Wild horse#Distribution

Wild horses were formerly widespread across the Old World during the Late Pleistocene and early Holocene, occurring from Western Europe and North Africa (where remains are referred to as Equus algericus), to the far north of Siberia (where they are referred to as Equus lenensis) to East Asia.{{Cite journal |last1=Cirilli |first1=Omar |last2=Machado |first2=Helena |last3=Arroyo-Cabrales |first3=Joaquin |last4=Barrón-Ortiz |first4=Christina I. |last5=Davis |first5=Edward |last6=Jass |first6=Christopher N. |last7=Jukar |first7=Advait M. |last8=Landry |first8=Zoe |last9=Marín-Leyva |first9=Alejandro H. |last10=Pandolfi |first10=Luca |last11=Pushkina |first11=Diana |last12=Rook |first12=Lorenzo |last13=Saarinen |first13=Juha |last14=Scott |first14=Eric |last15=Semprebon |first15=Gina |display-authors=3 |date=2022-08-24 |title=Evolution of the Family Equidae, Subfamily Equinae, in North, Central and South America, Eurasia and Africa during the Plio-Pleistocene |journal=Biology |language=en |volume=11 |issue=9 |pages=1258 |doi=10.3390/biology11091258 |doi-access=free |issn=2079-7737 |pmc=9495906 |pmid=36138737}} Today the only living wild horse subspecies, Przewalski's horse, which was formerly extinct in the wild, has been reintroduced to small areas spanning from its former distribution in northeast China, Mongolia{{Cite journal |last1=Ji |first1=Shengnan |last2=Zhu |first2=Yanpeng |last3=Cui |first3=Shaopeng |last4=Deng |first4=Huaiqing |last5=Li |first5=Chunwang |display-authors=3 |date=September 2022 |title=The road home for Przewalski's horse in China |journal=Oryx |language=en |volume=56 |issue=5 |pages=652 |doi=10.1017/S0030605322000758 |issn=0030-6053|doi-access=free }} and Kazakhstan,{{Cite web |date=6 June 2024 |title=Przewalski's horses return to central Kazakhstan after nearly 200-year absence |url=https://fzs.org/en/news/przewalskis-horses-return-to-kazakhstan/ |website=Frankfurt Zoological Society}} as well as areas outside of its historical distribution, including Spain.{{Cite web |date=2023-11-30 |title=La renaturalización trae al Alto Tajo los únicos caballos Przewalski que pastarán en libertad en Europa Occidental |url=https://rewilding-spain.com/en/news/rewilding-brings-to-the-iberian-highlands-the-first-free-roaming-przewalskis-horses-in-western-europe/ |access-date=2024-05-05 |website=Rewilding Spain |language=en-GB}}

{{See also|Horse#Anatomy}}

Across time and space, wild horses show considerable variability in body size and limb dimensions, likely as adaptations to local environmental and climatic conditions.{{Cite journal |last=van Asperen |first=Eline Naomi |date=November 2010 |title=Ecomorphological adaptations to climate and substrate in late Middle Pleistocene caballoid horses |url=https://linkinghub.elsevier.com/retrieve/pii/S0031018210005572 |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |language=en |volume=297 |issue=3–4 |pages=584–596 |doi=10.1016/j.palaeo.2010.09.007|bibcode=2010PPP...297..584V |url-access=subscription }}{{Cite journal |last1=Saarinen |first1=Juha |last2=Cirilli |first2=Omar |last3=Strani |first3=Flavia |last4=Meshida |first4=Keiko |last5=Bernor |first5=Raymond L. |display-authors=3 |date=2021-02-26 |title=Testing Equid Body Mass Estimate Equations on Modern Zebras—With Implications to Understanding the Relationship of Body Size, Diet, and Habitats of Equus in the Pleistocene of Europe |journal=Frontiers in Ecology and Evolution |volume=9 |doi=10.3389/fevo.2021.622412 |doi-access=free |bibcode=2021FrEEv...922412S |issn=2296-701X|hdl=11573/1505920 |hdl-access=free }} The living Przewalski's horse has an estimated body mass of {{Convert|250-360|kg}},{{Cite web |title=Przewalski's horse |url=https://nationalzoo.si.edu/animals/przewalskis-horse |access-date=2024-12-09 |website=Smithsonian's National Zoo and Conservation Biology Institute |language=en}} though the body mass of Przewalski's horse varies considerably according to rhythmic annual cycles.{{Cite journal |last1=Scheibe |first1=Klaus M. |last2=Streich |first2=Wolf J. |date=October 2003 |title=Annual Rhythm of Body Weight in Przewalski Horses (Equus ferus przewalskii) |url=https://www.tandfonline.com/doi/full/10.1076/brhm.34.4.383.26227 |journal=Biological Rhythm Research |language=en |volume=34 |issue=4 |pages=383–395 |doi=10.1076/brhm.34.4.383.26227 |bibcode=2003BioRR..34..383S |issn=0929-1016|url-access=subscription }} Some extinct wild horse populations are thought to have been considerably larger, with some Pleistocene European wild horses (including those assigned to Equus (ferus) mosbachensis and Equus (ferus) latipes) suggested to have body masses of around {{Convert|500-607|kg|}}.{{Cite journal |last=Pushkina |first=Diana |date=2024-11-19 |title=Paleoecology and body mass distribution of horses in northern Eurasia during the Pleistocene |url=https://bioone.org/journals/annales-zoologici-fennici/volume-61/issue-1/086.061.0118/Paleoecology-and-body-mass-distribution-of-horses-in-northern-Eurasia/10.5735/086.061.0118.full |journal=Annales Zoologici Fennici |volume=61 |issue=1 |doi=10.5735/086.061.0118 |issn=0003-455X|url-access=subscription }}{{Cite journal |last1=Nacarino-Meneses |first1=Carmen |last2=Orlandi-Oliveras |first2=Guillem |date=2021-05-04 |title=The life history of European Middle Pleistocene equids: first insights from bone histology |url=https://www.tandfonline.com/doi/full/10.1080/08912963.2019.1655011 |journal=Historical Biology |language=en |volume=33 |issue=5 |pages=672–682 |doi=10.1080/08912963.2019.1655011 |bibcode=2021HBio...33..672N |issn=0891-2963}}^ST2 Earlier Middle Pleistocene horses (such as those assigned to E. (ferus) mosbachensis) differ from later ones in some aspects of the anatomy of the limbs and teeth.

Wild horses show considerable environmental tolerances, having historically inhabited environments ranging from temperate forest to steppe (including the prehistoric mammoth steppe biome{{Cite journal |last1=Schwartz-Narbonne |first1=R. |last2=Longstaffe |first2=F.J. |last3=Kardynal |first3=K.J. |last4=Druckenmiller |first4=P. |last5=Hobson |first5=K.A. |last6=Jass |first6=C.N. |last7=Metcalfe |first7=J.Z. |last8=Zazula |first8=G. |display-authors=3 |date=July 2019 |title=Reframing the mammoth steppe: Insights from analysis of isotopic niches |url=https://linkinghub.elsevier.com/retrieve/pii/S0277379118302646 |journal=Quaternary Science Reviews |language=en |volume=215 |pages=1–21 |doi=10.1016/j.quascirev.2019.04.025|bibcode=2019QSRv..215....1S |url-access=subscription }}) and tundra,{{cite journal |last1=Boeskorov |first1=Gennady G. |last2=Potapova |first2=Olga R. |last3=Protopopov |first3=Albert V. |last4=Plotnikov |first4=Valery V. |last5=Maschenko |first5=Eugeny N. |last6=Shchelchkova |first6=Marina V. |last7=Petrova |first7=Ekaterina A. |last8=Kowalczyk |first8=Rafal |last9=van der Plicht |first9=Johannes |last10=Tikhonov |first10=Alexey N. |display-authors=3 |date=July 2018 |title=A study of a frozen mummy of a wild horse from the Holocene of Yakutia, east Siberia, Russia |journal=Mammal Research |volume=63 |issue=3 |pages=307–314 |doi=10.1007/s13364-018-0362-4 |issn=2199-241X |url=https://pure.rug.nl/ws/files/76631990/Boeskorov2018_Article_AStudyOfAFrozenMummyOfAWildHor.pdf |lang=en |df=dmy-all}} though in general they tend to show a preference for open environments.{{Cite journal |last1=Sommer |first1=Robert S. |last2=Benecke |first2=Norbert |last3=Lõugas |first3=Lembi |last4=Nelle |first4=Oliver |last5=Schmölcke |first5=Ulrich |display-authors=3 |date=November 2011 |title=Holocene survival of the wild horse in Europe: a matter of open landscape? |url=https://onlinelibrary.wiley.com/doi/10.1002/jqs.1509 |journal=Journal of Quaternary Science |language=en |volume=26 |issue=8 |pages=805–812 |doi=10.1002/jqs.1509 |bibcode=2011JQS....26..805S |issn=0267-8179}} Horses are typically considered to be grazers. They may have seasonal food preferences, as seen in the Przewalski's horse,{{Cite journal|url=http://www.pol.j.ecol.cbe-pan.pl/article/ar59_4_19.pdf|access-date=29 October 2013|archive-url=https://web.archive.org/web/20131029185432/http://www.pol.j.ecol.cbe-pan.pl/article/ar59_4_19.pdf|archive-date=2013-10-29|author1=Kateryna Slivinska|author2=Grzegorz Kopij|title=Diet of the Przewalski's horse Equus przewalskii in the Chernobyl Exclusion Zone|journal=Polish Journal of Ecology|volume=59|issue=4|pages=841–847|date=2011}} which historically consumed browse like shrubs during the winter months due to being forced into suboptimal habitat by human pressure.{{Cite journal |last1=Kaczensky |first1=Petra |last2=Burnik Šturm |first2=Martina |last3=Sablin |first3=Mikhail V. |last4=Voigt |first4=Christian C. |last5=Smith |first5=Steve |last6=Ganbaatar |first6=Oyunsaikhan |last7=Balint |first7=Boglarka |last8=Walzer |first8=Chris |last9=Spasskaya |first9=Natalia N. |display-authors=3 |date=2017-07-20 |title=Stable isotopes reveal diet shift from pre-extinction to reintroduced Przewalski's horses |journal=Scientific Reports |language=en |volume=7 |issue=1 |page=5950 |doi=10.1038/s41598-017-05329-6 |issn=2045-2322 |pmc=5519547 |pmid=28729625|bibcode=2017NatSR...7.5950K }} Some extinct Pleistocene wild horse populations that inhabited forested environments show dental wear suggesting them to have been mixed feeders or even predominantly browsers during certain times of the year, though this may be reflecting the consumption of low growing forbs rather than shrubs.{{Cite journal |last1=Rivals |first1=Florent |last2=Julien |first2=Marie-Anne |last3=Kuitems |first3=Margot |last4=Van Kolfschoten |first4=Thijs |last5=Serangeli |first5=Jordi |last6=Drucker |first6=Dorothée G. |last7=Bocherens |first7=Hervé |last8=Conard |first8=Nicholas J. |display-authors=3 |date=December 2015 |title=Investigation of equid paleodiet from Schöningen 13 II-4 through dental wear and isotopic analyses: Archaeological implications |url=https://linkinghub.elsevier.com/retrieve/pii/S0047248414000840 |journal=Journal of Human Evolution |language=en |volume=89 |pages=129–137 |doi=10.1016/j.jhevol.2014.04.002|pmid=25242064 |bibcode=2015JHumE..89..129R |url-access=subscription }}{{Cite journal |last1=Rivals |first1=Florent |last2=Lister |first2=Adrian M. |date=August 2016 |title=Dietary flexibility and niche partitioning of large herbivores through the Pleistocene of Britain |url=https://linkinghub.elsevier.com/retrieve/pii/S0277379116302086 |journal=Quaternary Science Reviews |language=en |volume=146 |pages=116–133 |doi=10.1016/j.quascirev.2016.06.007|bibcode=2016QSRv..146..116R |url-access=subscription }}

Wild horses live in herds with a social hierarchy,{{Cite journal |last1=Tatin |first1=L. |last2=King |first2=S. R. B. |last3=Munkhtuya |first3=B. |last4=Hewison |first4=A. J. M. |last5=Feh |first5=C. |display-authors=3 |date=February 2009 |title=Demography of a socially natural herd of Przewalski's horses: an example of a small, closed population |url=https://zslpublications.onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2008.00520.x |journal=Journal of Zoology |language=en |volume=277 |issue=2 |pages=134–140 |doi=10.1111/j.1469-7998.2008.00520.x |issn=0952-8369|url-access=subscription }} formed by a dominant adult male or sometimes multiple males (harem stallions), as well as several mares and their offspring. The harem stallion aggressively defends his herd/harem against rival males.{{Cite journal |last1=Bernátková |first1=Anna |last2=Ceacero |first2=Francisco |last3=Oyunsaikhan |first3=Ganbaatar |last4=Sukhbaatar |first4=Dalaitseren |last5=Šimek |first5=Jaroslav |last6=Komárková |first6=Martina |display-authors=3 |date=June 2023 |title=Novel observation of play behaviour between a harem holder and a bachelor group of Przewalski's horses in the wild |journal=Acta Ethologica |language=en |volume=26 |issue=2 |pages=145–150 |doi=10.1007/s10211-023-00421-9 |issn=0873-9749|doi-access=free }} Upon reaching adulthood, both male and female horses disperse to other herds to avoid inbreeding, with young adult males also forming bachelor groups when they are around 3 years of age. In bachelor groups male horses engage in play and ritual behaviour, with the group forming a hierarchy.{{Cite journal |last1=Bourjade |first1=M. |last2=Tatin |first2=L. |last3=King |first3=S.R.B. |last4=Feh |first4=C. |date=January 2009 |title=Early reproductive success, preceding bachelor ranks and their behavioural correlates in young Przewalski's stallions |url=http://www.tandfonline.com/doi/abs/10.1080/08927014.2009.9522507 |journal=Ethology Ecology & Evolution |language=en |volume=21 |issue=1 |pages=1–14 |doi=10.1080/08927014.2009.9522507 |bibcode=2009EtEcE..21....1B |issn=0394-9370|url-access=subscription }} Mare Przewalski's horses tend to begin giving birth around 3 years of age,{{Cite journal |last1=Rödel |first1=Heiko G. |last2=Ibler |first2=Benjamin |last3=Ozogány |first3=Katalin |last4=Kerekes |first4=Viola |date=December 2023 |title=Age-specific effects of density and weather on body condition and birth rates in a large herbivore, the Przewalski's horse |journal=Oecologia |language=en |volume=203 |issue=3–4 |pages=435–451 |doi=10.1007/s00442-023-05477-9 |issn=0029-8549 |pmc=10684615 |pmid=37971561|bibcode=2023Oecol.203..435R }} with a gestation period of around 12 months, primarily giving birth in the spring or summer.{{Cite journal |last1=Chen |first1=Jinliang |last2=Weng |first2=Qiang |last3=Chao |first3=Jie |last4=Hu |first4=Defu |last5=Taya |first5=Kazuyoshi |display-authors=3 |date=2008 |title=Reproduction and Development of the Released Przewalski's Horses (Equus przewalskii) in Xinjiang, China |url=http://www.jstage.jst.go.jp/article/jes/19/1/19_1_1/_article |journal=Journal of Equine Science |language=en |volume=19 |issue=1 |pages=1–7 |doi=10.1294/jes.19.1 |issn=1340-3516 |pmc=4019202 |pmid=24833949}} Przewalski's stallions generally leave batchelor groups to begin breeding at around 5–6 years of age.

In modern times the main predator of wild horses in Eurasia are wolves,{{Cite journal |last1=Usukhjargal |first1=Dorj |last2=Henkens |first2=RenéJ H. G. |last3=Boer |first3=Willem F. de |last4=Vos |first4=Anneleen E. W. de |last5=Ras |first5=Erica |last6=Duyne |first6=Caroline van |display-authors=3 |date=28 August 2009 |title=Wolf Predation Among Reintroduced Przewalski Horses in Hustai National Park, Mongolia |journal=Journal of Wildlife Management |volume=73 |issue=6 |pages=836–843 |doi=10.2193/2008-027 |bibcode=2009JWMan..73..836D |s2cid=85877321}} though during the Pleistocene they had other predators such as cave hyenas.{{Cite journal |last=Diedrich |first=Cajus G. |date=15 June 2010 |title=Specialized horse killers in Europe: Foetal horse remains in the Late Pleistocene Srbsko Chlum-Komín Cave hyena den in the Bohemian Karst (Czech Republic) and actualistic comparisons to modern African spotted hyenas as zebra hunters |url=https://linkinghub.elsevier.com/retrieve/pii/S1040618210000443 |journal=Quaternary International |language=en |volume=220 |issue=1–2 |pages=174–187 |doi=10.1016/j.quaint.2010.01.023|bibcode=2010QuInt.220..174D |url-access=subscription }}

E. ferus has had several subspecies; those which survived into modern times are:{{cite book|title=Mammal Species of the World. A Taxonomic and Geographic Reference|editor1=Don E. Wilson|editor2=DeeAnn M. Reeder|publisher=Johns Hopkins University Press|year=2005|edition=3rd|chapter=Equus caballus|chapter-url=https://www.departments.bucknell.edu/biology/resources/msw3/browse.asp?id=14100015|access-date=2009-02-12}}

• The domesticated horse (Equus ferus caballus).
• The Eurasian wild horse (Equus ferus ferus), incorrectly listed as Equus caballus ferus in MSW 3; originally considered synonymous with the tarpan, though recent research has cast doubt on this. Horses identified as tarpans were found in Europe and western Asia before the last surviving animals —possibly hybrids by that time — became effectively extinct in the late 19th century. The last specimen died in 1909 whilst in captivity in an estate in Poltava Governorate, Russian Empire.
• Przewalski's horse (Equus ferus przewalskii), incorrectly listed as Equus caballus przewalskii in MSW 3; also known as the Mongolian wild horse or takhi, it is native to Central Asia and the Gobi Desert. It is sometimes considered its own species, Equus przewalskii.

The latter two are the only never-domesticated "wild" groups that survived into historic times. However, other subspecies of Equus ferus may have existed.{{cite book | first=Colin | last=Groves | date=1986 | chapter=The taxonomy, distribution, and adaptations of recent Equids | editor-first1 = Richard H. | editor-last1=Meadow | editor-first2=Hans-Peter | editor-last2=Uerpmann | title=Equids in the Ancient World, volume I | pages=11–65 | location=Wiesbaden | publisher=Ludwig Reichert Verlag}}

In the Late Pleistocene epoch, there were several other subspecies of E. ferus which have all since gone extinct. The exact categorization of Equus remains into species or subspecies is a complex matter and the subject of ongoing work.{{Cite journal|title=Biostratigraphy and Palaeoecology of European Equus|journal=Frontiers in Ecology and Evolution|last1=Boulbes|first1=Nicolas|date=2019|volume=7|page=301|last2=van Asperen|first2=Eline N.|doi=10.3389/fevo.2019.00301|issn=2296-701X|doi-access=free|bibcode=2019FrEEv...7..301B }}

File:Equus ferus.jpg, at the Zoological Museum in Copenhagen]]

{{main|Evolution of the horse}}The horse family Equidae evolved in North America, with the genus Equus appearing on the continent during the Pliocene (5.3-2.6 million years ago).{{cite journal|url=http://www.cabi.org/isc/datasheet/119345|title=Equus caballus [ISC] (horse)|journal=Cabi Compendium|date=2022 |doi=10.1079/cabicompendium.119345 |last1=Beever |first1=Erik A. |volume=CABI Compendium |doi-access=free }} Horses are thought to have diverged from the ancestors of zebras and asses around 4 million years ago.{{Cite journal |last1=Cai |first1=Dawei |last2=Zhu |first2=Siqi |last3=Gong |first3=Mian |last4=Zhang |first4=Naifan |last5=Wen |first5=Jia |last6=Liang |first6=Qiyao |last7=Sun |first7=Weilu |last8=Shao |first8=Xinyue |last9=Guo |first9=Yaqi |last10=Cai |first10=Yudong |last11=Zheng |first11=Zhuqing |last12=Zhang |first12=Wei |last13=Hu |first13=Songmei |last14=Wang |first14=Xiaoyang |last15=Tian |first15=He |display-authors=3 |date=2022-05-11 |title=Radiocarbon and genomic evidence for the survival of Equus Sussemionus until the late Holocene |journal=eLife |language=en |volume=11 |doi=10.7554/eLife.73346 |doi-access=free |issn=2050-084X |pmc=9142152 |pmid=35543411}} Around 900–800,000 years ago, at the Early-Middle Pleistocene boundary, the ancestors of Eurasian wild horses crossed over the Bering Land Bridge from North America.{{Cite journal |last1=Vershinina |first1=Alisa O. |last2=Heintzman |first2=Peter D. |last3=Froese |first3=Duane G. |last4=Zazula |first4=Grant |last5=Cassatt-Johnstone |first5=Molly |last6=Dalén |first6=Love |last7=Der Sarkissian |first7=Clio |last8=Dunn |first8=Shelby G. |last9=Ermini |first9=Luca |last10=Gamba |first10=Cristina |last11=Groves |first11=Pamela |last12=Kapp |first12=Joshua D. |last13=Mann |first13=Daniel H. |last14=Seguin-Orlando |first14=Andaine |last15=Southon |first15=John |display-authors=3 |date=December 2021 |title=Ancient horse genomes reveal the timing and extent of dispersals across the Bering Land Bridge |url=https://onlinelibrary.wiley.com/doi/10.1111/mec.15977 |journal=Molecular Ecology |language=en |volume=30 |issue=23 |pages=6144–6161 |doi=10.1111/mec.15977 |pmid=33971056 |bibcode=2021MolEc..30.6144V |hdl=10037/24463 |issn=0962-1083|hdl-access=free }} Early horses in Eurasia are referred to species like Equus mosbachensis. North American caballine horses, which genetic evidence has confirmed are closely related to Eurasian horses, would persist on the continent until they became extinct as part of the end-Pleistocene extinction event along with most other large mammals in the Americas (including other equines like Haringtonhippus and Hippidion) around 12,000 years ago. They are variously referred to as Equus scotti and Equus lambei though the true number of species is uncertain, with some authors treating all North American horses as part of E. ferus. Ancient DNA analysis suggests North American horses were largely genetically distinct from Eurasian horses, with limited and intermittent interbreeding between the two populations following the initial dispersal across the Bering Land Bridge. Equus neogeus from the Pleistocene of South America may also represent a lineage of true caballine horses.{{Cite journal |last1=Barrón-Ortiz |first1=Christina I. |last2=Avilla |first2=Leonardo S. |last3=Jass |first3=Christopher N. |last4=Bravo-Cuevas |first4=Víctor M. |last5=Machado |first5=Helena |last6=Mothé |first6=Dimila |display-authors=3 |date=2019-09-12 |title=What Is Equus? Reconciling Taxonomy and Phylogenetic Analyses |journal=Frontiers in Ecology and Evolution |volume=7 |pages=343 |doi=10.3389/fevo.2019.00343 |issn=2296-701X |doi-access=free|bibcode=2019FrEEv...7..343B }}

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 European wild horse (E. f. ferus) and the endangered Przewalski's horse (E. f. przewalskii).{{cite book|last=Groves|first=Colin P. |title=The Przewalski Horse: Morphology, Habitat and Taxonomy |editor=Boyd, Lee and Katherine A. Houpt|publisher=State University of New York Press|location=Albany, New YorkColin P. Groves|year=1994|volume=Przewalski's Horse: The History and Biology of an Endangered Species.|url=http://www.noanswersingenesis.org.au/cg_przewalski_horse.htm}}{{cite journal|last=Kavar |first=Tatjana |author2=Peter Dovč |year=2008|title=Domestication of the horse: Genetic relationships between domestic and wild horses|journal=Livestock Science|volume=116 |issue=1–3 |pages=1–14 |doi=10.1016/j.livsci.2008.03.002}} A 2015 study determined that the Przewalski and domesticated horse lineages diverged from a common ancestor about 45,000 years ago.{{cite journal |last1=Der Sarkissian |first1=Clio |last2=Ermini |first2=Luca |last3=Schubert |first3=Mikkel |last4=Yang |first4=Melinda A. |last5=Librado |first5=Pablo |last6=Fumagalli |first6=Matteo |last7=Jónsson |first7=Hákon |last8=Bar-Gal |first8=Gila Kahila |last9=Albrechtsen |first9=Anders |last10=Vieira |first10=Filipe G. |last11=Petersen |first11=Bent |last12=Ginolhac |first12=Aurélien |last13=Seguin-Orlando |first13=Andaine |last14=Magnussen |first14=Kim |last15=Fages |first15=Antoine |display-authors=3 |date=October 2015 |title=Evolutionary Genomics and Conservation of the Endangered Przewalski's Horse |journal=Current Biology |volume=25 |issue=19 |pages=2577–2583 |bibcode=2015CBio...25.2577D |doi=10.1016/j.cub.2015.08.032 |pmc=5104162 |pmid=26412128 |hdl-access=free |last16=Gamba |first16=Cristina |last17=Lorente-Galdos |first17=Belen |last18=Polani |first18=Sagi |last19=Steiner |first19=Cynthia |last20=Neuditschko |first20=Markus |last21=Jagannathan |first21=Vidhya |last22=Feh |first22=Claudia |last23=Greenblatt |first23=Charles L. |last24=Ludwig |first24=Arne |last25=Abramson |first25=Natalia I. |last26=Zimmermann |first26=Waltraut |last27=Schafberg |first27=Renate |last28=Tikhonov |first28=Alexei |last29=Sicheritz-Ponten |first29=Thomas |last30=Willerslev |first30=Eske |last31=Marques-Bonet |first31=Tomas |last32=Ryder |first32=Oliver A. |last33=McCue |first33=Molly |last34=Rieder |first34=Stefan |last35=Leeb |first35=Tosso |last36=Slatkin |first36=Montgomery |last37=Orlando |first37=Ludovic |hdl=10230/33065}}

Genetically, the pre-domestication horse, E. ferus, and the domesticated horse, E. caballus, form a single homogeneous group (clade) and are genetically indistinguishable from each other.{{cite journal |last=Weinstock |first=J. |display-authors=etal |year=2005 |title=Evolution, systematics, and phylogeography of Pleistocene horses in the New World: a molecular perspective |journal=PLOS Biology |volume=3 |issue=8 |pages=e241 |doi=10.1371/journal.pbio.0030241 |pmc=1159165 |pmid=15974804 |doi-access=free}}{{cite journal |last1=Orlando |first1=Ludovic |last2=Male |first2=Dean |last3=Alberdi |first3=Maria Teresa |last4=Prado |first4=Jose Luis |last5=Prieto |first5=Alfredo |last6=Cooper |first6=Alan |last7=Hänni |first7=Catherine |display-authors=3 |date=9 April 2008 |title=Ancient DNA Clarifies the Evolutionary History of American Late Pleistocene Equids |journal=Journal of Molecular Evolution |volume=66 |issue=5 |pages=533–538 |bibcode=2008JMolE..66..533O |doi=10.1007/s00239-008-9100-x |pmid=18398561 |s2cid=19069554}}{{cite journal|last=Vilà|first=Carles|author2=Jennifer A. Leonard |author3=Anders Götherström |author4=Stefan Marklund |author5=Kaj Sandberg |author6=Kerstin Lidén |author7=Robert K. Wayne |author8=Hans Ellegren |display-authors=3 |year=2001|title=Widespread Origins of Domestic Horse Lineages |journal=Science|volume=291|issue=5503|pages=474–477|doi=10.1126/science.291.5503.474|pmid=11161199|bibcode=2001Sci...291..474V|s2cid=15514589|url=http://pdfs.semanticscholar.org/5a2e/a78566b4a4b36c77147434c15ecdb086fe28.pdf|archive-url=https://web.archive.org/web/20200705124756/http://pdfs.semanticscholar.org/5a2e/a78566b4a4b36c77147434c15ecdb086fe28.pdf|archive-date=2020-07-05}} The genetic variation within this clade shows only a limited regional variation, with the notable exception of Przewalski's horse.{{cite journal|last=Cai|first=Dawei |author2=Zhuowei Tang |author3=Lu Han |author4=Camilla F. Speller |author5=Dongya Y. Yang |author6=Xiaolin Ma |author7=Jian'en Cao |author8=Hong Zhu |author9=Hui Zhou |display-authors=3 |year=2009|title=Ancient DNA provides new insights into the origin of the Chinese domestic horse |journal=Journal of Archaeological Science|volume=36|issue=3|pages=835–842|doi=10.1016/j.jas.2008.11.006|bibcode=2009JArSc..36..835C }} Przewalski's horse has several unique genetic differences that distinguish it from the other subspecies, including 66 instead of 64 chromosomes,{{cite journal|last=Benirschke|first=Poliakoff K. |author2=N. Malouf |author3=R. J. Low |author4=H. Heck |date=16 April 1965|title=Chromosome Complement: Differences between Equus caballus and Equus przewalskii|journal=Science |volume=148 |issue=3668 |pages=382–383 |doi=10.1126/science.148.3668.382 |pmid=14261533|s2cid=21562513 }} unique Y-chromosome gene haplotypes,{{cite journal|last=Lau|first=Allison |author2=Lei Peng |author3=Hiroki Goto |author4=Leona Chemnick |author5=Oliver A. Ryder |author6=Kateryna D. Makova |display-authors=3 |year=2009|title=Horse Domestication and Conservation Genetics of Przewalski's Horse Inferred from Sex Chromosomal and Autosomal Sequences|journal=Mol. Biol. Evol.|volume=26|issue=1|pages=199–208|doi=10.1093/molbev/msn239|pmid=18931383|doi-access=free}} and unique mtDNA haplotypes.{{cite journal |last1=Jansen |first1=Thomas |last2=Forster |first2=Peter |last3=Levine |first3=Marsha A. |last4=Oelke |first4=Hardy |last5=Hurles |first5=Matthew |last6=Renfrew |first6=Colin |last7=Weber |first7=Jürgen |last8=Olek |first8=Klaus |display-authors=3 |title=Mitochondrial DNA and the origins of the domestic horse |journal=Proceedings of the National Academy of Sciences |date=6 August 2002 |volume=99 |issue=16 |pages=10905–10910 |doi=10.1073/pnas.152330099 |pmid=12130666 |pmc=125071|bibcode=2002PNAS...9910905J |doi-access=free }}

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 postglacial times, the tarpan and Przewalski's horse.{{cite book|last=Eisenmann|first=Vera|title=The Horse: its domestication, diffusion and role in past communities|publisher=ABACO Edizioni|year=1998|series=Proceedings of the XIII International Congress of Prehistoric and Protohistoric Sciences, Forli, Italia, 8–14 September 1996|volume=1|pages=27–36|chapter=Quaternary Horses: possible candidates to domestication}} A study in 2011 of DNA from bones of pre-domestication horses found that all were either bay, black or leopard-spotted.{{cite journal |last1=Pruvost |first1=Melanie |last2=Bellone |first2=Rebecca |last3=Benecke |first3=Norbert |last4=Sandoval-Castellanos |first4=Edson |last5=Cieslak |first5=Michael |last6=Kuznetsova |first6=Tatyana |last7=Morales-Muñiz |first7=Arturo |last8=O'Connor |first8=Terry |last9=Reissmann |first9=Monika |last10=Hofreiter |first10=Michael |last11=Ludwig |first11=Arne |display-authors=3 |title=Genotypes of predomestic horses match phenotypes painted in Paleolithic works of cave art |journal=Proceedings of the National Academy of Sciences |date=15 November 2011 |volume=108 |issue=46 |pages=18626–18630 |doi=10.1073/pnas.1108982108 |pmid=22065780 |pmc=3219153 |bibcode=2011PNAS..10818626P |doi-access=free}}

In some sources including MSW 3 (2005), the domesticated and wild horses were considered a single species, with the valid scientific name for such a single horse species being Equus ferus,{{Cite book|url=https://books.google.com/books?id=54bgCAAAQBAJ&q=domesticated+and+wild+horses+Equus+ferus+same+species&pg=PT50|title=Equine Behaviour: Principles and Practice|last1=Mills|first1=Daniel S.|last2=Nankervis|first2=Kathryn J.|date=2013-05-20|publisher=John Wiley & Sons|isbn=978-1-118-70806-4|language=en}} although MSW erroneously used E. caballus for this (enlarged) taxon on account of a mis-interpretation of the then-recent ICZN ruling on the matter,{{cite journal|author=International Commission on Zoological Nomenclature|year=2003|title=Usage of 17 specific names based on wild species which are pre-dated by or contemporary with those based on domestic animals (Lepidoptera, Osteichthyes, Mammalia): conserved. Opinion 2027 (Case 3010).|journal=Bull. Zool. Nomencl.|volume=60|issue=1|pages=81–84}} refer Groves & Grubb, 2011.Groves, C.; Grubb, P. (2011). Ungulate Taxonomy. Baltimore, USA: Johns Hopkins University Press. p. 179. {{ISBN|978-1-4214-0093-8}} The wild tarpan subspecies is E. f. ferus, Przewalski's horse is E. f. przewalskii, while the domesticated horse is nowadays normally (but not exclusively) treated as a separate species E. 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.{{cite web|url=http://www.insecta.bio.spbu.ru/z/zoo-name.htm|title=Principles of nomenclature of zoological taxa|website=www.insecta.bio.spbu.ru|access-date=28 May 2017|archive-date=29 July 2017|archive-url=https://web.archive.org/web/20170729024156/http://www.insecta.bio.spbu.ru/z/zoo-name.htm}} Previously, when taxonomists considered domesticated and wild horse two subspecies of the same species, the valid scientific name was Equus caballus Linnaeus 1758,{{cite book | last = Linnaeus| first = Carolus| author-link = Carl Linnaeus| title = Systema naturae per regna tria naturae :secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis.| publisher = Holmiae (Laurentii Salvii) | year = 1758| page = 73| url = https://www.biodiversitylibrary.org/page/726976 | access-date = 30 January 2009 | volume = 1 | edition = 10th}} with the subspecies labeled E. c. caballus (domesticated horse), E. c. ferus Boddaert, 1785 (tarpan) and E. c. przewalskii Poliakov, 1881 (Przewalski's horse).{{Cite journal|last=Bunzel-Drüke|first=Margret|title=Ecological substitutes for Wild horse and Aurochs|url=http://www.koelner-zoo.de/takhi/PDF/Auerochs_Bunzel.pdf|journal=Natur- und Kulturlandschaft, Höxter/Jena 2001, Band 4|page=10|access-date=2017-05-28|archive-url=https://web.archive.org/web/20160303165316/http://www.koelner-zoo.de/takhi/PDF/Auerochs_Bunzel.pdf|archive-date=2016-03-03}} 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 both the wild and the domesticated horse if the two taxa are considered conspecific.{{cite journal|url=https://www.researchgate.net/publication/222518224|title=The naming of wild animal species and their domestic derivates (PDF Download Available)|journal=Journal of Archaeological Science|date=May 2004 |volume=31 |pages=645–651 |doi=10.1016/j.jas.2003.10.006 |language=en|last1=Gentry |first1=Anthea |last2=Clutton-Brock |first2=Juliet |last3=Groves |first3=Colin }}

File:Eurasian wild horse.jpg

Przewalski's horse occupied the eastern Eurasian Steppes, perhaps from the Ural Mountains to Mongolia, although the ancient border between tarpan and Przewalski's distributions has not been clearly defined.{{Cite book|url=https://books.google.com/books?id=QR4i-SwdhsoC&q=urals&pg=PA164|title=Nomadic Art of the Eastern Eurasian Steppes: The Eugene V. Thaw and Other New York Collections|last1=Bunker|first1=Emma C.|last2=Watt|first2=James C. Y.|last3=Sun|first3=Zhixin|last4=N.Y.)|first4=Metropolitan Museum of Art (New York|date=2002|publisher=Metropolitan Museum of Art|isbn=978-0-300-09688-0|language=en}} 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 reintroduced in the late 1980s to two preserves in Mongolia.{{cite web|url=http://www.waza.org/en/site/conservation/waza-conservation-projects/overview/return-of-the-wild-horse-project|title=Overview : WAZA: World Association of Zoos and Aquariums|last=WAZA|website=www.waza.org|language=en|access-date=28 May 2017|archive-date=3 June 2017|archive-url=https://web.archive.org/web/20170603024801/http://www.waza.org/en/site/conservation/waza-conservation-projects/overview/return-of-the-wild-horse-project}} Although earlier researchers such as Marija Gimbutas theorized that the horses of the Chalcolithic period were Przewalski's, a 2003 study indicated that the Przewalski's horse is not an ancestor to modern domesticated horses.{{Cite journal | last1 = Wallner | first1 = B. | last2 = Brem | first2 = G. | last3 = Müller | first3 = M. | last4 = Achmann | first4 = R. | title = Fixed nucleotide differences on the Y chromosome indicate clear divergence between Equus przewalskii and Equus caballus | doi = 10.1046/j.0268-9146.2003.01044.x | journal = Animal Genetics | volume = 34 | issue = 6 | pages = 453–456 | year = 2003 | pmid = 14687077| s2cid = 11932020 | url = http://pdfs.semanticscholar.org/80a2/49833d14c3c5ff2702f910100fc3f2c9a48e.pdf | archive-url = https://web.archive.org/web/20200706043541/http://pdfs.semanticscholar.org/80a2/49833d14c3c5ff2702f910100fc3f2c9a48e.pdf | archive-date = 2020-07-06 }}{{Cite journal | last1 = Lindgren | first1 = G. | last2 = Backström | first2 = N. | last3 = Swinburne | first3 = J. | last4 = Hellborg | first4 = L. | last5 = Einarsson | first5 = A. | last6 = Sandberg | first6 = K. | last7 = Cothran | first7 = G. | last8 = Vilà | first8 = C. | last9 = Binns | first9 = M. | doi = 10.1038/ng1326 | last10 = Ellegren | first10 = H. |display-authors=3 | title = Limited number of patrilines in horse domestication | journal = Nature Genetics | volume = 36 | issue = 4 | pages = 335–336 | year = 2004 | pmid = 15034578| doi-access = free}}

In 2018, a DNA study revealed that the horses raised for meat and milk{{cite journal |last1=Outram |first1=A.K. |last2=Stear |first2=N.A. |last3=Bendrey |first3=R. |last4=Olsen |first4=S. |last5=Kasparov |first5= A. |display-authors=3 |year=2009 |title=The earliest horse harnessing and milking |journal=Science |volume=323 |issue=5919 |pages=1332–1335 |doi=10.1126/science.1168594 |pmid=19265018|bibcode=2009Sci...323.1332O |s2cid=5126719 }} by the Botai culture 5500 years ago were Przewalski's horses. The paper claims specifically that modern Przewalski's horses are the feral descendents of the domesticated{{cite web|url=https://ore.exeter.ac.uk/repository/bitstream/handle/10871/126599/Outram%20et%20al%20Rebuttal%20of%20Taylor.pdf?sequence=1|title=Rebuttal of Taylor and Barrón-Ortiz 2021 Rethinking the evidence for early horse domestication at Botai |access-date=26 April 2024}}{{cite journal| doi=10.3389/fearc.2023.1134068| doi-access=free| title=Horse domestication as a multi-centered, multi-stage process: Botai and the role of specialized Eneolithic horse pastoralism in the development of human-equine relationships| date=2023| last1=Outram| first1=Alan K.| journal=Frontiers in Environmental Archaeology| volume=2| hdl=10871/133044| hdl-access=free}} Botai horse, although it is also possible both groups could have descended separately from the same ancient wild Przewalski's horses.{{cite journal |last1=Gaunitz |first1=Charleen |last2=Fages |first2=Antoine |last3=Hanghøj |first3=Kristian |last4=Albrechtsen |first4=Anders |last5=Khan |first5=Naveed |last6=Schubert |first6=Mikkel |last7=Seguin-Orlando |first7=Andaine |last8=Owens |first8=Ivy J. |last9=Felkel |first9=Sabine |last10=Bignon-Lau |first10=Olivier |last11=de Barros Damgaard |first11=Peter |last12=Mittnik |first12=Alissa |last13=Mohaseb |first13=Azadeh F. |last14=Davoudi |first14=Hossein |last15=Alquraishi |first15=Saleh |last16=Alfarhan |first16=Ahmed H. |last17=Al-Rasheid |first17=Khaled A. S. |last18=Crubézy |first18=Eric |last19=Benecke |first19=Norbert |last20=Olsen |first20=Sandra |last21=Brown |first21=Dorcas |last22=Anthony |first22=David |last23=Massy |first23=Ken |last24=Pitulko |first24=Vladimir |last25=Kasparov |first25=Aleksei |last26=Brem |first26=Gottfried |last27=Hofreiter |first27=Michael |last28=Mukhtarova |first28=Gulmira |last29=Baimukhanov |first29=Nurbol |last30=Lõugas |first30=Lembi |last31=Onar |first31=Vedat |last32=Stockhammer |first32=Philipp W. |last33=Krause |first33=Johannes |last34=Boldgiv |first34=Bazartseren |last35=Undrakhbold |first35=Sainbileg |last36=Erdenebaatar |first36=Diimaajav |last37=Lepetz |first37=Sébastien |last38=Mashkour |first38=Marjan |last39=Ludwig |first39=Arne |last40=Wallner |first40=Barbara |last41=Merz |first41=Victor |last42=Merz |first42=Ilja |last43=Zaibert |first43=Viktor |last44=Willerslev |first44=Eske |last45=Librado |first45=Pablo |last46=Outram |first46=Alan K. |last47=Orlando |first47=Ludovic |display-authors=3 |title=Ancient genomes revisit the ancestry of domestic and Przewalski's horses |journal=Science |date=6 April 2018 |volume=360 |issue=6384 |pages=111–114 |doi=10.1126/science.aao3297 |pmid=29472442 |bibcode=2018Sci...360..111G |doi-access=free|hdl=10871/31710 |hdl-access=free }}{{cite web|url=https://arstechnica.com/science/2018/02/ancient-dna-rules-out-archeologists-best-bet-for-horse-domestication/|date=25 February 2018|title=Ancient DNA rules out archeologists' best bet for horse domestication|publisher=ArsTechnica|access-date=24 June 2020}}

Przewalski's horse is still found today, though it is an endangered species and for a time was considered extinct in the wild.{{cite iucn|url=https://www.iucnredlist.org/details/7961/0|title=Equus ferus ssp. przewalskii (Asian Wild Horse, Mongolian Wild Horse, Przewalski's Horse)}} Roughly 2000 Przewalski's horses are in zoos around the world.{{Cite magazine |url=http://www.smithsonianmag.com/science-nature/remarkable-comeback-przewalski-horse-180961142/ |title=The Remarkable Comeback of Przewalski's Horse |last=Williams |first=Paige |magazine=Smithsonian |language=en}} A small breeding population has been reintroduced in Mongolia.{{cite web|url=http://nationalzoo.si.edu/animals/asiatrail/fact-phorse.cfm|title=Przewalski's Horse|work=si.edu|access-date=8 June 2015}}{{cite news|url=https://www.rferl.org/a/endangered-horses-back-on-russian-steppe/27607786.html|title=Endangered Przewalski's Horses Back On Russian Steppe|newspaper=Radio Free Europe/Radio Liberty|date=13 March 2016 |last1=Blua |first1=Antoine }} As of 2005, a cooperative venture between the Zoological Society of London and Mongolian scientists has resulted in a population of 248 animals in the wild.[http://www.zsl.org/info/media-centre/press-releases/null,1790,PR.html "An extraordinary return from the brink of extinction for worlds last wild horse"] {{Webarchive|url=https://web.archive.org/web/20060722122621/http://www.zsl.org/info/media-centre/press-releases/null%2C1790%2CPR.html |date=2006-07-22}} ZSL Living Conservation, 19 December 2005.

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.{{Cite book|url=https://books.google.com/books?id=RK8kRaiAvCYC&q=robertsonian+translocation&pg=PA2139|title=Equine Genomics|last=Chowdhary|first=Bhanu P.|date=2013-01-22|publisher=John Wiley & Sons|isbn=978-1-118-52212-7|language=en}} However, the offspring of Przewalski and domestic horses are fertile, possessing 65 chromosomes.[https://web.archive.org/web/20040604175246/http://biobulletin.amnh.org/D/2/3/index.html The American Museum of Natural History] When Is a Wild Horse Actually a Feral Horse?

{{Main|Feral horse|semi-feral|feral}}

{{See also|List of megafauna discovered in modern times#Status unclear}}

File:Exmoor ponies1.jpg Though popularly called "wild" horses, feral and semi-feral horses had ancestors that were domesticated.]]

Horses that live in an untamed state but have ancestors that have been domesticated are called "feral horses".{{Cite news|url=http://wonderopolis.org/wonder/are-there-still-wild-horses|title=Are There Still Wild Horses?|language=en}} For instance, when the Spanish reintroduced the horse to the Americas, beginning in the late 15th century,{{cite journal|last=Luís|first= Cristina|year=2006|title=Iberian Origins of New World Horse Breeds |journal=Journal of Heredity| volume=97|issue=2|pages=107–113 |doi=10.1093/jhered/esj020 |pmid=16489143 |display-authors=etal|doi-access=free}} some horses escaped, forming feral herds; the best-known being the mustang.{{cite web|last1=Rittman|first1=Paul|title=Spanish Colonial Horse and the Plains Indian Culture|url=http://paulrittman.com/Indian%20Culture%20and%20the%20Horse.pdf|access-date=18 January 2015|archive-date=12 April 2019|archive-url=https://web.archive.org/web/20190412025028/http://paulrittman.com/Indian%20Culture%20and%20the%20Horse.pdf}} Similarly, the brumby descended from horses strayed or let loose in Australia by English settlers.{{Cite journal | doi = 10.1071/WR06102 | last1 = Nimmo | first1 = D. G. | last2 = Miller | first2 = K. K. | year = 2007 | title = Ecological and human dimensions of management of feral horses in Australia: A review | url = http://pdfs.semanticscholar.org/8a57/bf826fec75c507e4f767a325b255734ceba7.pdf | archive-url = https://web.archive.org/web/20200705201934/http://pdfs.semanticscholar.org/8a57/bf826fec75c507e4f767a325b255734ceba7.pdf | archive-date = 2020-07-05 | journal = Wildlife Research | volume = 34 | issue = 5| pages = 408–417| bibcode = 2007WildR..34..408N | s2cid = 26285264 }} Isolated populations of feral horses occur in a number of places, including Bosnia, Croatia, New Zealand, Portugal, Scotland and a number of barrier islands along the Atlantic coast of North America from Sable Island off Nova Scotia, to Cumberland Island, off the coast of Georgia.{{cite web|title = Wildlife|url = http://cumberlandisland.com/the-island/wildlife/|website = Cumberland Island|access-date = 2015-11-20}} Even though these are often referred to as "wild" horses, they are not truly "wild" if wildness is defined as having no domesticated ancestors.

In 1995, British and French explorers encountered 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.{{Cite news|url=https://www.nytimes.com/1995/11/12/world/a-stone-age-horse-still-roams-a-tibetan-plateau.html|title=A Stone-Age Horse Still Roams a Tibetan Plateau|last=Simons|first=Marlise|date=1995-11-12|work=The New York Times|issn=0362-4331}} It was speculated that the Riwoche horse might be a relict population of wild horses,{{cite encyclopedia |author=Dohner, Janet Vorwald |editor= Dohner, Janet Vorwald |title=Equines: Natural History |encyclopedia=Historic and Endangered Livestock and Poultry Breeds |year=2001 |publisher=Yale University Press |location=Topeka, KS |pages=400–401 | isbn = 978-0-300-08880-9}} but testing did not reveal genetic differences with domesticated horses,{{cite book|title=Tibet: the secret continent|author=Peissel, Michel|year=2002|publisher=Macmillan|isbn=978-0-312-30953-4|page=36|url=https://books.google.com/books?id=6sFWvuBug8IC&q=riwoche%20horse&pg=PA36}} which is in line with news reports indicating that they are used as pack and riding animals by the local villagers.{{cite web|title=Tibetan discovery is 'horse of a different color'|publisher=CNN|date=17 November 1995|access-date=2009-09-09|url=http://www-cgi.cnn.com/WORLD/9511/tibet_pony/index.html|author=Humi, Peter|archive-date=3 December 2014|archive-url=https://web.archive.org/web/20141203233407/http://www-cgi.cnn.com/WORLD/9511/tibet_pony/index.html}} These horses only stand {{hands|12}} tall and are said to resemble the images known as "horse no 2" depicted in cave paintings alongside images of Przewalski's horse.

Archaic humans hunted horses hundreds of thousands of years before the dispersal of modern humans across Eurasia during the Last Glacial Period. Examples of sites demonstrating horse butchery by archaic humans include the Boxgrove site in southern England dating to around 500,000 years ago, where horse bones with cut marks (with a horse scapula possibly exhibiting a spear wound{{Cite journal |last=McNabb |first=John |date=June 2000 |title=Boxgrove |url=https://www.cambridge.org/core/product/identifier/S0003598X00059548/type/journal_article |journal=Antiquity |language=en |volume=74 |issue=284 |pages=439–441 |doi=10.1017/S0003598X00059548 |issn=0003-598X|url-access=subscription }}) are associated with Acheulean stone tools made by Homo heidelbergensis,{{Cite journal |last1=Bello |first1=Silvia M. |last2=Parfitt |first2=Simon A. |last3=Stringer |first3=Chris |date=September 2009 |title=Quantitative micromorphological analyses of cut marks produced by ancient and modern handaxes |url=https://linkinghub.elsevier.com/retrieve/pii/S0305440309001368 |journal=Journal of Archaeological Science |volume=36 |issue=9 |pages=1869–1880 |bibcode=2009JArSc..36.1869B |doi=10.1016/j.jas.2009.04.014|url-access=subscription }}{{Cite journal |last=Smith |first=Geoff M. |date=October 2013 |title=Taphonomic resolution and hominin subsistence behaviour in the Lower Palaeolithic: differing data scales and interpretive frameworks at Boxgrove and Swanscombe (UK) |url=https://linkinghub.elsevier.com/retrieve/pii/S0305440313001635 |journal=Journal of Archaeological Science |language=en |volume=40 |issue=10 |pages=3754–3767 |bibcode=2013JArSc..40.3754S |doi=10.1016/j.jas.2013.05.002|url-access=subscription }} the Schöningen site in Germany (also thought to have been created by Homo heidelbergensis) dating to around 300,000 years ago, where butchered horses are associated with wooden spears (the Schöningen spears, amongst the oldest known wooden spears),{{Cite journal |last1=Schoch |first1=Werner H. |last2=Bigga |first2=Gerlinde |last3=Böhner |first3=Utz |last4=Richter |first4=Pascale |last5=Terberger |first5=Thomas |display-authors=3 |date=December 2015 |title=New insights on the wooden weapons from the Paleolithic site of Schöningen |url=https://linkinghub.elsevier.com/retrieve/pii/S0047248415002080 |journal=Journal of Human Evolution |language=en |volume=89 |pages=214–225 |doi=10.1016/j.jhevol.2015.08.004 |pmid=26442632|bibcode=2015JHumE..89..214S |url-access=subscription }}{{Cite journal |last1=Urban |first1=Brigitte |last2=Krahn |first2=Kim J. |last3=Kasper |first3=Thomas |last4=García-Moreno |first4=Alejandro |last5=Hutson |first5=Jarod M. |last6=Villaluenga |first6=Aritza |last7=Turner |first7=Elaine |last8=Gaudzinski-Windheuser |first8=Sabine |last9=Farghaly |first9=Dalia |last10=Tucci |first10=Mario |last11=Schwalb |first11=Antje |display-authors=3 |date=July 2023 |title=Spatial interpretation of high-resolution environmental proxy data of the Middle Pleistocene Palaeolithic faunal kill site Schöningen 13 II-4, Germany |journal=Boreas |language=en |volume=52 |issue=3 |pages=440–458 |doi=10.1111/bor.12619 |issn=0300-9483 |doi-access=free|bibcode=2023Borea..52..440U |hdl=10810/68324 |hdl-access=free }} as well as the Lingjing site in Henan, China dating to 125–90,000 years ago.{{Cite journal |last1=Li |first1=Hao |last2=Li |first2=Zhan-yang |last3=Lotter |first3=Matt G. |last4=Kuman |first4=Kathleen |date=August 2018 |title=Formation processes at the early Late Pleistocene archaic human site of Lingjing, China |url=https://linkinghub.elsevier.com/retrieve/pii/S0305440318302243 |journal=Journal of Archaeological Science |language=en |volume=96 |pages=73–84 |doi=10.1016/j.jas.2018.05.004|bibcode=2018JArSc..96...73L |hdl=2263/65160 |hdl-access=free }} During the Upper Palaeolithic, there is evidence for the hunting of horses by modern humans in Europe,{{Cite journal |last1=Hoffecker |first1=John F. |last2=Holliday |first2=Vance T. |last3=Stepanchuk |first3=V.N. |last4=Lisitsyn |first4=S.N. |date=October 2018 |title=The hunting of horse and the problem of the Aurignacian on the central plain of Eastern Europe |url=https://linkinghub.elsevier.com/retrieve/pii/S1040618217312296 |journal=Quaternary International |language=en |volume=492 |pages=53–63 |doi=10.1016/j.quaint.2018.05.044|bibcode=2018QuInt.492...53H |url-access=subscription }} as well as Asia.S.A. Vasil’ev. (2003). [https://natuurtijdschriften.nl/pub/538700 Faunal exploitation, subsistence practices and Pleistocene extinctions in Paleolithic Siberia]. Deinsea, 9(1), 513–556. Early Paleoindians in North America hunted the continent's native horses shortly prior to their extinction.{{Cite journal |last1=Waters |first1=Michael R. |last2=Stafford |first2=Thomas W. |last3=Kooyman |first3=Brian |last4=Hills |first4=L. V. |date=2015-04-07 |title=Late Pleistocene horse and camel hunting at the southern margin of the ice-free corridor: Reassessing the age of Wally's Beach, Canada |journal=Proceedings of the National Academy of Sciences |language=en |volume=112 |issue=14 |pages=4263–4267 |doi=10.1073/pnas.1420650112 |doi-access=free |issn=0027-8424 |pmc=4394292 |pmid=25831543|bibcode=2015PNAS..112.4263W }} During the 3rd millennium BC, horses were domesticated on the western Eurasian steppes, with domestic horses spreading across Eurasia around 2000 BC.{{Cite journal |last1=Librado |first1=Pablo |last2=Khan |first2=Naveed |last3=Fages |first3=Antoine |last4=Kusliy |first4=Mariya A. |last5=Suchan |first5=Tomasz |last6=Tonasso-Calvière |first6=Laure |last7=Schiavinato |first7=Stéphanie |last8=Alioglu |first8=Duha |last9=Fromentier |first9=Aurore |last10=Perdereau |first10=Aude |last11=Aury |first11=Jean-Marc |last12=Gaunitz |first12=Charleen |last13=Chauvey |first13=Lorelei |last14=Seguin-Orlando |first14=Andaine |last15=Der Sarkissian |first15=Clio |display-authors=3 |date=2021-10-28 |title=The origins and spread of domestic horses from the Western Eurasian steppes |journal=Nature |language=en |volume=598 |issue=7882 |pages=634–640 |doi=10.1038/s41586-021-04018-9 |issn=0028-0836 |pmc=8550961 |pmid=34671162|bibcode=2021Natur.598..634L }}

• Horse behavior
• Domestication of the horse

{{Reflist}}

{{refbegin}}

• {{cite iucn |author=King, S.R.B. |author2=Boyd, L. |author3=Zimmermann, W. |author4=Kendall, B.E. |year=2015 |errata=2016 |title=Equus ferus |volume=2015 |page=e.T41763A97204950 |doi=10.2305/IUCN.UK.2015-2.RLTS.T41763A45172856.en |access-date=6 July 2024}}
• Moelman, P.D. 2002. Equids. Zebras, Asses and Horses. Status Survey and Conservation Action Plan. IUCN/SSC Equid Specialist Group. IUCN, Gland, Switzerland.
• {{cite book | author = Ronald M. Nowak | title = Walker's Mammals of the World | isbn = 0-8018-5789-9 | year = 1999 | publisher = Johns Hopkins University Press | location = Baltimore | edition = 6th | lccn = 98023686 | language = en }}

{{refend}}

{{Horse topics}}

{{Equus|state=collapsed}}

{{Perissodactyla}}

{{Taxonbar|from=Q27742}}

{{Authority control}}

{{DEFAULTSORT:Wild Horse}}

Category:Equus (genus)

Category:Mammals described in 1785

Category:Types of horse