The tarpan or Eurasian wild horse, Equus caballus ferus or E. ferus, is an extinct wild horse related to the common domestic horse (E. caballus caballus) that roamed from southern France and Spain to central Russia, in steppe and forest environments. They stood approximately 140-145 centimetres (55-57 inches) tall at the shoulders, had a partly falling mane, a mouse-grey (grullo) coat color, dark legs and primitive markings, including a dorsal stripe and shoulder stripes. Smith (1866) described tarpans as mule-like, and making stronger sounds than domestic horses (Mass 2000-2013; Wikipedia 2014).
The name “tarpan” is Turkic for “wild horse,” and is distinguished from the feral horse (called Takja or Muzin). In modern use, the term has been loosely used to refer to the pre-domesticated ancestor of the modern horse, Equus ferus; to the pre-domestic subspecies believed to have lived into the historic era, Equus caballus ferus; and nonspecifically to all European primitive or "wild" horses in general (Wikipedia 2014). Other common synonyms for tarpans are Equus ferus ferus and E. c. gmelini.
Beginning in the 1930s, several attempts were made to genetically reconstruct horses that looked like tarpans through selective breeding, called “breeding back” by advocates. The breeds that resulted include the Heck horse, the Hegardt or Stroebel's horse, and a derivation of the Konik breed, all of which have a primitive appearance, particularly in having the grullo coat color. Some of these horses are now commercially promoted as "tarpans," although researchers discourage this use of the word, which they believe should only applied to the ancient E. caballus ferus (Castelli 2012).
Tarpans became extinct starting in Southern Europe, as a result of human hunting and a range decreasing in size with the increasing civilization of the Eurasian continent. They were persecuted because they caused damage to hay storages, often took domestic mares from pastures and because interbreeding with wild horses was an economic loss for farmers since the foals of such matings were intractable. Tarpans survived the longest in the southern parts of the Russian steppe. By 1880, when most “Tarpans” may have become hybrids, wild horses were very rare. In 1879 the last scientifically confirmed individual was killed. After that, only dubious sightings were documented. As the tarpan horse died out in the wild between 1875 and 1890, the last considered-wild mare was accidentally killed during an attempt at capture. The last captive individual believed to be a tarpan died in 1909 in a Russian zoo (Wikipedia 2014).
- Bennett, D. & Hoffmann, R.S. 1999. Equus caballus. Mammalian Species. American Society of Zoologists. 628:1-14. Retrieved February 24 2014 from http://www.equinestudies.org/mammalian_species_2008/mammalian_species_equus_caballus_pdf1.pdf
- Castelli, A. 2012). Don't Call Me Tarpan. Scribed. Retrieved 24 Feb 2014 from http://www.scribd.com/doc/131666793/Don-t-Call-Me-Tarpan.
- Mass, P. 2000-2013. Equus ferus ferus. The Sixth Extinction Website. Retrieved February 24 2014 from http://www.petermaas.nl/extinct/speciesinfo/tarpan.htm.
- Smith, C.H. 1866. The Natural history of Horses, with Memoir of Gesner. In: The Naturalists Library, Sir W. Jardine, Ed. Vol. xx. Mammalia, horses. Henry G. Bohn, York Street, Covent Garden, London. Retrieved February 26, 2014 from http://books.google.com/books/about/The_Natural_History_of_Horses_with_Memoi.html?id=xykBAAAAQAAJ
- Wikipedia, The Free Encyclopedia, 29 January 2014. Tarpan. Retrieved February 24 2014 from http://en.wikipedia.org/w/index.php?title=Tarpan&oldid=593023990
Since the 1990s, reintroduction efforts have started in Mongolia, China, Kazakhstan and Ukraine; Mongolia is the only country where truly wild reintroduced populations exist within its historic range. Reintroductions in Mongolia began in Takhin Tal Nature Reserve in the Dzungarian Gobi Desert (9,000 km²) and Hustai National Park in Mongol Daguur Steppe (570 km²) in 1994 (King and Gurnell 2005). A third reintroduction site, Khomiin Tal, (2,500 km²), in the Great Lakes Depression, was established in 2004, as a buffer zone to the Khar Us Nuur National Park in Valley of the Lakes (C. Feh pers. comm.).
All living wild horses belong to the subspecies Equus ferus przewalskii. The first visual account of Przewalski’s-type wild horses date from more than 20,000 years ago. Rock engravings, paintings, and decorated tools dating from the late Gravetian to the late Magdalenian (20,000–9,000 BC), were discovered in caves in Italy, southern France, and northern Spain; 610 of these were horse figures (Leroi-Gourhan 1971). Many cave drawings in France show horses that look like Przewalski’s Horse (Mohr 1971). In prehistoric times, the species probably roamed widely over the steppes of central Asia, China, and Europe (Ryder 1990). The first written accounts originate from Tibet, recorded by the monk Bodowa, who lived around 900 AD. In the “Secret History of the Mongols”, there is also a reference to wild horses that crossed the path of Chinggis Khaan during his campaign against Tangut in 1226, causing his horse to rear and throw him to the ground (Bokonyi 1974). That the wild horse was a prestigious gift, denoting its rarity or that it was difficult to catch, is shown by the presentation of a Przewalski’s horse to the emperor of Manchuria by Chechen-Khansoloj-Chalkaskyden, an important Mongolian, circa 1630 (Zevegmid and Dawaa 1973). In a Manchurian dictionary of 1771, Przewalski’s Horse is mentioned as “a wild horse from the steppe” (Dovchin 1961).
Przewalski’s Horse was not described in Linnaeus’s “Systema Naturae” (1758) and remained largely unknown in the West until first mentioned by John Bell, a Scottish doctor who travelled in the service of Tsar Peter the Great in 1719–1722 (Mohr 1971). His account of the expedition, “A Journey from St Petersburg to Peking”, was published in 1763. Bell and subsequent observers all located horses known at that time within the area of 85–97°E and 43–50°N (Chinese-Mongolian border). Wild horses were reported again from what is now China by Colonel Nikolai Mikailovich Przewalski, an eminent explorer, at the end of the nineteenth century. He made several expeditions by order of Tsar Alexander the Second of Russia to central Asia, aiming to reach Tibet. While returning from his second expedition in central Asia, he was presented with the skull and hide of a horse shot about 80 km north of Gutschen on the Chinese-Russian border. The remains were examined at the Zoological Museum of the Academy of Science in St Petersburg by I.S. Poliakov, who concluded that they were a wild horse, which he gave the official name Equus przewalskii (Poliakov 1881). Further reports came from the brothers Grigory and Michael Grum-Grzhimailo, who travelled through western China from 1889-1890. In 1889, they discovered a group in the Gashun area and shot four horses: three stallions, and a mare. The four hides and the skulls of the three stallions, together with an incomplete skeleton, were sent back to the Zoological Museum in St. Petersburg. They were able to observe the horses from a short distance and gave the following account: “Wild horses keep in bands of no more than ten, each herd having a dominant stallion. There are other males, too, but they are young and, judging by the hide of the two-year old colt that we killed, the dominant male treats them very cruelly. In fact, the hide showed traces of numerous bites” (Grum-Grzhimailo 1982). Current scientific review of the taxonomy of wild equids (Groves 1986) places Przewalski’s Horse as a subspecies of Equus ferus.
Habitat and Ecology
Przewalski’s Horse formerly inhabited steppe and semi-desert habitats, as most of this range became degraded or was occupied by livestock, the species became restricted to semi-desert habitats with limited water resources (Van Dierendonck and de Vries 1996). Lowland steppe vegetation was preferentially selected by horses at Hustai National Park and seasonal movements are affected by the availability of the most nutritious vegetation (King and Gurnell 2005).
Because the historic range is not precisely known, there has been much debate about the areas in which Przewalski’s Horses were last seen: was it merely a last refuge or was it representative of the typical/preferred habitat? The Mongolia Takhi Strategy and Plan Work Group (MTSPWG 1993) concluded that the historic range may have been wider but that the Dzungarian Gobi, where they were last seen, was not a marginal site to which the species retreated. Although grass and water are more available in other parts of Mongolia, these areas often have much harsher winters
IUCN Red List Assessment
Red List Category
Red List Criteria
- 2008Critically Endangered(IUCN 2008)
- 2008Critically Endangered
- 1996Extinct in the Wild
There are now approximately 306 free-ranging reintroduced and native-born Przewalski’s Horses in Mongolia (Zimmerman 2011). All Przewalski’s Horses alive today are descended from only 13 or 14 individuals, which were the nucleus of a captive breeding program (Bowling and Ryder 1987). Introgression of domestic horse blood happened not only in Halle (#229 dom.Mongol), but also in Askania Nova (#175 Domina; Bowling et al. 2003).
Between 1992 and 2004, 90 captive-born horses were transported to the Takhin Tal/Gobi B reintroduction site in Mongolia (ITG International Takhi Group, Zimmermann 2008). A further three males were translocated from Hustai National Park to Takhin Tal in 2007 (Zimmermann 2008). In 2008 there were approximately 111 free-ranging horses in this population (Zimmerman 2008, Kaczensky and Walzer 2007). In December of 2009 there were 137 individuals in the population, but due to an extremely harsh winter (dzud) the population suffered extreme mortality and by August 2010 only 49 individuals remained (Kaczensky et al. 2010, Zimmerman 2011). From 1992 to 2000, 84 horses were brought to Hustai National Park by the Foundation for the Preservation and Protection of the Przewalski Horse and Mongolian Association for Conservation of Nature and the Environment (MACNE) from reserves in Europe (King and Gurnell 2005). As of the end of 2010 this population was approximately 233 individuals (Zimmerman 2011). A third reintroduction site was started in 2004 at Seriin Nuruu in the Khomiin Tal buffer zone of the Khar Us Nuur National Park in western Mongolia (Association pour le cheval de Przewalski: TAKH). Twenty-two individuals consisting of four pre-established families and one male bachelor group were brought from Le Villaret, France between 2004 and 2005 (C. Feh pers. comm., Zimmermann 2008). In 2010, this population had 24 individuals (Zimmermann 2011).
For the reintroduced population in Mongolia, mature individuals are those that are born in the wild and five years of age. However, individuals born in captivity do not count as mature until they have reproduced in the wild and that offspring is at least five years old. As of 2006 there were 55 mature individuals in the wild (52 (M.F., 26.26) in Hustai, 3 (1.2) in Takhin Tal). In 2007 Hustai had 68 (33.35) mature individuals and Takhin Tal had 11 (3.8) for a total of 79. The reintroduced populations continued to grow and in 2008, Hustai had 90 (39.51) and Takin Tal had 14 (7.7) mature individuals for a total of 104. In 2009, Hustai had a population of 118 mature individuals (52.66) and Takin Tal had 33 (15.18) for a total of 151. The winter of 2009/2010 was very severe and there was high mortality of Przewalski’s Horses, particularly in Takin Tal. In 2010, Hustai’s mature population was 117 (53.64) and Takin Tal’s number of mature individuals was reduced to 17 (8.9). However, the total population of mature individuals was 134. Hence for a period of five years, the mature population of Przewalski’s Horses in Mongolia has been more than 50 individuals. Although this means that the Przewalski’s Horse qualifies as Endangered it should be borne in mind that most of these individuals are from one reintroduction site and climatic perturbations like the extremely harsh winter in 2009/2010 can have very negative effects on small populations.
The history of population estimates and trends in Przewalski’s Horse has been described by Wakefield et al. (2002). Since the ‘rediscovery’ of the Przewalski’s Horse for western science, western zoos and wild animal parks became interested in this species for their collections. Several long expeditions were mounted to catch animals. Some expeditions came back empty-handed and some had only seen a glimpse of wild Przewalski’s Horses. It proved difficult to catch adult horses, because they were too shy and fast. Capture of foals, with possible killing of the adult harem members, was considered the only option (Bouman and Bouman 1994). Four expeditions that managed to catch live foals took place between 1897 and 1902. Fifty-three of these foals reached the west alive. Between the 1930s and the 1940s only a few Przewalski’s Horses were caught and most died. At least one mare was crossbred with domestic horses by the Mongolian War Ministry (Bouman and Bouman 1994).
Small groups of horses were reported through the 1940s and 1950s in an area between the Baitag-Bogdo ridge and the ridge of the Takhin-Shaar Nuruu (which, translated from Mongolian, means ‘the Yellow Mountain of the Wild Horse’), but numbers appeared to decline dramatically after World War II. The last confirmed sighting in the wild was made in 1969 by the Mongolian scientist N. Dovchin. He saw a stallion near a spring called Gun Tamga, north of the Takhin-Shaar Nuruu, in the Dzungarian Gobi (Paklina and Pozdnyakova 1989). Annual investigations by the Joint Mongolian-Soviet Expedition have since failed to find conclusive evidence for their survival in the wild (Ryder 1990). Chinese biologists conducted a survey in northeastern Xinjiang from 1980 to 1982 (covering the area of 88–90°E and 41°31'–47°10'N) without finding any horses (Gao and Gu 1989). The last native wild populations had disappeared.
The number of living animals in the International Studbook was 1,872 in early 2008. Of the 53 animals recorded in the Studbook as having been brought into zoological collections in the west, only 12 contributed any genes to the current living population. Of these, 11 were brought into captivity between 1899 and 1902 and the last of them died in 1939. The twelfth founder was captured as a foal in 1947. The thirteenth founder was born in 1906 in Halle (Germany) to a wild-caught stallion and a domestic Mongolian mare, and the fourteenth founder is a female born in Askania Nova (Ukraine) to a Przewalski’s Horse stallion and a domestic female of a Tarpan type. Nevertheless, the current population is genetically very close to the original wild horses (Bowling et al. 2003). In addition to animals held in captivity and those already re-introduced, there have been a number of animals released into very large enclosures (reserves). The four largest are in Le Villaret (18.13; Massif Central, France), Buchara (19.17.1; Uzbekistan), the Hortobágy-National Park (77.81; Hungary), and the Chernobyl exclusion zone (32.37; Ukraine) (information as of January 2010, W. Zimmermann pers. comm.).
For the reintroduced populations, hybridization with domestic horses is the primary threat, accompanied by competition for resources with domestic horses and possibly other livestock. Wherever Przewalski's Horses come into contact with domestic horses, there is a strong risk of hybridization and transmission of diseases. Recently, illegal mining in the protected areas is an additional threat to the viability of these areas. In Hustai National Park, it has been noted that overgrazing of the buffer-zone and continued pressure on the reserve are possible consequences of the enhanced economic activity in this area (Bouman 1998); however, the second phase of the project (1998-2003) paid much more attention to sustainable development of the buffer-zone. In the western section of the Gobi National Park (Gobi B), habitat degradation by nomads and military personnel and their livestock continues; there is no core zone here that is free from human influence all year round. Infectious diseases transmitted from domestic horses, notably Babesia equi, B. caballi and strangles (infection by Streptococcus equi), are a major threat to small reintroduced populations originating from zoos (Roberts et al. 2005, King and Gurnell 2005). Predation on foals by wolves may account for a significant number of mortalities and constitutes a threat to the population growth and continued survival of this taxon (Wit and Bouman 2006, Kaczensky et al. 2004, Kaczensky and Walzer 2007). As was observed during 2009/2010, severe winters can result in significant mortality.
There is concern over loss of genetic diversity after being reduced to a very small population and maintained in captivity for several generations. Sixty per cent of the unique genes of the studbook population have been lost (Ryder 1994). Loss of founder genes is irretrievable and further losses must be minimized through close genetic management. Furthermore, inbreeding depression could become a population-wide concern as the population inevitably becomes increasingly inbred (Ballou 1994). However, correct management of the population can slow these losses significantly, as has been achieved since the organization of the regional captive-breeding programs.
Przewalski's Horse is legally protected in Mongolia. It is protected as Very Rare under part 7.1 of the Law of the Mongolian Animal Kingdom (2000). Hunting has been prohibited since 1930, and the species is listed as Very Rare under the 1995 Mongolian Hunting Law (MNE 1996). It is listed as Critically Endangered in both the 1987 and 1997 Mongolian Red Books (Shagdarsuren et al. 1987, MNE 1997), and in the Regional Red List for Mongolia (Clark et al. 2006). The taxon's entire reintroduced range in Mongolia is within protected areas. It is listed on CITES Appendix I (as Equus przewalskii).
The following conservation measures are in place:
- An International Studbook was produced in 1959, followed in the 1970s by establishment of the North American Breeders Group, which developed into the Species Survival Plan for the Przewalski’s horse. The European Endangered Species Program for this species was accepted in 1986. Many countries now cooperate in these programs to minimize inbreeding and retain genetic diversity in their horse populations.
- There are three ongoing reintroduction sites in Mongolia.
- The Status and Action Plan for the Przewalski's Horse (Equus ferus przewalskii) was produced in 2002 (see Wakefield et al. 2002), and provides a more detailed account of the history and ongoing conservation efforts surrounding the species.
- All three reintroduction sites are fully monitoring their populations and are integrating community livelihood support into their projects.
- There have been several workshops of stakeholders involved in the reintroduction of Przewalski's Horse to Mongolia (Boyd 2009). At the ‘Endangered Wild Equid Workshop’ held in Ulaanbataar in 2010 the following threats were identified: loss of population due to stochastic events (i.e., severe winter); limited habitat and resources (pasture and water); domestic horses (hybridization, disease, social stress); lack of information, appreciation / awareness, lack of knowledge; and exploitation of resources (i.e., mining). Specific actions needed for each threat category were identified and described.
Conservation measures required:
- The health of wild and domestic horses should be monitored for disease (Roberts et al. 2005). Standardized techniques should be used to monitor health, fecundity, mortality, habitat utilization and social organization of all populations (Wakefield et al. 2002), and contact between Przewalski's Horses and domestic horses should be kept to a minimum.
- A single population management approach should be developed.
- Mongolia currently has the only wild population and an action plan is needed for the country.
- The genealogy of all horses in Mongolia should be established based on individual micro-satellite data to monitor inbreeding levels, identify hybrids and plan for necessary movements of horses between reintroduction centres to maximize genetic diversity.
- An authoritative government protocol for hybrids should be developed, to be established before hybridization occurs, and to be made available in each re-introduction centre and to local people (King and Gurnell 2005).
- Further communication and cooperation between all re-introduction centres would be beneficial.
- Further training and post-graduate education of staff and biologists involved with this conservation work.
This species is one of a number which have been included in various “Pleistocene rewilding” plans. Pleistocene rewilding is the proposed practice of restoring ecosystems to their state in the Pleistocene, roughly 10,000 years ago. This contrasts the standard conservation benchmark, particularly in North America, of restoring ecosystems to their pre-Columbian or pre-industrial state. In both Eurasia and North America, the Pleistocene was characterized by much greater diversity and numbers of large herbivores and predators, including proboscidians, equids, camelids, and felidae (Donlan et al 2006; Zimov 2005). The process of restoration would involve the reintroduction of extant species in their historic range, as well as the introduction of ‘proxy organisms’ to replace the ecological functionality of extinct organisms (Donlan et al 2006).
There are three central theoretical goals to Pleistocene rewilding. In Siberia, a team led by Sergey Zimov is investigating the role of large herbivores as ecosystem engineers. It is thought that herbivory pressure could play a central role in maintaining a grass-dominated plant community, as opposed to either tree- or moss-dominated. Grasslands are known to be more stable carbon sinks than either mossy or forested tundra, due to the rapidity of their biogeochemical cycling (Zimov 2005). In principle, then, reintroducing Pleistocene fauna could have positive climate change mitigation effects. Proposals in North America have focused instead on the preservation of ecological dynamics. Proponents of Pleistocene rewilding argue that due to the strong ecological interactions of megafauna, it is likely that their extinction at the end of the Pleistocene would have caused cascading ecological disruptions lasting until the present time (Donlan et al 2006). Additionally, introduction programs could provide a new lease on life for extant, endangered megafauna species, such as cheetahs and Asian elephants (Rubenstein 2006).
Pleistocene rewilding, while headline-grabbing, is by no means the standard of modern conservation biology. There are a number of objections to the proposals of Pleistocene rewilders, summarized by Rubenstein et al (2006). The introduction of species which have been locally extinct for thousands of years, and more particularly the introduction of modern relatives of extinct species, carries many risks: the potential for invasive species, catastrophic disruption of existing ecosystems, inadvertent introduction of disease organisms, and unpredictable behavior of introduced species. Additionally, while paleoecology is a growing field, there is still a fair amount of uncertainty about the actual ecosystem functions of the Pleistocene.
Species which Zimov and his colleagues in Siberia are experimenting with bison, musk oxen, Przewalski’s horse, and Siberian tigers (Zimov 2005). Small-scale introductions have already begun in Yakutia. Donlan et al propose introducing Przewalski’s horse, Bolson tortoises, Bactrian camels, cheetahs, lions, and elephants into the Western United States (Donlan et al 2005). While some individuals of these species are present on privately owned land, there are no free-living populations in North America at this time.
- Donlan CJ, Berger J, Bock CE, Bock JH, Burney DA, Estes JA, Foreman D, Martin PS, Roemer GW, Smith FA, Soule ME, Greene HW. 2005. Pleistocene Rewilding: An Optimistic Agenda for Twenty-First Century Conservation. The American Naturalist 168:660-681.
- Donlan, CJ. 2005. Re-Wilding North America. Nature 436:913-914.
- Rubenstein DR, Rubenstein DI, Sherman PW, Gavin TA. 2006. Pleistocene Park: Does Rewilding North America Represent Sound Conservation for the 21st Century? Biological Conservation 132:232-238.
- Zimov, SA. 2005. Pleistocene Park: Return of the Mammoth’s Ecosystem. Science 308:796-798.
The Tarpan (Equus ferus ferus), also known as Eurasian wild horse, is an extinct subspecies of wild horse. The last individual believed to be of this subspecies died in captivity in Russia in 1909, although some sources claim that it was not a genuine wild horse due to its resemblance to domesticated horses.
Beginning in the 1930s, several attempts were made to develop horses that looked like Tarpans through selective breeding, called "breeding back" by advocates. The breeds that resulted included the Heck horse, the Hegardt or Stroebel's horse, and a derivation of the Konik breed, all of which have a primitive appearance, particularly in having the grullo coat color. Some of these horses are now commercially promoted as "Tarpans." However, those who study the history of the ancient wild horse assert that the word "Tarpan" only describes the true wild horse.
Name and etymology
The name "tarpan" or "tarpani" is from a Turkic language (Kyrgyz or Kazakh) name meaning "wild horse". The Tatars and Cossacks distinguished the wild horse from the feral horse; the latter was called Takja or Muzin.
In modern use, the term has been loosely used to refer to the predomesticated ancestor of the modern horse, Equus ferus, to the predomestic subspecies believed to have lived into the historic era, Equus ferus ferus, and to all European primitive or "wild" horses in general. The modern "bred-back" horse breeds are also promoted as "Tarpan" by their supporters, though researchers discourage this use of the word, which they believe should only apply to the ancient E. ferus ferus.
The Tarpan was first described by Johann Friedrich Gmelin in 1774; he had seen the animals in 1769 in the district of Bobrov, near Voronezh. In 1784 Pieter Boddaert named the species Equus ferus, referring to Gmelin's description. Unaware of Boddaert's name, Otto Antonius published the name Equus gmelini in 1912, again referring to Gmelin's description. Since Antonius' name refers to the same description as Boddaert's it is a junior objective synonym. It is now thought that the domesticated horse, named Equus caballus by Carl Linnaeus in 1758, is descended from the Tarpan; indeed, many taxonomists consider them to belong to the same species. By a strict application of the rules of the International Code of Zoological Nomenclature, the Tarpan ought to be named E. caballus, or if considered a subspecies, E. caballus ferus. However, biologists have generally ignored the letter of the rule and used E. ferus for the Tarpan to avoid confusion with its domesticated cousins.
It is debated if the small, free-roaming horses seen in the forests of Europe during 18th and 19th centuries and called "Tarpan" were indeed wild, never-domesticated horses, hybrids of the Przewalski's horse and local domestic animals, or simply feral horses. Most studies have been based on only two preserved specimens and research to date has not positively linked the Tarpan to Pleistocene or Holocene-era animals.
In 2003, the International Commission on Zoological Nomenclature "conserved the usage of 17 specific names based on wild species, which are pre-dated by or contemporary with those based on domestic forms", confirming E. ferus for the Tarpan. Taxonomists who consider the domestic horse a subspecies of the wild Tarpan should use Equus ferus caballus; the name Equus caballus remains available for the domestic horse where it is considered to be a separate species.
Traditionally, two Tarpan subtypes have been proposed, the Forest Tarpan and Steppe Tarpan, although there seem to be only minor differences in type. The general view is that there was only one subspecies, the Tarpan, Equus ferus ferus. The last individual, which died in captivity in 1909, was between 140 and 145 centimetres (55 and 57 in) tall at the shoulders, had a thick falling mane, a grullo coat colour, dark legs, and primitive markings, including a dorsal stripe and shoulder stripes.
A number of genotypes have been identified within European wild horses from the Pleistocene and Holocene; their color genes including those creating bay, black and leopard spotting are known to be present in the wild horse population in Europe and were depicted in Cave paintings of wild horses during the Pleistocene. The dun gene, a dilution gene seen in the Przewalski horse which also creates the grullo or "blue dun" coat, seen in the Konik has genetic markers identified in modern horses, but has not yet been studied in European wild horses. It is considered likely that at least some wild horses had a dun coat.
Some theorize that the Tarpan had a standing mane because all other extant wild equines display this feature, and falling manes are considered an indication of domestication. However, historical accounts do not unambiguously describe a standing mane in European wild horses, and it is likely that they had a short falling mane. This feature is advantageous in regions with much rainfall because it diverts rain and snow from the neck and face and prevents a loss of heat, as much as a bushy tail. Mummified Siberian wild horses display a hanging mane as well.
The appearance of European wild horses is reconstructed with genetic, osteologic and historic data. One genetic study suggests that bay was the predominant color in European wild horses. During the Mesolithic era, a gene coding a black coat color appeared on the Iberian peninsula. This color spread east but was less common than bay in the investigated sample and never reached Siberia. Bay in combination with dun results in the "bay dun" color seen in the Przewalski’s horse, black with dun creates the grullo coat. A loss of dun dilution may have been advantageous in more forested western European landscapes, as dark colors were a better camouflage in forests. Pangare or "mealy" coloration, a characteristic of other wild equines, might have been present in at least some Tarpans, as historic accounts report a light-colored belly. It is also likely that European wild horses had primitive markings, consisting of stripes on the shoulders, legs and spine.
Wild horses have been present in Europe since the Pleistocene and ranged from Southern France and Spain east to central Russia. There are cave drawings of primitive pre-domestication horses in France and Spain, as well as artifacts believed to show the species in southern Russia, where a horse of this type was domesticated around 3000 BC. Equus ferus had a continuous range from western Europe to Alaska; historic material suggests wild horses lived in most parts of Holocene Europe and the Eurasian steppe, except for parts of Scandinavia, Iceland and Ireland.
The "Forest Horse" or "Forest Tarpan" was a hypothesis of various 19th-century natural scientists, including Tadeusz Vetulani, who suggested that the continuous forestation of Europe after the last ice age created forest-adapted subtype of the wild horse, which he named Equus sylvestris. However, historic references do not describe any major difference between the populations, therefore most authors assume there was only one subspecies of western Eurasian wild horse, Equus ferus ferus. Nevertheless, a stocky type of horse living in forests and highlands was described during the 19th century in Spain, the Pyrenees, the Camargue, the Ardennes, Great Britain, and the southern Swedish upland. They had a robust head and strong body, and a long frizzy mane. The color was described as faint brown or yellowish brown with eel stripe and leg stripes, or wholly black legs. The flanks and shoulders were spotted, some of them tended to an ashy colour. They dwelled in rocky habitats and showed intelligent and fierce behaviour. In Dutch swamps, black wild horses were found with a large skull, small eyes and a bristly muzzle. The mane was full, with broad hooves and curly hair. However, it is possible that these were feral and not a wild horses.
Herodotus described lightly coloured wild horses in an area now part of the Ukraine in the 5th century BC. In the 12th century, Albertus Magnus states that mouse-coloured wild horses with a dark eel stripe lived in the German territory, and in Denmark, large herds were hunted. Wild horses still were common in the east of Prussia during the 15th and early 16th century. During the 16th century the wild horses disappeared from most of the mainland of western Europe and became less common in eastern Europe as well. Belsazar Hacquet saw wild horses in the Polish zoo in Zamość during the Seven Years’ War. According to him, those wild horses were of small body size, had a blackish brown colour, a large and thick head, short dark manes and tail hair and a “beard”. They were absolutely untameable and defended themselves harshly against predators. Kajetan Kozmian visited the population at Zamość as well and reported that they were small and strong, had robust limbs and a constantly dark mouse colour. Samuel Gottlieb Gmelin witnessed herds in Voronezh in 1768. Those wild horses were described as very fast and shy and would flee by any noise, small with small pinned ears, and a short frizzly mane. The tail was shorter than in domestic horses. They were described as mouse-colored with a light belly and legs becoming black, although gray and white horses were mentioned as well. The coat was long and dense. Peter Pallas witnessed possible wild Tarpans in the same year in southern Russia. He thought they were feral animals that escaped during the confusions of wars. These herds were important game of the Tatars and numbered between 5 and 20 animals. The horses he described had a small body, large and thick heads, short frizzly manes and short tail hair, as well as pinned ears. The colour was described as faint brownish, sometimes brown or black. He also reported of obvious domestic hybrids with lightly colored legs or grays.
The Natural History of Horses by 19th-century author Charles Hamilton Smith also described Tarpans. According to Smith, the herds of wild horses numbered from a few to hundred individuals. They often were mixed with domestic horses, and alongside pure herds there were herds of feral horses or hybrids. The color of pure Tarpans was described as constantly brown, cream-colored or mouse-colored. The short frizzy mane was reported to be black, as were the tail and legs. The ears either were of varying size, but set up high at the skull. The eyes were small. According to Smith, Tarpans made stronger sounds than domestic horses and the overall appearance of these wild horses was mule-like. A Tarpan herd survived in the Zoo of Zamość until 1806, when the reserve had to sell them because of economic problems. They were dispersed onto the local farms at the Biłgoraj region, tamed and bred to domestic horses. According to Kozmian, wild horses had been exterminated in the Polish wilderness shortly before, because they damaged hay collected for livestock.
The human-caused extinction of the Tarpan began in Southern Europe, possibly in antiquity. While humans had been hunting wild horses since the Palaeolithic, during historic times horsemeat was an important source of protein for many cultures. As large herbivores, the range of the Tarpan was continuously decreased by the increasing civilization of the Eurasian continent. Wild horses were further persecuted because they caused damage to hay storages and often took domestic mares from pastures. Furthermore, interbreeding with wild horses was an economic loss for farmers since the foals of such matings were intractable. Tarpans survived the longest in the southern parts of the Russian steppe. By 1880, when most "Tarpans" may have become hybrids, wild horses became very rare. In 1879 the last scientifically confirmed individual was killed. After that, only dubious sightings were documented. As the Tarpan horse died out in the wild between 1875 and 1890, the last considered-wild mare was accidentally killed during an attempt at capture. The last captive Tarpan died in 1909 in a Russian zoo.
An early 19th-century attempt was made by the Polish government to save the Tarpan type by establishing a preserve for animals descended from the Tarpan in a forested area in Bialowieza. In 1780, a wildlife park was established protecting a population of Tarpans until the beginning of the 19th century. When the preserve had to close down in 1806, the last remaining Tarpans were donated to local farmers and it is claimed that they survived through crossbreeding with domestic horses. The Konik is claimed to descend from these hybrid horses. However, there is no evidence that the Konik is genetically different in any significant degree from other domestic breeds, and thus claims that it is a descendant of the Tarpan cannot be substantiated.
Interbreeding with domestic horses
The oldest archaeological evidence for domesticated horses is from Kazakhstan and Ukraine between 6000 to 5500 years BP. The diverse mitochondrial DNA of the domestic horse coinciding with the very low diversity on the Y chromosome suggests that many mares but only very few stallions were used, and local use of wild mares or even secondary sites of domestication are likely. Therefore, the European Tarpan may have contributed to the domestic horse.
Some researchers consider the Tarpans of the last two centuries of their existence to be mixed wild and feral population or completely feral horses. Few consider the more recent animals historically called "Tarpans" to be genuine wild horses without domestic influence. Historic references to "wild horses," may actually refer to feral domestic horses or hybrids. Some 19th-century authors wrote that local "wild" horses had hoof problems, leading to crippled legs, and thus they assumed these were feral horses. Other contemporary authors claimed all "wild" horses between the Volga River and the Ural were actually feral. However, others thought that this was too speculative and assumed that wild, undomesticated horses still lived into the 19th century. Domestic horses used in warfare often were turned loose when they were not needed. Also, remaining wild stallions could steal domestic mares. There are some accounts from the 18th and 19th century of wild herds with typical wild horse features such as large heads, pinned ears, short frizzy mane and tail, but mentioned animals with domestic influence as well.
The only known individual to be photographed was the so-called Cherson-Tarpan, which was caught as a foal near Novovorontsovka in 1866. It died in 1887 in the Moscow Zoo. The nature of this horse was dubious in its lifetime, because it showed almost none of the wild horse features described in the historic sources. Today it is assumed this individual either was a hybrid or a feral domestic horse.
Three attempts have been made to use selective breeding to create a type of horse that resembles the Tarpan phenotype, though recreating an extinct subspecies is not genetically possible with current technology. In 1936, Polish university professor Tadeusz Vetulani selected Polish farm horses that he believed resembled the historic Tarpan and started a selective breeding program. This horse breed is now called the Konik, which clusters genetically with other domestic horse breeds, including those as diverse as the Mongolian horse and the Thoroughbred. In the early 1930s, Berlin Zoo Director Lutz Heck and Heinz Heck of the Munich Zoo began a program crossbreeding Koniks with Przewalski horses, Gotland Ponies, and Icelandic horses. By the 1960s they produced the Heck horse. In the mid-1960s, Harry Hegard started a similar program in the United States using Mustangs and local working ranch horses that has resulted in the Hegardt or Stroebel's Horse.
While all three breeds have a primitive look that resembles the wild type Tarpan in some respects, they are not genetically Tarpans and the wild, pre-domestic European horse remains extinct. However, this does not prevent some modern breeders from marketing horses with these features as a "Tarpan." In spite of sharing primitive external features, the Konik and Hucul horses have markedly different conformation with differently-proportioned body measurements, thought in part to be linked to living in different habitats. Other breeds sometimes alleged to be surviving Tarpans include the Exmoor Pony and the Dülmen Pony. However, genetic studies do not set any of these breeds apart from other domestic horses. On the other hand, there has not yet been a study comparing domestic breeds directly with the European wild horse.
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The wild horse (Equus ferus) is a species of the genus Equus, which includes as subspecies the modern domesticated horse (Equus ferus caballus) as well as the undomesticated Tarpan (Equus ferus ferus), now extinct, and the endangered Przewalski's horse (Equus ferus przewalskii). The Przewalski's Horse was saved from the brink of extinction and reintroduced successfully to the wild. The Tarpan became extinct in the 19th century, though it was a possible ancestor of the domestic horse, and roamed the steppes of Eurasia at the time of domestication. However, other subspecies of Equus ferus may have existed and could have been the stock from which domesticated horses are descended. Since the extinction of the Tarpan, attempts have been made to reconstruct its phenotype, resulting in horse breeds such as the Konik and Heck horse. However, the genetic makeup and foundation bloodstock of those breeds is substantially derived from domesticated horses, and therefore these breeds possess domesticated traits.
The term "wild horse" is also used colloquially to refer to free-roaming herds of feral horses such as the Mustang in the United States, the Brumby in Australia, and many others. These feral horses are untamed members of the domestic horse subspecies (Equus ferus caballus), and should not be confused with the two truly "wild" horse subspecies.
Subspecies and their history
E. ferus had several subspecies. Three survived into modern times:
- The Domestic horse (Equus ferus caballus).
- The Tarpan or Eurasian Wild Horse (Equus ferus ferus), once native to Europe and western Asia. The Tarpan became effectively extinct in the late 19th century, and the last specimen died in captivity in an estate in Poltava Governorate, Russian Empire, in 1909.
- Przewalski's horse (Equus ferus przewalskii), also known as the Mongolian Wild Horse or Takhi, native to Central Asia and the Gobi Desert.
The latter two are the only never-domesticated "wild" groups that survived into historic times. However, other subspecies of Equus ferus may have existed and could have been the stock from which domesticated horses are descended.
Przewalski's Horse occupied the eastern Eurasian steppes, perhaps from the Urals to Mongolia, although the ancient border between Tarpan and Przewalski distributions has not been clearly defined. Przewalski's Horse was limited to Dzungaria and western Mongolia in the same period, and became extinct in the wild during the 1960s, but was re-introduced in the late 1980s to two preserves in Mongolia. Although researchers such as Marija Gimbutas theorized that the horses of the Chalcolithic period were Przewalski's, more recent genetic studies indicate that Przewalski's Horse is not an ancestor to modern domesticated horses.
Przewalski's Horse is still found today, though it is an endangered species and for a time was considered extinct in the wild. Roughly 1500 Przewalski's Horses are in zoos around the world. A small breeding population has been reintroduced in Mongolia. As of 2005, a cooperative venture between the Zoological Society of London and Mongolian scientists has resulted in a free-ranging population of 248 animals in the wild.
Przewalski's Horse has some biological differences from the domestic horse; unlike domesticated horses and the Tarpan, which both have 64 chromosomes, Przewalski's Horse has 66 chromosomes due to a Robertsonian translocation. However, the offspring of Przewalski and domestic horses are fertile, possessing 65 chromosomes.
Evolution and taxonomy
The horse family Equidae and the genus Equus evolved in North America, before the species moved into the Eastern Hemisphere. Studies using ancient DNA as well as DNA of recent individuals, shows the presence of two closely related horse species in North America, the Wild Horse and the "New World stilt-legged horse;" the latter is taxonomically assigned to various names.   Currently, three subspecies that lived during recorded human history are recognized. One subspecies is the widespread domestic horse (Equus ferus caballus), as well as two wild subspecies, the recently extinct Tarpan (Equus ferus ferus) and the endangered Przewalski's Horse (Equus ferus przewalskii).   Genetically, the pre-domestication horse, Equus ferus ferus, and domesticated horse, Equus ferus caballus, form a single homogeneous group (clade) and are genetically indistinguishable from each other.  The genetic variation within this clade shows only a limited regional variation, with a notable exception of Przewalski's Horse. Przewalski's Horse has several unique genetic differences that distinguishes it from the other subspecies, including 66 instead of 64 chromosomes,  unique Y-chromosome gene haplotypes,  and unique mtDNA haplotypes.  Besides genetic differences, osteological evidence from across the Eurasian wild horse range, based on cranial and metacarpal differences, indicates the presence of only two subspecies in post-glacial times, the Tarpan and Przewalski's Horse. 
Scientific naming of the species
At present, the domesticated and wild horses are considered a single species, with the valid scientific name for the horse species being Equus ferus. The wild Tarpan subspecies is Equus ferus ferus, Przewalski's Horse is Equus ferus przewalskii, and the domesticated horse is Equus ferus caballus. The rules for the scientific naming of animal species are determined in the International Code of Zoological Nomenclature, which stipulates that the oldest available valid scientific name is used to name the species. Previously, when taxonomists considered domesticated and wild horse two subspecies of the same species, the valid scientific name was Equus caballus Linnaeus 1758, with the subspecies labeled Equus caballus caballus (domesticated horse), Equus caballus ferus Boddaert, 1785 (tarpan) and Equus caballus przewalskii Poliakov, 1881 (Przewalski's Horse). However, in 2003, the International Commission on Zoological Nomenclature decided that the scientific names of the wild species have priority over the scientific names of domesticated species, therefore mandating the use of Equus ferus for the horse, independent of the position of the domesticated horse.
Horses that live in an untamed state but have ancestors who have been domesticated are not truly "wild" horses; they are feral horses. For example, when the Spanish reintroduced the horse to the Americas beginning in the late 15th century, some horses escaped and formed feral herds, the best-known being the Mustang. The Australian equivalent to the Mustang is the Brumby, descended from horses strayed or let loose in Australia by English settlers. There are isolated populations of feral horses in a number of places, including Portugal, Scotland, and a number of barrier islands along the Atlantic coast of North America from Sable Island off Nova Scotia, to the Shackleford Banks of North Carolina. While these are often referred to as "wild" horses, they are not truly "wild" in the biological sense of having no domesticated ancestors.
In 1995, British and French explorers discovered a new population of horses in the Riwoche Valley of Tibet, unknown to the rest of the world, but apparently used by the local Khamba people. It was speculated that the Riwoche horse might be a relict population of wild horses, but testing did not reveal genetic differences with domesticated horses, which is in line with news reports indicating that they are used as pack and riding animals by the local villagers. These horses only stand 12 hands (48 inches, 122 cm) tall and are said to resemble the images known as "horse no 2" depicted in cave paintings alongside images of Przewalski's horse.
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