2.3 mya.[35] E. oldowayensis is identified from remains in Olduvai Gorge dating to 1.8 mya.[36] Fossil skulls of E. mauritanicus from Algeria which date to around 1 mya appears to show affinities with the plains zebra.[37][38] E. capensis, known as the Cape zebra, appeared around 2 mya and lived throughout southern and eastern Africa.[39][36] 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.[35]

Hybridisation

Main article: Zebroid

Fertile hybrids have been reported in the wild between plains and Grévy's zebra.

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. Zebroids are often born sterile with dwarfism.[42]

Characteristics

Further information: Equine anatomy
Mounted skeleton of a Grévy's zebra Cranium, complete skeleton, left forefoot frontal, left forefoot side
Skeleton of a Grévy's zebra at the State Museum of Natural History Karlsruhe

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 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.[8][28][34]

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.[34] 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.[43]

Stripes

"Zebra stripes" redirects here. For other uses, see Zebra stripes (disambiguation).
An illustration showing the three living zebra species
Comparative illustration of living zebra species

Zebras are easily recognised by their bold black-and-white striping patterns. The coat appears to be white with black stripes, as indicated by the belly and legs when unstriped, but the skin is black.[44][45][46] Young or foals are born with brown and white coats, and the brown darkens with age.[27][24] 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.[44]

Striping patterns are unique to an individual and heritable.

embryonic development, 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 0.4 mm (0.016 in) 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.[44]

Various abnormalities of the patterns have been documented in plains zebras. In "

Albino zebras have been recorded in the forests of Mount Kenya, with the dark stripes being blonde.[50] The quagga had brown and white stripes on the head and neck, brown upper parts and a white belly, tail and legs.[51]

Function

The function of stripes in zebras has been discussed among biologists since at least the 19th century.[52] Popular hypotheses include the following:

  • The
    spatial frequencies of zebra stripes do not line up with their environment,[54] while a 2014 study of wild equine species and subspecies could not find any correlations between striping patterns and woodland habitats.[55] Melin and colleagues (2016) found that lions 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.[56]
Closeup shot of mountain zebra stripes
Closeup of mountain zebra stripes
  • 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;
    barber pole illusion when in motion. The researchers concluded that this could be used against mammalian predators or biting flies.[58] 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.[59] In addition, no correlations have been found between the amount of stripes and populations of mammal predators.[55] Hughes and colleagues (2021) concluded that solidly grey and less contrasted patterns are more likely to escape being caught when in motion.[60]
  • 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, critics note 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.[61]
  • 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, critics note that zebra species have limited range overlap with each other and horses can recognise each other using visual communication.[62] In addition, no correlation has been found between striping and social behaviour or group numbers among equines,[55] and no link has been found between fitness and striping.[63]
  • The
    convection currents.[64] 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.[65] Larison and colleagues (2015) determined that environmental temperature is a strong predictor for zebra striping patterns.[66] Others have found no evidence that zebras have lower body temperatures than other ungulates whose habitat they share, or that striping correlates with temperature.[67][55] 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.[68]
Comparison of horse fly flight patterns on horses and zebras
Comparison of flight patterns and contact/landings of horse flies around domestic horses (a-c) and plains zebras (d-f).[69]
  • The fly protection hypothesis holds that the stripes deter
    polarised light patterns these insects use to locate water and habitat,[76] though subsequent studies have refuted this.[77][78][79] Stripes do not appear to work like a barber pole against flies since checkered patterns also repel them.[77][80] There is also little evidence that zebra stripes confuse the insects via visual distortion or aliasing.[77] 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.[78] Caro and colleagues (2023) conclude that the insects are disoriented by the high colour contrast and relative thinness of the patterns.[77]

Behaviour and ecology

Mountain zebra dust bathing
Mountain zebra dustbathing in Namibia

Zebras may travel or migrate to wetter areas during the dry season.[27][28] Plains zebras have been recorded travelling 500 km (310 mi) between Namibia and Botswana, the longest land migration of mammals in Africa.[81] 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.[82] Plains zebras are more water-dependent and live in moister environments than other species. They usually can be found 10–12 km (6.2–7.5 mi) from a water source.[27][28][30] 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.[83][24] Mountain zebras can be found at elevations of up to 2,000 m (6,600 ft).[84] 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.[28]

Plains zebras drinking at a river
Plains zebras at Okavango Delta, Botswana

A zebra's diet is mostly

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.[8][28] 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.[85]

Zebras are preyed on mainly by lions.

spotted hyenas, brown hyenas and wild dogs pose less of a threat to adults.[86] 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.[87] In one study, the maximum speed of a zebra was found to be 50 km/h (31 mph) while a lion was measured at 74 km/h (46 mph). Zebras do not escape lions by speed alone but by sideways turning, especially when the cat is close behind.[88] With smaller predators like hyenas and dogs, zebras may act more aggressively, especially in defense of their young.[89]

Social behaviour

See also:
Horse behaviour
A group of six plains zebra
A plains zebra group

Zebra species have two basic social structures. Plains and mountain zebras live in stable, closed family groups or

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.[8][28][90]

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.[28][8] 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.[91] 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.[90][92]

Three Grévy's zebras grazing
Group of Grévy's zebras grazing

In all species, excess males gather 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.[28]

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.[28]

Communication

A pair of Plains zebra facing each other and rubbing heads on the others body
Plains zebras mutually grooming

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".

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.[28]

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.[28] 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,[28][93] although Grévy's zebras generally do not perform social grooming.[24]

Reproduction and parenting

See also: Horse breeding
A pair of Grévy's zebras mating
Captive Grévy's zebras mating

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.[91][94] 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.[28] 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.[27]

Mountain zebra suckling a foal
Mountain zebra suckling a foal

Usually, a single foal is born, which is capable of running within an hour of birth.[8] 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.[24] At a few weeks old, foals begin to graze, but may continue to nurse for eight to thirteen months.[8] Living in an arid environment, Grévy's zebras have longer nursing intervals and young only begin to drink water three months after birth.[95]

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.

feticide via violence to the pregnant mare.[96]

Human relations

Cultural significance

San rock art depicting a zebra
San rock art depicting a zebra

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 stripe patterns are popularly used for body paintings, dress, furniture and architecture.[97]

Zebras have been featured in

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 lighting, and water spirits were conceived of having these markings.[98]

Illustration of a business's "Zebra Stripes" logo
"Zebra Stripes," trademark for the defunct Glen Raven Cotton Mills Company

For 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 zebra represented the politics of race and identity, being both black and white.[99]

In cultures outside of its range, the zebra has been thought of as a more exotic alternative to the horse; the comic book character

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.[100]

Zebras have been popular subjects for abstract, 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. 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.[101]

Captivity

Queen Charlotte
's zebra

Zebras have been kept in captivity since at least the

Tokugawa Shogunate of Japan.[102]

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. 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.[103] In 1882, Ethiopia sent a zebra to French president Jules Grévy, and the species it belonged to was named in his honour.[9]

Walter Rothschild
with a zebra carriage

Attempts to

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.[106] In the early 20th century, German colonial officers in East Africa tried to use zebras for both driving and riding, with limited success.[107]

Conservation

Mountain zebra hide
Mountain zebra hide

As of 2016–2019, the IUCN Red List of mammals lists Grévy's zebra as endangered, the mountain zebra as vulnerable 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.[108][109][110] Civil wars in some countries have also caused declines in zebra populations.[111] 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.[112]

A herd of Grévy's zebras in Samburu National Reserve
Endangered Grévy's zebras in Samburu National Reserve

The

Natura Artis Magistra zoo, lived there from 9 May 1867 until it died on 12 August 1883.[114] 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.[115]

Zebras can be found in numerous protected areas. Important areas for Grévy's zebra include

Namib-Naukluft Park in Namibia.[109][116]

See also

References

  1. ISBN 978-1-4058-8118-0
    .
  2. ^ "Zebra". Online Etymology Dictionary. Retrieved 22 June 2020.
  3. ^ "Zebra". Lexico. Archived from the original on 27 June 2020. Retrieved 25 June 2020.
  4. ^
    S2CID 55004515
    .
  5. ^ Plumb & Shaw 2018, p. 54.
  6. ^ Wells, John (1997). "Our Changing Pronunciation". Transactions of the Yorkshire Dialect Society. XIX: 42–48. Archived from the original on 7 October 2014. Retrieved 6 February 2014.
  7. Cambridge Dictionary
    . Retrieved 26 May 2020.
  8. ^
    ISBN 978-0-7607-1969-5
    .
  9. ^
    ISBN 978-0-8018-7135-1
    .
  10. ^ "Hippotigris". ITIS. Retrieved 31 August 2020.
  11. ^ "Dolichohippus". ITIS. Retrieved 31 August 2020.
  12. ^
    doi:10.1078/1616-5047-00133
    .
  13. ^
    PMID 23437078
    .
  14. ISBN 978-1-4214-0093-8
    .
  15. PMID 17148190
    .
  16. ^
    S2CID 3333849
    .
  17. ^ Forstén, Ann (1992). "Mitochondrial-DNA timetable and the evolution of Equus: of molecular and paleontological evidence" (PDF). Annales Zoologici Fennici. 28: 301–309.
  18. PMID 2832696. Archived from the original
    (PDF) on 28 May 2016. Retrieved 13 November 2015.
  19. S2CID 4318227
    .
  20. ^
    PMID 25453089
    .
  21. PMID 33473722
    .
  22. PMID 35543411
    .
  23. ^ a b c Caro 2016, p. 9.
  24. ^
    JSTOR 3504222
    .
  25. ^ Caro 2016, p. 15.
  26. ^ a b c d Caro 2016, p. 14.
  27. ^
    JSTOR 3503962
    .
  28. ^
    ISBN 978-0-520-08085-0
    .
  29. ^ Caro 2016, pp. 12–13.
  30. ^
    ISBN 978-0-521-84418-5
    .
  31. ^ a b Caro 2016, p. 11.
  32. ^ Caro 2016, p. 13.
  33. ^
    S2CID 253987177
    .
  34. ^
    ISBN 978-84-96553-77-4
    .
  35. ^
    hdl:2158/1157299
    .
  36. ^
    S2CID 84203907
    .
  37. S2CID 87344101
    .
  38. ^ Eisenmann, V. (2008). "Pliocene and Pleistocene equids: palaeontology versus molecular biology". Courier Forschungsinstitut Senckenberg. 256: 71–89.
  39. PMID 31143541
    .
  40. S2CID 18388598
    .
  41. ISBN 978-1-4214-1909-1
    .
  42. Slate.com
    . Retrieved 16 May 2020.
  43. JSTOR 42931011
    .
  44. ^
    doi:10.1111/j.1469-7998.1977.tb04204.x
    .
  45. ^ Langley, Liz (4 March 2017). "Do Zebras Have Stripes On Their Skin?". National Geographic. Archived from the original on 1 August 2020. Retrieved 2 June 2020.
  46. ^ Caro 2016, pp. 14–15.
  47. ^ Caro 2016, pp. 7, 19.
  48. ^
    S2CID 226305574
    .
  49. ^ Caro 2016, p. 20.
  50. ^ "Extremely Rare 'Blonde' Zebra Photographed". National Geographic. 29 March 2019. Archived from the original on 29 March 2019. Retrieved 25 May 2020.
  51. ISBN 978-0-8018-5789-8
    .
  52. ^ Caro 2016, p. 1.
  53. ^ Caro 2016, pp. 2–3, 23, 48, 50.
  54. doi:10.1111/j.1095-8312.1987.tb00442.x
    .
  55. ^
    PMID 24691390
    .
  56. PMID 26799935
    .
  57. ^ Caro 2016, pp. 72–81, 86.
  58. PMID 24368147
    .
  59. ^ Caro 2016, pp. 80, 92.
  60. PMID 33434457
    .
  61. ^ Caro 2016, pp. 55, 57–58, 68.
  62. ^ Caro 2016, pp. 6–7, 139–148, 150.
  63. ^ Caro 2016, p. 150.
  64. ^ Caro 2016, p. 7.
  65. S2CID 196657566
    .
  66. PMID 26064590
    .
  67. ^ Caro 2016, pp. 158–161.
  68. PMID 29921931
    .
  69. ^
    PMID 30785882
    .
  70. ^
    PMID 36329147
    .
  71. ^ Caro 2016, p. 5.
  72. hdl:10520/AJA00128789_3800
    .
  73. ^ Caro 2016, pp. 196–197.
  74. PMID 32214400
    .
  75. PMID 30800379
    .
  76. PMID 22323196
    .
  77. ^
    S2CID 256273744
    .
  78. ^
    PMID 35927437
    .
  79. PMID 27223616
    .
  80. PMID 32811316
    .
  81. doi:10.1017/S0030605314000222
    .
  82. PMID 28539516
    .
  83. ^ Youth, H. (November–December 2004). "Thin stripes on a thin line". Zoogoer. 33. Archived from the original on 26 October 2005.
  84. ISBN 978-0-313-33999-8
    .
  85. ISBN 978-0-521-53687-5
    .
  86. ^ Caro 2016, pp. 61–63.
  87. ^ Caro 2016, p. 61–62.
  88. S2CID 4405091
    .
  89. ^ Caro 2016, pp. 62–63.
  90. ^
    ISBN 978-0-691-08439-8
    .
  91. ^
    ISBN 978-0123808943
    .
  92. doi:10.1093/beheco/arm055
    .
  93. ^ Caro 2016, p. 143.
  94. S2CID 206771095
    .
  95. ^
    S2CID 54252836
    .
  96. ^ Pluháček, J; Bartos, L (2005). "Further evidence for male infanticide and feticide in captive plains zebra, Equus burchelli" (PDF). Folia Zoologica-Praha. 54 (3): 258–262.
  97. ^ Plumb & Shaw 2018, pp. 10–13, 40–41, 134–140, 189.
  98. ^ Plumb & Shaw 2018, pp. 37–44.
  99. ^ Plumb & Shaw 2018, pp. 45–50.
  100. ^ Plumb & Shaw 2018, pp. 167–169, 188, 192–194, 200–201.
  101. ^ Plumb & Shaw 2018, pp. 128–131, 141–149.
  102. ^ Plumb & Shaw 2018, pp. 55–62, 65–66.
  103. ^ Plumb & Shaw 2018, pp. 76–78, 81.
  104. ^ "The Story Of... Zebra and the Puzzle of African Animals". PBS. Retrieved 13 August 2020.
  105. ^ Plumb & Shaw 2018, p. 56.
  106. ^ Young, R. (23 May 2013). "Can Zebras Be Domesticated and Trained?". Slate. Retrieved 4 September 2013.
  107. ISBN 978-0-8047-6588-6
    .
  108. ^ a b Rubenstein, D.; Low Mackey, B.; Davidson, Z. D.; Kebede, F.; King, S. R. B. (2016). "Equus grevyi". IUCN Red List of Threatened Species. 2016. Retrieved 24 May 2020.
  109. ^ a b Gosling, L. M.; Muntifering, J.; Kolberg, H.; Uiseb, K.; King, S. R. B. (2016). "Equus zebra". IUCN Red List of Threatened Species. 2016. Retrieved 24 May 2020.
  110. ^ a b King, S. R. B.; Moehlman, P. D. (2016). "Equus quagga". IUCN Red List of Threatened Species. 2016. Retrieved 24 May 2020.
  111. ISBN 978-2-8317-0647-4
    .
  112. ^ Plumb & Shaw 2018, pp. 41, 132–133.
  113. ISBN 978-0-521-78812-0
    .
  114. ^ Van Bruggen, A. C. (1959). "Illustrated notes on some extinct South African ungulates". South African Journal of Science. 55: 197–200.
  115. PMID 31365543
    .
  116. ^ Hamunyela, Elly (27 March 2017). "The status of Namibia's Hartmann's zebra". Travel News Namibia. Retrieved 9 July 2020.

General bibliography

External links

Wikimedia Commons has media related to Zebras.
Wikisource has the text of the 1911 Encyclopædia Britannica article "Zebra".
  • The Quagga Project—An organisation that selectively breeds zebras to recreate the hair coat pattern of the quagga
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