The quagga ( or ) (Equus quagga quagga) is an extinct subspecies of the plains zebra which was endemic to South Africa until it was hunted to extinction in the late 19th century. It was long thought to be a distinct species, but mtDNA studies have supported it being a subspecies of plains zebra. A more recent study suggested that it was the southernmost cline or ecotype of the species.
The quagga is believed to have been around long and tall at the shoulders. 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 appeared 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. Quaggas were said to be wild and lively, yet were also considered more docile than the related 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.
After the European settlement of South Africa began, the quagga was extensively hunted, as it competed with domesticated animals for forage. Some were taken to zoos in Europe, but breeding programmes were unsuccessful. The last wild population lived in the Orange Free State; the quagga was extinct in the wild by 1878. The last captive specimen died in Amsterdam on 12 August 1883. 23 skins and seven skeletons exist today, and only two quaggas were ever photographed alive. In 1984, the quagga was the first extinct animal whose DNA was analysed. The Quagga Project has attempted to breed Burchell's zebras with similar striping patterns to the quagga.
Taxonomy
It has been historically suggested that the name quagga is derived from the Khoikhoi word for zebra (cf. Tshwa 'zebra'), thereby being an onomatopoeic word, resembling the quagga's call, variously transcribed as "kwa-ha-ha", "kwahaah", Traditionally, the quagga and the other plains and mountain zebras were placed in the subgenus Hippotigris. Most experts now suggest that the two subspecies represent two ends of a cline. 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. One craniometric study from 1980 seemed to confirm its affiliation with the horse (Equus ferus caballus), but early morphological studies have been noted as being erroneous. Studying skeletons from stuffed specimens can be problematic, as early taxidermists sometimes used donkey and horse skulls inside their mounts when the originals were unavailable.
The quagga was the first extinct animal to have its DNA analysed, 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, A 1987 study suggested that the mtDNA of the quagga diverged at a range of roughly 2 percent per million years, similar to other mammal species, and again confirmed the close relation to the plains zebra.
Later morphological studies came to different 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. In spite of these findings, many authors subsequently kept the plains zebra and the quagga as separate species.
thumb|right|1889 illustration of a quagga (lower left) alongside other [[equines]]
The simplified cladogram below is based on the 2005 analysis (some taxa shared haplotypes and could therefore not be differentiated):
Description
The quagga is believed to have been long and tall at the shoulders. Its coat pattern was unique among equids: zebra-like in the front but more like a horse in the rear.
The quagga appears to have had a high degree of polymorphism, with some 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. Like other plains zebras, the quagga did not have a dewlap on its neck as the mountain zebra does. Quaggas have been reported gathering into herds of 30–50, and sometimes travelled in a linear fashion.</blockquote>
thumb|left|1777 illustration of a live quagga [[Colt (horse)|colt and a bagged adult Burchell's zebra male, by Robert Jacob Gordon.]]
The practical function of striping in zebras has been debated and 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 evidence 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, A 2014 study strongly supported the biting-fly hypothesis, and the quagga appears to have lived in areas with lesser amounts of fly activity than other zebras.
A 2020 study suggested that the sexual dimorphism in size, with quagga mares being larger than stallions, could be due to the cold and droughts that affects the Karoo plateau, conditions that were even more severe in prehistoric times, such as during ice ages (other plains zebras live in warmer areas). Isolation, cold, and aridity could thereby have affected quagga evolution, including coat colour and size dimorphism. Since plains zebra mares are pregnant or lactate for much of their lives, larger size could have been a selective advantage for quagga mares, as they would therefore have more food reserves when food was scarce. Dimorphism and coat colour could also have evolved through genetic drift due to isolation, but these influences are not mutually exclusive, and could have worked together. 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 exploited. The quagga was probably vulnerable to extinction due to its restricted range. Local farmers used them as guards for their livestock, as they were likely to attack intruders. On the other hand, captive quaggas in European zoos were said to be tamer and more docile than Burchell's zebra.
The quagga was long regarded a suitable candidate for domestication, as it counted as the most docile of the zebras. The Dutch colonists in South Africa had considered this possibility, because their imported work horses did not perform very well in the extreme climate and regularly fell prey to the feared African horse sickness. In 1843, the English naturalist Charles Hamilton Smith wrote that the quagga was 'unquestionably best calculated for domestication, both as regards strength and docility'. Some mentions have been given of tame or domesticated quaggas in South Africa. In Europe, two stallions were used to drive a phaeton by the sheriff of London in the early 19th century.
In an attempt at domesticating the quagga, the British lord George Douglas, 16th Earl of Morton obtained a single male which he bred with a female horse of partial Arabian ancestry. This produced a female hybrid with 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. It is unknown what happened to the hybrid mare itself. This led to new ideas on telegony, referred to as pangenesis by the British naturalist Charles Darwin. At the close of the 19th century, the Scottish zoologist James Cossar Ewart argued against these ideas and proved, with several cross-breeding experiments, that zebra stripes could appear as an atavistic trait at any time.
There are 23 known stuffed and mounted quagga specimens throughout the world, including a juvenile, two foals, and a foetus. In addition, a mounted head and neck, a foot, seven complete skeletons, and samples of various tissues remain. A 24th mounted specimen was destroyed in Königsberg, Germany, during World War II, and various skeletons and bones have also been lost. A mare at the Zoological Society of London's Zoo was long thought to be the only quagga to have been photographed alive. Five photographs of this specimen are known, taken between 1863 and 1870. In 2022, a pair of stereophotographs depicting a quagga among other animals was rediscovered. They were taken on 8 April 1864 at the farm of Andrew Hudson Bain, 'Quaggafontein' in the Orange Free State southwest of Bloemfontein by the German anthropologist Gustav Theodor Fritsch. He used them as basis for a woodcut he published in his 1868 book, and while doubt was since raised of whether it showed a quagga as labeled or a Burchell's zebra, the zoologists Peter Heywood and Keith H. Dietrich argued for the former in 2021 based on its striping and Fritsch's expertise.
Extinction
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. Its death was not recognised as signifying the extinction of its kind at the time, and the zoo requested another specimen; hunters believed it could still be found "closer to the interior" in the Cape Colony. Since locals used the term quagga to refer to all zebras, this may have led to the confusion. The specimen itself was mounted and is kept in the collection of Naturalis Biodiversity Center in Leiden. It has been on display for special occasions. In 1889, the naturalist Henry Bryden wrote: "That an animal so beautiful, so capable of domestication and use, and to be found not long since in so great abundance, should have been allowed to be swept from the face of the earth, is surely a disgrace to our latter-day civilization."
Breeding back project
After the very close relationship between the quagga and extant plains zebras was discovered, Rau started the Quagga Project in 1987 in South Africa to create a quagga-like zebra population by selectively breeding for a reduced stripe pattern from plains zebra stock, with the eventual aim of introducing them to the quagga's former range. To differentiate between the quagga and the zebras of the project, they refer to it as "Rau quaggas".
Introduction of these quagga-like zebras could be part of a comprehensive restoration programme, 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 considered looking 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 has not yet been developed.
See also
- Holocene extinction
- Lists of extinct animals