Overview

Brief Summary

The historical taxonomic treatment of the Plains Zebra is somewhat confusing. The Plains Zebra complex was long known as Equus burchelli, with the extinct form, the Quagga, recognized as a distinct species, E. quagga. Some evidence suggests that the ranges of the Quagga and the Plains Zebra form known as "Burchell's Zebra" (now E. quagga burchelli) overlapped in southern Africa without interbreeding. However, recent genetic analyses of both mitochondrial and nuclear DNA indicates that the genetic variation among extinct and extant Plains Zebras is no greater than that seen among modern breeds of the Domestic Horse (E. caballus). Thus, the Plains Zebra and the extinct Quagga are now treated as belonging to a single species, E. quagga.

Plains Zebras range from northern Kenya to southern Africa, with those in more southern poulations being larger and with less stripe coverage. These zebras are found in tropical, subtropical, and temperate grasslands, steppes, savannas, and woodlands. Only deserts, dense woodlands, and permanent wetlands are avoided. They occur from sea level to 4300 m (on Mount Kenya). They need to drink daily so they are never more than around half a day's travel (5 to 10 km) from a reliable water source.

Plans Zebras are true grazers and are active both day and night. As hindgut fermenters, they require large quantities of food and may spend up to 20 hours per day foraging.

Females give birth to a single offspring after a 12 month gestation period. Foals begin feeding on grass at a month, but continue to nurse for another 5 months. Females become sexually mature at two to three years. Males begin maintaining harems at around five years.

In 2002, there were an estimated 660,000 Plains Zebras. More than 75% of these are Grant's Zebras (E. q. boehmi), including around 200,000 in the Serengeti-Mara ecosystem. Although Plains Zebras appear to be well protected in much of Kenya and Tanzania, over much of their range they are threatened by poaching and habitat loss.

(Rubenstein 2011 and references therein)

  • Rubenstein, D.I. 2011. Plains Zebra (Equus quagga). Pp. 141-142 in: Wilson, D.E. and Mittermeier, R.A., eds. Handbook of the Mammals of the World. Volume 2. Hoofed Mammals. Lynx Edicions, Barcelona.
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Biology

In common with the plains zebra it is likely that quaggas were found in groups, known as harems, consisting of a number of adult females and led by a dominant male (2). Both males and females leave their natal group when they reach sexual maturity; the composition of adult harems is relatively stable over time with strong social bonds between individuals (6). Foals were born year-round although there appeared to be a peak season in early summer, from December to January (2). As with other equid species, the quagga diet consisted primarily of grasses. Herds tended to migrate to longer grass pastures during the day to feed, returning to areas of shorter grass at night where potential predators had less cover (2).
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Description

The quagga roamed the plains of South Africa until the late 19th Century when it became extinct. Once considered a separate species (1), the quagga is now generally accepted as a subspecies of the plain's zebra (3) (4). However, with their dark stripes on the head and neck merging into brown coloured hindquarters (2) and pale legs devoid of stripes (5), quaggas did look quite distinctive compared to the zebras that we recognise today (2). As with other zebra species, the patterns of the stripes were unique to each individual (2).
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Distribution

A native of southern Africa, the quagga used to occur in vast herds in the Karoo regions of Cape Province and the southern part of Orange Free State. It is now extinct. (South Africa's Threatened Wildlife, 1993)

Biogeographic Regions: neotropical (Native )

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Range Description

Plains Zebra range from southern Sudan and southern Ethiopia, east of the Nile River, to southern Angola and northern Namibia and northern South Africa (formerly ranging south of the Orange and Vaal Rivers to the Cape) (Hack et al. 2002; Klingel in press). They are now extinct in two countries in which they formerly occurred: Burundi and Lesotho. There is no information on their status in Angola, where they may also be extinct.

The six morphologically defined subspecies are distributed as follows (following Groves and Bell 2004, and Klingel in press):

E. q. crawshaii(Crawshay’s Zebra) occurs in Zambia, east of the Luangwa River, Malawi, south-eastern Tanzania from Lake Rukwa east to Mahungoi, and Mozambique as far south as the Gorongoza district;

E. q. borensis ranges in north-west Kenya, from Guas ngishu and Lake Baringo, to the Karamoja district of Uganda and south-east Sudan, east of the Nile River to the northern limit of the species at 32°N;

E. q. boehmi (Grant’s Zebra or Boehm's Zebra) is found in Zambia, west of the Luangwa River, west to Kariba, Shaba Province of DR Congo north to Kibanzao Plateau; Tanzania north from Nyangaui and Kibwezi into south-west Uganda, south-west Kenya as far as Sotik, and east Kenya, east of the Rift Valley, into southern Ethiopia and perhaps to the Juba River in Somalia.

E. q. chapmani (Chapman's Zebra) ranges from north-east South Africa, from about 24°S, 31°E, north to Zimbabwe, west into Botswana at about 19°S, 24°E, the Caprivi Strip in Namibia, and southern Angola;

E. q. burchellii (Burchell's Zebra) formerly occurred north of the Vaal/Orange Rivers, extending north-west via southern Botswana to Etosha National Park and the Kaokoveld, south-east to KwaZulu-Natal and Swaziland. It is now extinct in the middle of its range. E.b. antiquorum is now included in this subspecies;

E. q. quagga (Quagga) occurred in the former Cape Province, south of the Orange and Vaal Rivers and west of the Drakensberg. Now extinct.
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Range

Quaggas were found in the Karoo and southern Free State of South Africa. The date of the disappearance of the last wild animal is unknown but the final quagga died at the Artis Magistra Zoo in Amsterdam in 1883 (5).
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Physical Description

Morphology

The quagga (Equus quagga) is recently extinct. It was closely related to horses and zebras. These zebras averaged 53 inches in height and weighed between 500 and 700 pounds. The Quagga was a relative of the Burchell's Zebra, Equus burchelli, and differed mainly in the degree of striping. The Burchell's Zebra has black stripes on a white background, with brownish "shadow" stripes in between. There is much variability in this pattern, and some Burchell's Zebras have virtually unstriped hindquarters. Museum specimens of the Quagga have dark stripes on the head and neck, but further back the stripes become paler and the interspaces darker, until they merge into a plain brownish color. It is also interesting to note that zebra stripes are like human fingerprints -- no two zebras have the same stripe pattern, which makes it easy to identify individuals. (Planet Wildlife, 1993)

Range mass: 250 to 300 kg.

Other Physical Features: endothermic ; bilateral symmetry

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Ecology

Habitat

Quaggas were often found in arid to temperate grasslands, and sometimes wetter pastures.

Terrestrial Biomes: desert or dune ; savanna or grassland

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Habitat and Ecology

Systems
  • Terrestrial
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Habitat and Ecology

Habitat and Ecology
Plains Zebra live in all habitats in Africa from sea level to 4,300 m on Mount Kenya, with the exception of rain forests, deserts, dune forests, and Cape Sclerophyllous vegetation (Duncan 1992; Klingel in press). Plains Zebra are selective grazers, and in the Serengeti Grogan’s (1973) research indicated that Pennisetum mezianum was a preferred species. He compared proportions ingested to their availability in the sward and found that there was significant selection and rejection of grass species.

In several areas, their movements are directly correlated with the availability of water, moving to grazing areas during the rains and concentrating near permanent rivers or pools during the dry season. The Serengeti migratory subpopulation concentrates during the rains from November to May in the Serengeti plains. At the beginning of the dry season in June it migrates to the western and northern parts of the Serengeti National Park and adjacent areas, and into the Mara National Reserve in Kenya (Klingel in press).

Systems
  • Terrestrial
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Previously found in the arid and temperate grasslands of South Africa (2).
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Trophic Strategy

The quagga was a successful grazer though they often competed with the more numerous wildebeest which frequently occurred in the same areas. Quaggas were often the first of the grazers to enter tall grass vegetation or possibly wet pastures. (Skeleton, 1992)

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Life History and Behavior

Behavior

Perception Channels: tactile ; chemical

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Life Expectancy

Average lifespan

Status: captivity:
40.0 years.

Average lifespan

Status: wild:
20.0 years.

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Reproduction

Quaggas were polygynous animals, meaning that there was mature male for each group,or "harem," of females. To become a harem stallion, a male had to abduct fillies in heat one at a time from their father's herds. Fillies began ovulating and advertising estrus by adopting a distinctive posture between one and two years of age. Many stallions gathered around a herd that included an estrus filly and fought for her with the herd stallion, and with each other. This occurred 5 days every month for about a year until the filly finally conceived. Though foals may be born in any month, there was a definite annual birth/mating peak early in December to January, which corresponds to the rain season in East Africa. Mares that were in good condition reproduced at 2-year intervals, having their first foal at 3 to 3.5 years. (Skeleton, 1992)

Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous

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Conservation

Conservation Status

The last Quagga died in the Amsterdam Zoo in Holland on 12 August 1883. The last wild Quagga in South Africa was probably killed by hunters few years before that, perhaps in 1878. (S. Africas Threatened Wildlife, 1993) Though the South African Red Data Book refers to the Quagga as an extinct species, recent evidence has confirmed that it was actually a subspecies of the Burchell's Zebra. The South African Museum in Cape Town has now embarked on a project to selectively breed Burchell's Zebras with minimal striping on their hindquarters, until the same color pattern as the Quagga can be perhaps be re-created.

IUCN Red List of Threatened Species: extinct

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IUCN Red List Assessment


Red List Category
EX
Extinct

Red List Criteria

Version
3.1

Year Assessed
2008

Assessor/s
Hack, M.A., East, R. & Rubenstein, D.I.

Reviewer/s
Moehlman, P.D. (Equid Red List Authority) & Stuart, S.N. (Global Mammal Assessment Team)

Contributor/s

Justification
The true Quagga has been extinct since the end of the 19th century, when the last individual died in the Amsterdam Zoo in 1883.

History
  • 2002
    Extinct
  • 1996
    Extinct
  • 1994
    Extinct
    (Groombridge 1994)
  • 1990
    Extinct
    (IUCN 1990)
  • 1988
    Extinct
    (IUCN Conservation Monitoring Centre 1988)
  • 1986
    Extinct
    (IUCN Conservation Monitoring Centre 1986)
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IUCN Red List Assessment


Red List Category
LC
Least Concern

Red List Criteria

Version
3.1

Year Assessed
2008

Assessor/s
Hack, M.A & Lorenzen, E.

Reviewer/s
Moehlman, P.D. (Equid Red List Authority) & Stuart, S.N. (Global Mammal Assessment Team)

Contributor/s

Justification
Listed as Least Concern as the species as a whole remains widespread, common, and there are no major threats resulting in a range-wide population decline.

History
  • 2002
    Least Concern
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Status

Classified as Extinct (EX) by the IUCN Red List 2007 (1).
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Population

Population
Plains Zebra are locally common throughout their range both in and also outside protected areas (especially in Kenya and Tanzania). Total numbers were estimated at ~660,000 in 2002 (Hack et al. 2002). Over 75% of the world’s Plains Zebra are of the Grant’s subspecies (E. q. boehmi), with some 200,000 in the greater Serengeti/Mara ecosystem; Serengeti National Park supports the world’s single largest Plains Zebra population (151,000) (East 1997; Hack et al. 2002). Current information on total population size is limited. Aerial survey data from Tanzania indicate that there may have been a population decline of approximately 20% from the late 1990s to the mid-2000’s (Hack et al. 2002; TAWIRI/TWCM pers comm. 2008).

The True Quagga subspecies (E. q. quagga) has been extinct since the end of the 19th century (ca. 1883).

Recorded densities of Plains Zebra include 0.9/km² in Kruger National Park (Smuts 1976) and 22/km² in Ngorongoro (ground count) (Klingel 1967).

Population Trend
Stable
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Threats

Major Threats
No major threats appear to be resulting in range-wide population declines, but habitat loss and overhunting are resulting in localized declines in some areas. Although no country within this species’ range is free of either problem, loss of habitat appears to be more of a concern in the southern half of the range, while poaching appears to be more significant in the northern half. Nonetheless, the Plains Zebra is a relatively resilient species that has demonstrated a remarkable ability to recover from population declines when provided with suitable habitat and protection from overhunting (Hack et al. 2002).

The Quagga was driven to extinction in the late 19th century by overhunting and competition with livestock.
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South Africa became renowned for hunting in the 19th Century, and was known as a 'hunters paradise' (5). Many species, including the quagga, were persecuted for sport and to supply the leather trade with unusual hides (5). In addition, on the sparse, dry grasslands of the Karoo, farmers regarded the quagga as a serious competitor for grazing land with introduced sheep and cattle. During this time, the term 'quagga' in Afrikaans was used for all zebras, and this produced confusion; the uniqueness of this particular zebra was not fully recognised until it was too late (5).
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Management

Conservation Actions

Conservation Actions
Plains Zebra occur in numerous protected areas across their range, including the Serengeti National Park (Tanzania), Tsavo and Masaai Mara (Kenya), Hwange National Park (Zimbabwe), Etosha National Park (Namibia), and Kruger National Park (South Africa).

Hack et al. (2002) proposed the following conservation actions for the species: 1) Improve coverage and frequency of monitoring; 2) Improve risk assessment; 3) Quantify and manage genetic diversity both globally and locally; 4) Increase the understanding of the species' basic biology'; and 5) Investigare the economics of alternative utilization stategies.
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Conservation

A plan to 'retrieve' the quagga is now being carried out in South Africa by the Quagga Project (5). Recent genetic studies on several museum samples revealed that the quagga was indeed a subspecies of the plains zebra and not a distinct species (4). This added fresh hope to the idea that selective breeding of particular plains zebras would lead eventually to an animal resembling the long-lost quagga in appearance. Under the guidance of Reinhold Rau, the project began in earnest in 1987 (5), and by 2008, over 25 third generation foals had been successfully reared, with some of these having coat patterns beginning to approximate those of some of the museum quaggas (7). There has been some controversy about this project, for example, some authorities criticize the project for appearing to demonstrate that it is possible to bring an animal back from extinction. However, proponents believe that a high profile project, which involves the return of these zebras to the grasslands where quaggas once roamed, may help to raise awareness of the importance of the fragile Karoo grassland of Southern Africa (8).
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Relevance to Humans and Ecosystems

Benefits

The Quagga was hunted to extinction by hunters and European settlers, who used their skins for grain bags, and prized them for their colors and patterns.

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Wikipedia

Quagga

For other uses, see Quagga (disambiguation).

The quagga (/ˈkwɑːxɑː/ or /ˈkwæɡə/)[2][3][4] (Equus quagga quagga) is an extinct subspecies of the plains zebra that lived in South Africa until the nineteenth century. It was long thought to be a distinct species, but genetic studies have shown it to be the southernmost subspecies of the plains zebra. It is considered particularly close to Burchell's zebra. Its name is derived from its call, which sounds like "kwa-ha-ha".

The quagga is believed to have been around 257 cm (8 ft 5 in) long and 125–135 cm (4 ft 1 in–4 ft 5 in) tall at the shoulder. It was distinguished from other zebras by its limited pattern of primarily brown and white stripes, mainly on the front part of the body. The rear was brown and without stripes, and therefore more horse-like. The distribution of stripes varied considerably between individuals. Little is known about the quagga's behaviour, but it may have gathered into herds of 30–50 individuals. Quaggas were said to be wild and lively, yet were also considered more docile than Burchell's zebra. They were once found in great numbers in the Karoo of Cape Province and the southern part of the Orange Free State in South Africa.

Since Dutch settlement of South Africa began, the quagga was heavily hunted as it competed with domesticated animals for forage. While some individuals were taken to zoos in Europe, breeding programs were not successful. The last wild population lived in the Orange Free State, and the quagga was extinct in the wild by 1878. The last captive specimen died in Amsterdam on 12 August 1883. Only one quagga was ever photographed alive and only 23 skins are preserved today. In 1984, the quagga was the first extinct animal to have its DNA analysed, and the Quagga Project is trying to recreate the phenotype of hair coat pattern and related characteristics by selectively breeding Burchell's zebras.

Taxonomy[edit]

1804 illustration by Samuel Daniell, which was the basis of the subspecies E. q. danielli

The name "quagga" is derived from the Khoikhoi word for zebra and is onomatopoeic, being said to resemble the quagga's call, variously transcribed as "kwa-ha-ha",[5] "kwahaah",[2] or "oug-ga".[6] The name is still used colloquially for the plains zebra.[5] The quagga was originally classified as a distinct species, Equus quagga, in 1778 by Dutch naturalist Pieter Boddaert.[7] Traditionally, the quagga and the other plains and mountain zebras were placed in the subgenus Hippotigris.[8]

There has been much debate over the status of the quagga in relation to the plains zebra. It is poorly represented in the fossil record, and the identification of these fossils is uncertain, as they were collected at a time when the name quagga referred to all zebras.[5] Fossil skulls of Equus mauritanicus from Algeria have been claimed to show affinities with the quagga and the plains zebra, but they may be too badly damaged to allow definite conclusions to be drawn from them.[9] Quaggas have also been identified in cave art attributed to the San.[10] Reginald Innes Pocock was perhaps the first to suggest that the quagga was a subspecies of plains zebra in 1902. As the quagga was scientifically described and named before the plains zebra, the trinomial name for the quagga becomes E. quagga quagga under this scheme, and the other subspecies of plains zebra are placed under E. quagga as well.[9]

Historically, quagga taxonomy was further complicated by the fact that the extinct southernmost population of Burchell's zebra (Equus quagga burchellii, formerly Equus burchellii burchellii) was thought to be a distinct subspecies (also sometimes thought a full species, E. burchellii). The extant northern population, the "Damara zebra", was later named Equus quagga antiquorum, which means that it is today also referred to as E. q. burchellii, after it was realised they were the same taxon. The extinct population was long thought very close to the quagga, since it also showed limited striping on its hind parts.[8] As an example of this, Shortridge placed the two in the now disused subgenus Quagga in 1934.[11] Most experts now suggest that the two subspecies represent two ends of a cline.[12]

The mare in London Zoo, 1870

Different subspecies of plains zebra were recognised as members of Equus quagga by early researchers, though there was much confusion over which species were valid.[13] Quagga subspecies were described on the basis of differences in striping patterns, but these differences were since attributed to individual variation within the same populations.[14] Some subspecies and even species, such as E. q. danielli and Hippotigris isabellinus, were only based on illustrations (iconotypes) of aberrant quagga specimens.[15][16] Some authors have described the quagga as a kind of wild horse rather than a zebra, and one craniometric study from 1980 seemed to confirm its affiliation with the horse (Equus caballus).[12] It has been pointed out that early morphological studies were erroneous; using skeletons from stuffed specimens can be problematical, as early taxidermists sometimes used donkey and horse skulls inside their mounts when the originals were unavailable.[17]

Evolution[edit]

Specimen in the Museum für Naturkunde, Berlin, which has been sampled for DNA

The quagga was the first extinct animal to have its DNA analysed,[18] and this 1984 study launched the field of ancient DNA analysis. It confirmed that the quagga was more closely related to zebras than to horses,[19] with the quagga and mountain zebra (Equus zebra) sharing an ancestor 3–4 million years ago.[18] An immunological study published the following year found the quagga to be closest to the plains zebra.[20] A 1987 study suggested that the mtDNA of the quagga diverged at a range of roughly 2% per million years, similar to other mammal species, and again confirmed the close relation to the plains zebra.[21]

Later morphological studies came to conflicting conclusions. A 1999 analysis of cranial measurements found that the quagga was as different from the plains zebra as the latter is from the mountain zebra.[19] A 2004 study of skins and skulls instead suggested that the quagga was not a distinct species, but a subspecies of the plains zebra.[8] In spite of these findings, many authors subsequently kept the plains zebra and the quagga as separate species.[5]

A genetic study published in 2005 confirmed the subspecific status of the quagga. It showed that the quagga had little genetic diversity, and that it diverged from the other plains zebra subspecies only between 120,000 and 290,000 years ago, during the Pleistocene, and possibly the penultimate glacial maximum. Its distinct coat pattern perhaps evolved rapidly because of geographical isolation and/or adaptation to a drier environment. In addition, plains zebra subspecies tend to have less striping the further south they live, and the quagga was the most southern-living of them all. Other large African ungulates diverged into separate species and subspecies during this period as well, probably because of the same climate shift. The simplified cladogram below is based on the 2005 analysis (some taxa shared haplotypes and could therefore not be differentiated):[19]



Mountain zebra (E. zebra)




Grévy's zebra (E. grevyi)






Quagga (E. q. quagga)



Damara zebra (E. q. antiquorum)-Chapman's zebra (E. q. chapmani)



Damara zebra-Chapman's zebra




Grant's zebra (E. q. boehmi)




Grant's zebra





Description[edit]

Painting of a stallion in Louis XVI's menagerie at Versailles by Nicolas Marechal, 1793

The quagga is believed to have been 257 cm (8 ft 5 in) long and 125–135 cm (4 ft 1 in–4 ft 5 in) tall at the shoulder.[12] Its coat pattern was unique among equids: zebra-like in the front but more like a horse in the rear.[19] It had brown stripes on the head and neck, brown upper parts and a white belly, tail and legs. The stripes were darkest on the head and neck and became gradually lighter further down the body, blending with the reddish brown of the back and flanks, until disappearing along the back. It appears to have had a high degree of polymorphism, with some individuals having almost no stripes and others having patterns similar to the extinct southern population of Burchell's zebra, where the stripes covered most of the body except for the hind parts, legs and belly.[12] It also had a broad dark dorsal stripe on its back. It had a standing mane with brown and white stripes.[6]

The London mare next to a keeper, 1864

The only quagga to have been photographed alive was a mare at the Zoological Society of London's Zoo. Five photographs of this specimen are known, taken between 1863 and 1870.[22] On the basis of photographs and written descriptions, many observers suggest that the stripes on the quagga were light on a dark background, unlike other zebras. Reinhold Rau, pioneer of the Quagga Project, claimed that this is an optical illusion: that the base colour is a creamy white and that the stripes are thick and dark.[12] Embryological evidence supports zebras being dark coloured with white as an addition.[23]

Living in the very southern end of the plains zebra's range, the quagga had a thick winter coat that moulted each year. Its skull was described as having a straight profile and a concave diastema, and as being relatively broad with a narrow occiput.[8][24] Like other plains zebras, the quagga did not have a dewlap on its neck as the mountain zebra does.[9] The 2004 morphological study found that the skeletal features of the southern Burchell's zebra population and the quagga overlapped, and that they were impossible to distinguish. Some specimens also appeared to be intermediate between the two in striping, and individuals of the extant Burchell's zebra population still exhibit limited striping. It can therefore be concluded that the two subspecies graded morphologically into each other. Today, some stuffed specimens of quaggas and southern Burchell's zebra are so similar that they are impossible to definitely identify as either, since no location data was recorded. The female specimens used in the study were larger than the males on average.[8]

Behaviour and ecology[edit]

Live stallion at the Royal College of Surgeons, painted by Jacques-Laurent Agasse in the early 1800s

The quagga was the southernmost distributed plains zebra, mainly living south of the Orange River. It was a grazer, and its habitat range was restricted to the grasslands and arid interior scrubland of the Karoo region of South Africa, today forming parts of the provinces of Northern Cape, Eastern Cape, Western Cape and the Free State.[12][25] These areas were known for distinctive flora and fauna and high amounts of endemism.[24][26]

Little is known about the behaviour of quaggas in the wild, and it is sometimes unclear what exact species of zebra is referred to in old reports.[12] The only source that unequivocally describes the quagga in the Free State is that of the English military engineer and hunter Major Sir William Cornwallis Harris.[8] His 1840 account reads as follows:

The geographical range of the quagga does not appear to extend to the northward of the river Vaal. The animal was formerly extremely common within the colony; but, vanishing before the strides of civilisation, is now to be found in very limited numbers and on the borders only. Beyond, on those sultry plains which are completely taken possession of by wild beasts, and may with strict propriety be termed the domains of savage nature, it occurs in interminable herds; and, although never intermixing with its more elegant congeners, it is almost invariably to be found ranging with the white-tailed gnu and with the ostrich, for the society of which bird especially it evinces the most singular predilection. Moving slowly across the profile of the ocean-like horizon, uttering a shrill, barking neigh, of which its name forms a correct imitation, long files of quaggas continually remind the early traveller of a rival caravan on its march. Bands of many hundreds are thus frequently seen doing their migration from the dreary and desolate plains of some portion of the interior, which has formed their secluded abode, seeking for those more luxuriant pastures where, during the summer months, various herbs thrust forth their leaves and flowers to form a green carpet, spangled with hues the most brilliant and diversified.[27]

Fifth known photo of the London Zoo mare, taken in 1863, rediscovered in 1991

Quaggas have been reported gathering into herds of 30–50 individuals and sometimes travelled in a linear fashion.[12] They may have been sympatric with Burchell's zebra between the Vaal and Orange rivers.[8][26] This is disputed,[8] and there is no evidence that they interbred.[26] It could also have shared a small portion of its range with Hartmann's mountain zebra (Equus zebra hartmannae).[19]

Quaggas were said to be lively and highly strung, especially the stallions. During the 1830s, quaggas were used as harness animals for carriages in London, the males probably being gelded to mitigate their volatile nature.[28] Local farmers used them as guards for their livestock, as they were likely to attack intruders.[29] On the other hand, captive quaggas in European zoos were said to be tamer and more docile than Burchell's zebra.[12] One specimen was reported to have lived in captivity for 21 years and 4 months, dying in 1872.[12]

Since the practical function of striping has not been determined for zebras in general, it is unclear why the quagga lacked stripes on its hind parts. A cryptic function for protection from predators (stripes obscure the individual zebra in a herd) and biting flies (which are less attracted to striped objects), as well as various social functions, have been proposed for zebras in general. Differences in hind quarter stripes may have aided species recognition during stampedes of mixed herds, so that members of one subspecies or species would follow its own kind. It has also been hypothesised that the zebras developed striping patterns as thermoregulation to cool themselves down, and that the quagga lost them due to living in a cooler climate, although one problem with this is that the mountain zebra lives in similar environments and has a bold striping pattern.[30] A 2014 study strongly supported the biting-fly hypothesis, and the quagga appears to have lived in areas with lesser amounts of fly activity compared to other zebras.[31]

Decline and extinction[edit]

Skeleton at the Grant Museum

As it was easy to find and kill, the quagga 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 limited distribution, and it may have competed with domestic livestock for forage.[29] The quagga had disappeared from much of its range by the 1850s. The last population in the wild, in the Orange Free State, was extirpated in the late 1870s.[12] The last known wild individual died in 1878.[29]

Individual quaggas were also captured and shipped to Europe, where they were displayed in zoos.[12] Lord Morton tried to save the animal from extinction by starting a captive breeding program. He was only able to obtain a single male which, in desperation, he bred with a female horse. This produced a female hybrid with zebra stripes on its back and legs. Lord Morton's mare was sold and was subsequently bred with a black stallion, resulting in offspring that again had zebra stripes. An account of this was published in 1820 by the Royal Society.[32] This led to new ideas on telegony, referred to as pan-genesis by Charles Darwin.[25]

The last known quagga and a great auk, in Naturalis, Leiden

The last captive specimen, a female in Amsterdam's Natura Artis Magistra zoo, lived there from 9 May 1867 until it died on 12 August 1883, but its origin and cause of death were not recorded. The specimen in London died in 1872 and the one in Berlin in 1875.[14] There are 23 known stuffed and mounted quagga specimens throughout the world. In addition, there is a mounted head and neck, a foot, seven complete skeletons, and samples of various tissues. A twenty-fourth mounted specimen was destroyed in Königsberg, Germany, during World War II.[33]

Breeding back project[edit]

Main article: Quagga Project

After the very close relationship between the quagga and surviving zebras was discovered, Reinhold Rau started the Quagga Project in 1987 in South Africa to recreate the quagga by selective breeding from plains zebra stock, with the eventual aim of reintroducing them to the wild. To differentiate between the previously existing quagga zebras and the ones bred back into the environment, it has been suggested the new population should be referred to as "Rau quaggas".[25] The founding population consisted of 19 individuals from Namibia and South Africa, chosen because they had reduced striping on the rear body and legs. The first foal of the project was born in 1988. Once a sufficiently quagga-like population has been created, it will be released in the Western Cape.[17]

Introduction of Rau's quaggas could be part of a comprehensive restoration program including such ongoing efforts as eradication of non-native trees. Quaggas, wildebeest, and ostriches, which occurred together during historical times in a mutually beneficial association, could be kept together in areas where the indigenous vegetation has to be maintained by grazing. In early 2006, the third and fourth generation animals produced by the project were reported to look very much like the depictions and preserved specimens of the quagga. This type of selective breeding is called breeding back. The practice is controversial, since the resulting zebras will resemble the quaggas only in external appearance, but will be genetically different. The technology to use recovered DNA for cloning does not exist.[2][34]

See also[edit]

References[edit]

  1. ^ Hack, M. A.; East, R.; Rubenstein, D. I. (2008). Equus quagga quagga. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 5 January 2008.
  2. ^ a b c Max, D. T. (1 January 2006). "Can You Revive an Extinct Animal?". The New York Times. Retrieved 3 March 2014. 
  3. ^ "Rebuilding a Species". VOA. Retrieved 10 April 2014. 
  4. ^ "Oxford Dictionaries". Oxford University Press. Retrieved 13 August 2014. 
  5. ^ a b c d Skinner, J. D.; Chimimba, C. T (2005). "Equidae". The Mammals of the Southern African Subregion (3rd ed.). Cambridge: Cambridge University Press. pp. 537–546. ISBN 0-521-84418-5. 
  6. ^ a b  This article incorporates text from a publication now in the public domainChisholm, Hugh, ed. (1911). "Quagga". Encyclopædia Britannica (11th ed.). Cambridge University Press. 
  7. ^ Groves, C.; Grubb, P. (2011). Ungulate Taxonomy. Johns Hopkins University Press. p. 16. ISBN 1-4214-0093-6. 
  8. ^ a b c d e f g h Groves, C. P.; Bell, C. H. (2004). "New investigations on the taxonomy of the zebras genus Equus, subgenus Hippotigris". Mammalian Biology - Zeitschrift für Säugetierkunde 69 (3): 182. doi:10.1078/1616-5047-00133.  edit
  9. ^ a b c Azzaroli, A.; Stanyon, R. (1991). "Specific identity and taxonomic position of the extinct Quagga". Rendiconti Lincei 2 (4): 425. doi:10.1007/BF03001000.  edit
  10. ^ Ouzman, S.; Taçon, P. S. C.; Mulvaney, K.; Fullager, R. (2002). "Extraordinary Engraved Bird Track from North Australia: Extinct Fauna, Dreaming Being and/or Aesthetic Masterpiece?". Cambridge Archaeological Journal 12: 103. doi:10.1017/S0959774302000057.  edit
  11. ^ Groves, C. P.; Willoughby, D. P. (1981). "Studies on the taxonomy and phylogeny of the genus Equus. 1. Subgeneric classification of the recent species". Mammalia 45 (3). doi:10.1515/mamm.1981.45.3.321.  edit
  12. ^ a b c d e f g h i j k l Nowak, R. M. (1999). Walker's Mammals of the World, Volume 1. Johns Hopkins University Press. pp. 1024–1025. ISBN 0-8018-5789-9. 
  13. ^ St. Leger, J. (1932). "LXVII.—On Equus quagga of South-western and Eastern Africa". Journal of Natural History Series 10 10 (60): 587–593. doi:10.1080/00222933208673614.  edit
  14. ^ a b Van Bruggen, A.C. (1959). "Illustrated notes on some extinct South African ungulates". South African Journal of Science 55: 197–200. 
  15. ^ Schlawe, L.; Wozniak, W. (2010). "Über die ausgerotteten Steppenzebras von Südafrika QUAGGA und DAUW, Equus quagga quagga". Zeitschrift des Kölner Zoos (in German) 2: 97–128. 
  16. ^ Smith, C. H. (1841). "The Natural History of Horses: The Equidae or Genus Equus of Authors". Edinburgh: W.H. Lizars. p. 388. doi:10.5962/bhl.title.21334.  edit
  17. ^ a b Harley, E. H.; Knight, M. H.; Lardner, C.; Wooding, B.; Gregor, M. (2009). "The Quagga Project: Progress over 20 Years of Selective Breeding". South African Journal of Wildlife Research 39 (2): 155. doi:10.3957/056.039.0206.  edit
  18. ^ a b Higuchi, R.; Bowman, B.; Freiberger, M.; Ryder, O. A.; Wilson, A. C. (1984). "DNA sequences from the quagga, an extinct member of the horse family". Nature 312 (5991): 282–284. doi:10.1038/312282a0. PMID 6504142.  edit
  19. ^ a b c d e Hofreiter, M.; Caccone, A.; Fleischer, R. C.; Glaberman, S.; Rohland, N.; Leonard, J. A. (2005). "A rapid loss of stripes: The evolutionary history of the extinct quagga". Biology Letters 1 (3): 291–295. doi:10.1098/rsbl.2005.0323. PMC 1617154. PMID 17148190.  edit
  20. ^ Lowenstein, J. M.; Ryder, O. A. (1985). "Immunological systematics of the extinct quagga (Equidae)". Experientia 41 (9): 1192–1193. doi:10.1007/BF01951724. PMID 4043335.  edit
  21. ^ Higuchi, R. G.; Wrischnik, L. A.; Oakes, E.; George, M.; Tong, B.; Wilson, A. C. (1987). "Mitochondrial DNA of the extinct quagga: Relatedness and extent of postmortem change". Journal of Molecular Evolution 25 (4): 283–287. doi:10.1007/BF02603111. PMID 2822938.  edit
  22. ^ Huber, W. (1994). "Dokumentation der fünf bekannten Lebendaufnahmen vom Quagga, Equus quagga quagga Gmelin, 1788 (Mammalia, Perissodactyla, Equidae)". Spixiana (in German) 17: 193–199. 
  23. ^ Prothero, D. R.; Schoch, R. M. (2003). Horns, Tusks, and Flippers: The Evolution of Hoofed Mammals. Johns Hopkins University Press. p. 221. ISBN 0-8018-7135-2. 
  24. ^ a b Kingdon, J. (1988). East African Mammals: An Atlas of Evolution in Africa, Volume 3, Part B: Large Mammals. University of Chicago Press. p. 139. ISBN 0-226-43722-1. 
  25. ^ a b c Heywood, P. (2013). "The quagga and science: What does the future hold for this extinct zebra?". Perspectives in Biology and Medicine 56 (1): 53–64. doi:10.1353/pbm.2013.0008. PMID 23748526.  edit
  26. ^ a b c Hack, M. A.; East, R.; Rubenstein, D. I. (2002). "Status and Action Plan for the Plains Zebra (Equus burchelli)". In Moehlman, P. D. R. Equids: Zebras, Asses, and Horses: Status Survey and Conservation Action Plan. IUCN/SSC Equid Specialist Group. p. 44. ISBN 2-8317-0647-5. 
  27. ^ Sir Cornwallis Harris, quoted in Duncan, F. M. (1913). Cassell's natural history. London: Cassell. pp. 350–351. Retrieved 22 June 2013. 
  28. ^ Piper, R. (20 March 2009). Extinct animals: an encyclopedia of species that have disappeared during human history. Greenwood Press. ISBN 978-0-313-34987-4. Retrieved 23 June 2013. 
  29. ^ a b c Weddell, B. J. (2002). Conserving Living Natural Resources: In the Context of a Changing World. Cambridge University Press. p. 46. ISBN 0-521-78812-9. 
  30. ^ Ruxton, G. D. (2002). "The possible fitness benefits of striped coat coloration for zebra". Mammal Review 32 (4): 237–244. doi:10.1046/j.1365-2907.2002.00108.x.  edit
  31. ^ Caro, T.; Izzo, A.; Reiner, R. C.; Walker, H.; Stankowich, T. (2014). "The function of zebra stripes". Nature Communications 5. doi:10.1038/ncomms4535.  edit
  32. ^ Birkhead, T. R. (2003). A Brand New Bird: How Two Amateur Scientists Created the First Genetically Engineered Animal. Basic Books. p. 145. ISBN 0-465-00665-5. 
  33. ^ Rau, R. E. (1978). "Additions to the revised list of preserved material of the extinct Cape Colony quagga and notes on the relationship and distribution of southern plains zebras". Annals of the South African Museum 77: 27–45. ISSN 0303-2515. 
  34. ^ Freeman, C. (2009). "Ending Extinction: The Quagga, the Thylacine, and the 'Smart Human'". "Leonardo's Choice". pp. 235–256. doi:10.1007/978-90-481-2479-4_13. ISBN 978-90-481-2478-7.  edit
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Plains zebra

The plains zebra (Equus quagga, formerly Equus burchellii), also known as the common zebra or Burchell's zebra, is the most common and geographically widespread species of zebra.[2] It ranges from the south of Ethiopia through East Africa to as far south as Botswana and eastern South Africa. The plains zebra remains common in game reserves, but is threatened by human activities such as hunting for its meat and hide, as well as competition with livestock and encroachment by farming on much of its habitat.

Subspecies include the extinct quagga and six recognized extant subspecies, though there is great variation in coat patterns between individuals. The striping pattern is unique among ungulates in the region, and its functions are disputed. Suggested functions include crypsis, forms of motion camouflage, social signaling and recognition, and discouraging biting flies.

The plains zebra's range is fragmented but spans much of southern and eastern Africa south of the Sahara. Its habitat is generally but not exclusively treeless grasslands and savanna woodlands, both tropical and temperate. They generally avoid desert, dense rainforest and permanent wetlands, and rarely stray more than 30 kilometers from a water source.

The plains zebra is a highly social species forming harems with a single stallion, several mares and their recent offspring; there are also bachelor groups. Groups may come together to form herds. The animals keep watch for predators rather than attempting to hide; they bark or snort when they see a predator, and the harem stallion attacks predators such as dogs, hyenas and leopards to defend his harem. The species population is stable and not endangered, though some populations such as in Tanzania have declined sharply.

Taxonomy[edit]

There is a dispute among biologists as to how to properly classify the various species of Zebra. It is thought that the plains zebra and mountain zebra belong to the subgenus Hippotigris and that Grévy's zebra is the sole species of subgenus Dolichohippus. This is on account of Grévy's zebra resembling an ass (subgenus Asinus), while the plains zebra and mountain zebra are more horse-like. All three animals belong to the genus Equus along with other living equids. However, recent phylogenetic evidence suggests that the mountain zebras and Grévy's zebras to be classified with asses and donkeys in a lineage separate from the Plains zebra.[3] In areas where Plains zebras are sympatric with Grévy's zebras, it is not unusual to find them in the same herds[4] and fertile hybrids occur.[5] In captivity, Plains zebras have been crossed with mountain zebras. The hybrid foals lacked a dewlap and resembled the plains zebra apart from their larger ears and their hindquarters pattern.

Subspecies[edit]

Quagga (E. q. quagga)
Burchell's zebra (E. q. burchellii) in Etosha National Park, Namibia
Maneless zebras (E. q. borensis) are the northernmost and generally the darkest form of the plains zebra

In 2004, C. P. Groves and C. H. Bell investigated the taxonomy of the zebra genus, Equus, subgenus Hippotigris. They published their research in the journal Mammalian Biology. They revised the subspecies of the plains zebra Equus quagga. Six subspecies are now recognizable.[1]

Sometimes another subspecies is distinguished in Eastern Zimbabwe and Western Mozambique:

The quagga was originally classified as a separate species, Equus quagga, in 1778. Over the next 50 years or so, many other zebras were described by naturalists and explorers. Because of the great variation in coat patterns (no two zebras are alike), taxonomists were left with a great number of described "species", and no easy way to tell which of these were true species, which were subspecies, and which were simply natural variants. The quagga was the first extinct creature to have its DNA studied. Recent genetic research at the Smithsonian Institution has demonstrated that the quagga was in fact not a separate species at all, but diverged from the plains zebra, between 120,000 and 290,000 years ago, and suggests that it should be named Equus burchellii quagga. However, according to the rules of biological nomenclature, where there are two or more alternative names for a single species, the name first used takes priority. As the quagga was described about thirty years earlier than the Burchell's zebra, it appears that the correct terms are E. quagga quagga for the quagga and E. quagga burchellii for the plains zebra, unless "Equus burchellii" is officially declared to be a nomen conservandum.

Burchell's zebra was thought to have been hunted to extinction. However Groves and Bell concluded in their 2004 publication that "the extinct true Burchell's zebra" is a phantom. Careful study of the original zebra populations in Zululand and Swaziland, and of skins harvested on game farms in Zululand and Natal, has revealed that a certain small proportion shows similarity to what now is regarded as typical "burchellii". The type localities of the subspecies Equus quagga burchellii and Equus quagga antiquorum (the Damara zebra) are so close to each other that the two are in fact one, and that therefore the older of the two names should take precedence over the younger. They therefore say that the correct name for the southernmost subspecies must be burchellii not antiquorum. The subspecies Equus quagga burchellii still exists in KwaZulu-Natal and in Etosha.

Physical description[edit]

Foal displaying brown and white pattern
Variation in coat pattern in zebras.

The plains zebra is mid-sized, smaller on average than the other two zebra species, and thick bodied with relatively short legs. There is some variation in size, based on the animals' condition and subspecies. Adults of both sexes can stand from 1.1 to 1.45 m (3.6 to 4.8 ft) high at the withers (shoulder), are 2.2 to 2.5 m (7.2 to 8.2 ft) long, not counting a 50 cm (20 in) tail, and weigh 175 to 385 kg (386 to 849 lb). Males may weigh 10% more than females.[6][7]

Like all zebras, they are boldly striped in black and white, and no two individuals look exactly alike. They also have black or dark muzzles. The natal coat of a foal is brown and white. All have vertical stripes on the forepart of the body, which tend towards the horizontal on the hindquarters. The northern populations have narrower and more defined striping;[8][9] southern populations have varied but lesser amounts of striping on the underparts, the legs and the hindquarters.[8] Southern populations also have brown "shadow" stripes between the black and white coloring.[8][9] These are absent or poorly expressed in northern zebras.[8][9]

Embryological evidence has shown that the zebra's background color is dark and the white is an addition.[10] The first subspecies to be described, the now-extinct quagga, had plain brown hindquarters. There have been various mutations of the zebra's pelage from mostly white to mostly black.[11] Rare albino zebras have been recorded in the forests of Mount Kenya.[12]

Function of the stripes[edit]

The striping pattern of the zebra is unique among sympatric ungulates. One suggested function for the stripes is to provide crypsis for the animal in tall grass or in the dappled shade beneath bushes and trees.[13] However, cryptically colored species like the kudu and bushbuck tend to be quiet and stealthy. They freeze when there is danger and flee only at the last moment. By contrast, the zebra is active and noisy,[13] and makes no attempt to hide itself.[10] Another suggestion is motion camouflage, that the stripes affect a predator's judgement of the zebra's size, distance and what direction it is going in.[13] A 2014 study supports this hypothesis, finding that when moving the stripes may confuse observers, such as mammalian predators and biting insects, via two visual illusions, the wagon wheel effect, where the perceived motion is inverted, and the barber pole illusion, where the perceived motion is in a wrong direction.[14] A related hypothesis is that the stripes make it difficult for a predator to single out and learn about on an individual during a chase.[13] Perhaps the best explanation for the stripes is that they serve a social function.[10] Individual zebras can apparently recognize each other by their striping patterns.[15] The stripes may also serve as visual cues for grooming.[10] In addition, they could serve to help zebra groups stay together when they are fleeing.[13] A 2012 study suggests that stripes may have developed to discourage biting flies. Experiments have demonstrated that the stripes polarize light in such a way that it discourages tabanids (biting flies) in a manner not shown with other coat patterns.[16]

Ecology[edit]

Range and habitat[edit]

Plains zebra are highly dependent on water

The plains zebra's range stops short of the Sahara from South Sudan and southern Ethiopia extending south along eastern Africa, as far as Zambia, Mozambique, and Malawi, before spreading into most southern African countries. They are regionally extinct in Burundi and Lesotho, and they may have lived in Algeria in the Neolithic Era.[17]

Plains zebras generally live in treeless grasslands and savanna woodlands[9] but can be found in a variety of habitats, both tropical and temperate. However they are generally absent from deserts, dense rainforests and permanent wetlands.[9] Zebras also live in elevations from sea level to 4,300 m on Mount Kenya. They rely on rainfall for food and water, and go on great migrations to follow the rains. The zebras will migrate up to 700 miles (1,100 km) for food. Other grazers also migrate. Plains zebras are highly water-dependent[4] and are usually found within 25–30 kilometers of a water source.

Diet and predation[edit]

Zebras grazing with wildebeests in the Ngorongoro Crater

In one study, the zebra's diet was estimated to be 92% grass, 5% herbs, and 3% shrubs.[18] Unlike many of the large ungulates of Africa, the plains zebra does not require (but still prefers) short grass to graze. It eats a wide range of different grasses, preferring young, fresh growth where available, and also browses on leaves and shoots from time to time. In consequence, it ranges more widely than many other species, even into woodlands, and it is often the first grazing species to appear in a well-vegetated area.[4] Zebras have a simple stomach and use hindgut fermentation (caeco-colic) which allows them to digest and assimilate larger amounts of forage during a 24-hour period.[19] Thus, zebras are less selective in foraging, but they do spend much time eating. The zebra is a pioneer grazer and prepares the way for more specialized grazers like blue wildebeests and Thomson's gazelles[4] which depend on shorter and more nutritious grasses.

The plains zebra's major predators are lions and spotted hyenas.[8] Nile crocodiles are also great threats during migratory river crossings. Wild dogs, cheetahs, and leopards also prey on zebras, although the threats they pose are generally minor and they mostly attack the foals. Olive Baboons may prey on foals, but pose no threat to adults. The zebra can be a formidable adversary, since they have a strong bite and a kick powerful enough to kill land predators. They often try to outrun larger predators such as lions and spotted hyenas, whereas they often stand their ground with the smaller predators.

Interactions with other grazers[edit]

Plains zebra herds will mix and migrate together along with other species such as wildebeests. Wildebeests and zebras generally coexist peacefully and will alert each other to predators. However, aggressive interactions occasionally occur.[20][21]

Behavior[edit]

Social structure[edit]

A zebra harem in Etosha National Park

The plains zebra is highly social and usually forms small family groups called harems, which consist of a single stallion, several mares, and their recent offspring. The adult membership of a harem is highly stable, typically remaining together for months to years. Groups of all male "bachelors" also exist. These are stable groups of 2-15 males with an age-based hierarchy lead by a young male.[4] These males stay in their groups until they are ready to start a harem. The bachelors prepare for their adult roles with play fights and greeting/challenge rituals, which take up most of their activities.[4] Multiple harems and bachelor groups come together to form herds. Plains zebras are unusual among harem-holding species in forming these groups.[22] In addition, pairs of harems may create temporarily stable subgroups within a herd, allowing individuals to interact with those outside their group.[22] Among harem-holding species, this has only been observed in primates like the gelada and the hamadryas baboon.[22]

Stallions form and expand their harems by abducting young mares from their natal harems.[4][23] When a mare reaches sexual maturity, she will exhibit the estrous posture, which attracts nearby stallions,[23] both bachelors and harem leaders. Her family stallion (likely her father) will chase off or fight stallions attempting to abduct her. Even after a young mare is isolated from her natal harem, the fight over her continues until her estrous cycle is over, and it starts again with the next estrous cycle.[24] It is rare that the mare's original abductor keeps her for long.[24] When the mare finally ovulates, the male that impregnates her keeps her for good. Thus, the mare becomes a permanent member of a new harem.[24][25] The estrous posture of a female becomes less noticeable to outside males as she gets older, hence competition for older females is virtually non-existent.[15]

Two zebras fighting

Mares exist in a hierarchy, with the alpha female being the first to mate with the stallion and being the one to lead the group. When new mares are added to the group, they are met with hostility by the other mares. Thus, the stallion must shield the new mares until the aggression subsides.[4][25] The most recently added females rank lowest. Females that become unfit or weak may drop in their rank, though. The female memberships of a harem stay intact even if a new stallion takes over. Females in a harem tend to be hostile to outside females.[15] Zebras strengthen their social bonds with grooming. Members of a harem nip and scrape along the neck, shoulders, and back with their teeth and lips. Mothers and foals groom the most often, followed by siblings. Grooming shows social status and eases aggressive behavior.[4]

A stallion will defend his group from other males. When challenged, the stallion would issue a warning to the invader by rubbing nose or shoulder with him. If the warning is not heeded, a fight breaks out. Zebra fights often become very violent, with the animals biting at each other's necks, heads or legs, wrestling to the ground, and occasional kicking. Sometimes a stallion will lie still on the ground as if surrendering, but once the other male lets up, will strike and continue the fight.[4] Most fighting occurs over young mares in estrus, and as long as a harem stallion is healthy, he will usually not be challenged. Only unhealthy stallions have their harems taken over, and even then the new stallion gradually takes over pushing the old one out without a fight.[4]

Communication[edit]

At least six different calls have been documented for the plains zebra. One of which is its distinctive high-pitched contact call heard as "a-ha, a-ha, a-ha" or "kwa-ha, kaw-ha, ha, ha".[15] When a predator is sighted, a zebra will make a two-syllable alarm call. A loud snort is made when moving in cover of potential danger. When in contentment, a zebra will make a more drawn-out snort. Males will make a short high-pitched squeal when hurt and foals will emit a drawn out wail when in distress.[15] There are two main facial expressions made by zebras. One is for greeting and involves the ears sticking up and directed forward; the other is threatening and involves the ears down.[15]

Reproduction[edit]

Mother zebra nursing her foal

The stallion mates with all his mares. Mares may give birth to one foal every twelve months. The birthing peak is during the rainy season. She nurses the foal for up to a year. The stallion is generally intolerant of foals that are not his. It is possible that zebras practice infanticide and feticide; such incidences have been observed in both captive individuals[26] and in nature. In the film "Great Zebra Exodus," a mare was trying to protect her foal from a new stallion as its father was a fallen stallion.[27] Like horses, zebras are able to stand, walk, run from danger, and suckle shortly after they are born. At the moment of birth, a mother zebra keeps any other zebra away from her foal, including the stallion, the other mares, and even the previous offspring. Later, though, they all bond. Within the group, a foal has the same rank as its mother.[15] Plains zebra foals are protected by their mother as well as the head stallion and the other mares in their group. Even with parental protection, up to 50% of zebra foals are taken by predation, disease, and starvation each year.

Young male zebras eventually leave their family groups. This is not because of sexual maturity or being kicked out by their fathers, but because their relationship with their mothers have faded after the birth of a sibling.[8][23] The young stallion then seeks out other young stallions for company.[23] Young females may stay in the harem until they are abducted by another stallion.[8]

Anti-predator behavior[edit]

For protection from land predators, the plains zebra retreats into open areas with good visibility at night. When the groups forage or sleep, one zebra will keep watch, and if a predator is spotted, it will bark or snort loudly.[8] When being hunted by hyenas or wild dogs, a zebra harem stays close together and cooperates to protect threatened members,[4] particularly the young. The harem stallion will go on the offensive and attack the dogs or hyenas.[4] Though hyenas may harass the stallion, they usually only concentrate on the herd, and attempt to dodge the stallion's assaults. Unlike stallions, mares typically only react aggressively to hyenas or dogs when their foals are threatened. Unlike wildebeest, zebras rarely take to water when escaping hyenas.[28] With lions, a zebra's best defense is to outpace them, as lions do not have as much endurance as hyenas or wild dogs. Cheetahs and leopards are mostly threats to foals as an adult zebra is fully capable of driving them away.

Human interactions[edit]

Conservation[edit]

Overall, the plains zebra population remains stable, and the species faces no major threat that would cause range-wide decline.[1] The zebra can be found in numerous protected areas across its range, including 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. There are some stable populations in unprotected areas.[1]

Zebras on the Botswana coat of arms

Some local populations, though, have faced great declines and even extinctions. One subspecies, the quagga, is now extinct. In Tanzania, the zebra population has decreased by 20% from the late 1990s to the mid-2000s.[1] Zebras are threatened by hunting for their hide and meat, and habitat change from farming. They also compete with livestock for food,[29][30] and are sometimes culled. Poaching is largely a threat to northern populations, while southern populations are threatened mostly by habitat loss. Recent civil wars in Rwanda, Somalia, South Sudan, Ethiopia, and Uganda have caused dramatic declines in all wildlife populations, including those of plains zebra. It is now extinct in Burundi. Civil war in Angola during much of the past 25 years has devastated its wildlife populations, including its once-abundant plains zebra, and destroyed the national parks administration and infrastructure.

Nevertheless, plains zebras are protected in most of their range. They are an important economic source in tourism.

In culture[edit]

The zebra is revered in some African cultures as a symbol of beauty. In the dances of the Karamojong tribe of Uganda, women would paint themselves in zebra stripes and act like them.[8] The Dube tribe of South Africa features a zebra on its totem. Zebras also appear on the coat of arms of Botswana.

References[edit]

  1. ^ a b c d e f Hack, M. A. and Lorenzen, E. (2008). Equus quagga. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 10 April 2009. Database entry includes a brief justification of why this species is of least concern.
  2. ^ Grubb, P. (2005). "Order Perissodactyla". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. p. 630. ISBN 978-0-8018-8221-0. OCLC 62265494. 
  3. ^ Orlando, Ludovic; et al. (2009). "Revising the recent evolutionary history of equids using ancient DNA". PNAS 106: 21754–21759. doi:10.1073/pnas.0903672106. PMC 2799835. PMID 20007379. 
  4. ^ a b c d e f g h i j k l m Estes 1991
  5. ^ J. E. Cordingley, S. R. Sundaresan, I. R. Fischhoff, B. Shapiro, J. Ruskey, D. I. Rubenstein (2009). Is the endangered Grevy's zebra threatened by hybridization?. Animal Conservation. 12: 505–513.
  6. ^ [1] (2011).
  7. ^ [2] (2011).
  8. ^ a b c d e f g h i Kingdon 1988
  9. ^ a b c d e Moehlman 2002
  10. ^ a b c d Prothero 2003
  11. ^ "Mutations". Messybeast.com. Retrieved 2012-07-03. 
  12. ^ "Mount Kenya Bush Drums December 2006". Animalorphanagekenya.org. Retrieved 2012-07-03. 
  13. ^ a b c d e Apps 2006
  14. ^ How, Martin J.; Zanker, Johannes M. (2014). "Motion camouflage induced by zebra stripes". Zoology: TBA. doi:10.1016/j.zool.2013.10.004. 
  15. ^ a b c d e f g Grub 1981
  16. ^ Egri, Ádám; Blahó, Miklós; Kriska, György; Farkas, Róbert; Gyurkovszky, Mónika; Åkesson, Susanne; Horváth, Gábor (2012). "Polarotactic tabanids find striped patterns with brightness and/or polarization modulation least attractive: an advantage of zebra stripes". J Exp Biol 215: 736–745. doi:10.1242/jeb.065540. 
  17. ^ Groves C. P. (1974) Horses, Asses and Zebras in the Wild. Hollywood, California, US: Ralph Curtis Books
  18. ^ Lamprey, H. F. (1963). Ecological separation of large mammal species in the Tangayika Game Reserve, Tangayika. E. Afr. Wildl. J. 63–93
  19. ^ Moehlman 2003
  20. ^ "Zebra Attack Blue Wildebeest Foal". Wilderness-safaris.com. 2007-04-25. Retrieved 2012-07-03. 
  21. ^ National Geographic Zebra: Patterns in the Grass (1991)
  22. ^ a b c Rubenstein and Hack
  23. ^ a b c d Moss 1982
  24. ^ a b c Klingel 1969
  25. ^ a b Adlen et al. 1995
  26. ^ "Further evidence for male infanticide and feticide in captive plains zebras" (PDF). Retrieved 2012-07-03. 
  27. ^ min 43 http://video.pbs.org/video/2365009194/
  28. ^ Kruuk, Hans (1972). The Spotted Hyena: A study of predation and social behaviour. p. 335. ISBN 0-563-20844-9. 
  29. ^ Young, T. P.; T. M. Palmer & M. E. Gadd (2005). "Competition and compensation among cattle, zebras, and elephants in a semi-arid savanna in Laikipia, Kenya". Biological Conservation 121: 351–359. doi:10.1016/j.biocon.2004.08.007. 
  30. ^ Odadi, W. O.; T. P. Young & J. B. Okeyo-Owour (2009). "The effects of wild herbivores on cattle intake and movement rates in Laikipia rangeland, Kenya.". Applied Animal Behaviour Science 116: 120–125. doi:10.1016/j.applanim.2008.08.010. 

Bibliography[edit]

  • Alden, P. C., Estes, R. D., Schlitter, D., McBride, B. (1995). National Audubon Society Field Guide to African Wildlife. New York, Chanticleer Press, Inc. pg. 151
  • Apps, P., du Toit, R. (2006). Creatures of Habit: Understanding African Animal Behaviour. Struik. pp. 74–75.
  • Estes, R. (1991). The Behavior Guide to African Mammals, Including Hoofed Mammals, Carnivores, Primates. Los Angeles, University of California Press. pp. 242–246
  • Groves, C. P.; Bell, H. B. (2004). "New investigations on the taxonomy of the zebras genus Equus, subgenus Hippotigris". Mammalian Biology 69: 182–196. doi:10.1078/1616-5047-00133. 
  • Grubb, P. (1981). "Equus burchellii". Mammalian Species 157: 1–9. doi:10.2307/3503962. 
  • Hack, M. A., East, R. & Rubenstein, D. I. (2008). "'Equus quagga ssp. quagga'". IUCN Red List of Threatened Species. Version 2011.1. International Union for Conservation of Nature. Retrieved 17 August 2011.  (extinct subspecies of the plains zebra.)
  • Higuchi, et al. (1987). "Mitochondrial DNA of the Extinct Quagga: Relatedness and Extent of Postmortem Change". Journal of Molecular Evolution 25: 283–287. doi:10.1007/BF02603111. PMID 2822938. 
  • Kingdon, J. (1988). East African Mammals: An Atlas of Evolution in Africa, Volume 3, Part B: Large Mammals. Chicago, University of Chicago Press. pp. 165–179
  • Klingel, H. (1969). "Reproduction in the plains zebra Equus burchelli boehmi: behaviour and ecological factors". J. Reprod. Fertil., Suppl 6: 339–345. 
  • Moelman, P. D. (2002). Equids. Zebras, Assess and Horses. Status Survey and Conservation Action Plan. IUCN/SSC Equid Specialist Group. IUCN, Gland, Switzerland. Chapter 4. Status and Action Plan for the Plains Zebra (Equus burchelli). Mace A. Hack, Rod East and Dan J Rubenstein. pp. 43–57.
  • Moehlman, P. D. (2003). Grizmek's Animal Life Encyclopedia. Mammals IV. Detroit, The Gale Group, Inc. 15.
  • Moss, C., Ed. (1982). Portraits in the Wild, Animal Behavior in East Africa. Chicago, University of Chicago Press.
  • Prothero, D. R.; Schoch, R. M. (2003). Horns, Tusks, and Flippers: The Evolution of Hoofed Mammals. Johns Hopkins University Press.
  • Rubenstein, D. I. & M. Hack (2004) Natural and sexual selection and the evolution of multi-level societies: insights from zebras with comparisons to primates. pp. 266–279. In: Sexual Selection in Primates: New and Comparative Perspectives. P. Kappeler and C. P. van Schaik (eds.). Cambridge University Press.
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