Editing Przewalski's horse

{{Short description|Subspecies of mammal}}
{{Use dmy dates|date=August 2019}}
{{Subspeciesbox
| image = Przewalskis horse 02.jpg
| image_caption = 
| status = EN
| status_system = IUCN3.1
| status_ref = <ref name=IUCN/>
| status2 = CITES_A1
| status2_system = CITES
| status2_ref = <ref>{{Cite web|title=Appendices {{!}} CITES|url=https://cites.org/eng/app/appendices.php|access-date=2022-01-14|website=cites.org|archive-date=3 February 2007|archive-url=https://web.archive.org/web/20070203100154/http://www.cites.org/eng/app/appendices.shtml|url-status=live}}</ref>
| genus = Equus
| species = ferus
| species_link = Wild horse
| subspecies = przewalskii
| authority = (I.&nbsp;S.&nbsp;Polyakov, 1881)
| range_map = {{maplink|frame=yes|frame-align=center|frame-width=200|plain=yes|from=Przewalski's horse range.map}}
| range_map_caption = Przewalski's horse range<br />([[IUCN]] distribution of Przewalski's horse, where it is extant & reintroduced to 5 disjointed areas in Northern China and Southern Mongolia; missing distribution in Russia, Belarus, and Ukraine)
| synonyms = * Species Level:
** ''Equus przewalskii'' <small>Polyakov, 1881</small>
* Subspecies Level:
**''E. f. hagenbecki'' <small>[[Paul Matschie|Matschie]], 1903</small>
**''E. f. prjevalskii'' <small>[[James Cossar Ewart|Ewart]], 1903</small>
**''E. f. typicus'' <small>[[Max Hilzheimer]], 1909</small>
}}

'''Przewalski's horse'''{{efn|British English: {{IPAc-en|ˌ|p|ɜːr|ʒ|ə|ˈ|v|æ|l|s|k|i}} {{respell|PUR|zhə|VAL|skee}},<ref>{{Cite encyclopedia |url=http://www.lexico.com/definition/Przewalski%27s+horse |title=Przewalski's horse |dictionary=[[Lexico]] UK English Dictionary |publisher=[[Oxford University Press]]}}{{dead link|date=September 2022|bot=medic}}{{cbignore|bot=medic}}</ref> American English: {{IPAc-en|-|ˈ|v|ɑː|l|-}} {{respell|-|VAHL|-}},<ref>{{Cite Merriam-Webster |Przewalski's horse |access-date=2023-04-29 }}</ref> {{IPA|pl|pʂɛˈvalskʲi|lang|small=no|link=yes}}, {{IPA|ru|prʐɨˈvalʲskʲɪj|lang|small=no|link=yes}} ({{lang|ru|Пржевальский}}).}} ('''''Equus ferus przewalskii''''' or '''''Equus przewalskii'''''),<ref name="STWH" /> also called the '''takhi''',{{efn|{{langx|mn|Тахь}}.}}<ref name="ITG">{{cite web|url=http://www.takhi.org/en/|title=Takhi: Holy Animal of Mongolia|publisher=International Takhi Group|access-date=13 August 2016|archive-date=5 August 2016|archive-url=https://web.archive.org/web/20160805010851/http://www.takhi.org/en/|url-status=live}}</ref> '''Mongolian wild horse''' or '''Dzungarian horse''', is a rare and endangered [[horse]] originally native to the [[steppe]]s of [[Central Asia]]. It is named after the Russian geographer and explorer [[Nikolay Przhevalsky]]. Once [[extinct in the wild]], since the 1990s it has been [[Reintroduction|reintroduced]] to its native habitat in Mongolia in the [[Khustain Nuruu National Park]], Takhin Tal Nature Reserve, and Khomiin Tal, as well as several other locales in Central Asia and [[Eastern Europe]].<ref name=IUCN/>

Several genetic characteristics of Przewalski's horse differ from what is seen in modern domestic horses, indicating neither is an ancestor of the other. For example,  Przewalski's horse has 33 chromosome pairs, compared to 32 for the domestic horse.  Their ancestral lineages split from a common ancestor between 160,000 and 38,000 years ago, long before the [[domestication of the horse]]. Przewalski's horse was long considered the only remaining truly wild horse, in contrast with the American [[mustang]] and the Australian [[brumby]], which are instead [[feral horse]]s descended from [[domesticated]] animals. That status was called into question when domestic horses of the 5,000-year-old [[Botai culture]] of Central Asia were found to be more closely related to Przewalski's horses than to ''E. f. caballus''. The study raised the possibility that modern Przewalski's horses could be the feral descendants of the domestic Botai horses. However, it remains possible that both the Botai horses and the modern Przewalski's horses descend separately from the same ancient wild Przewalski's horse population. Its [[Taxonomy (biology)|taxonomic]] position is still debated, with some taxonomists treating Przewalski's horse as a [[species]], ''E.&nbsp;przewalskii'', others as a [[subspecies]] of [[wild horse]] (''E.&nbsp;ferus przewalskii'') or a variety of the domesticated horse (''E. caballus'').

Przewalski's horse is stockily built, smaller, and shorter than its domesticated relatives. Typical height is about {{hands|12|-|14}}, and the average weight is around {{convert|300|kg|lb|abbr=on}}. They have a [[Dun gene|dun]] coat with ''[[pangaré]]'' features and often have dark [[primitive markings]].

==Taxonomy==
Przewalski's horse was formally described as a novel species in 1881 by [[:ru:Поляков, Иван Семёнович|Ivan Semyonovich Polyakov]]. The taxonomic position of Przewalski's horse remains controversial, and no consensus exists about whether it is a full species (as ''Equus przewalskii''); a subspecies of ''Equus ferus'' the [[wild horse]] (as ''Equus ferus przewalskii'' in [[trinomial nomenclature]], along with two other subspecies, the [[Horse|domestic horse]] ''E.&nbsp;f.&nbsp;caballus'', and the extinct [[tarpan]] ''E.&nbsp;f.&nbsp;ferus''); or even a subpopulation of the domestic horse.<ref name="lau 2009 199–208"/><ref name=kavar08/><ref name=ChinaancientDNA/> The [[American Society of Mammalogists]] considers Przewalski's horse and the tarpan both to be subspecies of ''Equus ferus'', and classifies the domestic horse as a separate species, ''Equus caballus''.<ref>{{Cite web|title=Explore the Database|url=https://www.mammaldiversity.org/explore.html#species-id=1006123|access-date=2021-08-20|website=www.mammaldiversity.org|archive-date=28 October 2020|archive-url=https://web.archive.org/web/20201028140029/https://www.mammaldiversity.org/explore.html#species-id=1006123|url-status=live}}</ref>

==Lineage==
Genetic analysis shows that the takhi and the domestic horse differ significantly, with neither ancestral to the other. The evolutionary [[Genetic divergence|divergence]] of the two populations was estimated to have occurred about 72,000–38,000 years ago, well before domestication, most likely due to climate, topography, or other environmental changes.<ref>{{cite journal |last1=Orlando |first1=L. |last2=Ginolhac |first2=A.L. |last3=Zhang |first3=G. |last4=Froese |first4=D. |last5=Albrechtsen |first5=A. |last6=Stiller |first6=M. |last7=Schubert |first7=M. |last8=Cappellini |first8=E. |last9=Petersen |first9=B. |last10=Moltke |first10=I. |last11=Johnson |first11=P.L.F. |last12=Fumagalli |first12=M. |last13=Vilstrup |first13=J.T. |last14=Raghavan |first14=M. |last15=Korneliussen |first15=T. |last16=Malaspinas |first16=A.S. |last17=Vogt |first17=J. |last18=Szklarczyk |first18=D. |last19=Kelstrup |first19=C.D. |last20=Vinther |first20=J. |last21=Dolocan |first21=A. |last22=Stenderup |first22=J. |last23=Velazquez |first23=A.M.V. |last24=Cahill |first24=J. |last25=Rasmussen |first25=M. |last26=Wang |first26=X. |last27=Min |first27=J. |last28=Zazula |first28=G.D. |last29=Seguin-Orlando |first29=A. |last30=Mortensen |first30=C. |display-authors=6 |year=2013 |title=Recalibrating Equus evolution using the genome sequence of an early Middle Pleistocene horse |doi=10.1038/nature12323 |journal=Nature |volume=499 |issue=7456 |pages=74–78 |pmid=23803765 |bibcode=2013Natur.499...74O |s2cid=4318227}}</ref><ref>{{cite journal |last1=Sarkissian |first1=C. |last2=Ermini |first2=L. |last3=Schubert |first3=M. |last4=Yang |first4=M.A. |last5=Librado |first5=P. |display-authors=etal |year=2015 |title=Evolutionary genomics and conservation of the endangered Przewalski's horse |doi=10.1016/j.cub.2015.08.032 |pmid=26412128 |journal=Curr. Biol. |volume=25 |issue=19 |pages=2577–83 |pmc=5104162|bibcode=2015CBio...25.2577D }}</ref><ref name=machugh2016>{{cite journal |doi=10.1146/annurev-animal-022516-022747 |title=Taming the past: Ancient DNA and the study of animal domestication |journal=Annual Review of Animal Biosciences |volume=5 |year=2016 |last1=Machugh |first1=David E. |last2=Larson |first2=Greger |last3=Orlando |first3=Ludovic |pmid=27813680 |pages=329–351|s2cid=21991146 }}</ref>

According to a 2009 study, the earliest known domestic horses were found at settlements of the Botai culture, from about 5500 years ago. These horses were raised for meat and milk.<ref>{{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=etal |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 }}</ref> In 2018, a new study indicated ancient horses of the Botai culture are related to takhis, not to domestic horses as was previously thought. Specifically, the Botai horses appeared to be ancestral to the modern takhi, because all seven takhis nested within the [[phylogenetic tree]] of the 20 Botai horses. No comparison was made to definitively wild early takhis. The authors posit that modern Przewalski's horses are [[Feral animal|feral]] descendants of the ancient Botai domesticated animals, rather than representing a surviving population of never-domesticated horses.<ref name="sciencemag.org">{{cite web |author=Pennisi, Elizabeth |author-link=Elizabeth Pennisi |title=Ancient DNA upends the horse family tree |website=sciencemag.org |date=22 February 2018 |url=https://www.science.org/content/article/ancient-dna-upends-horse-family-tree |access-date=30 June 2022 |archive-date=21 September 2022 |archive-url=https://web.archive.org/web/20220921222121/https://www.science.org/content/article/ancient-dna-upends-horse-family-tree |url-status=live }}</ref><ref name=Orlando2018>{{Cite journal |last1=Orlando |first1=Ludovic |last2=Outram |first2=Alan K. |last3=Librado| first3=Pablo |last4=Willerslev |first4=Eske |last5=Zaibert |first5=Viktor |last6=Merz |first6=Ilja |last7=Merz |first7=Victor |last8=Wallner |first8=Barbara |last9=Ludwig |first9=Arne |date=2018-04-06 |df=dmy-all |title=Ancient genomes revisit the ancestry of domestic and Przewalski's horses |journal=Science |language=en |volume=360 |issue=6384 |pages=111–114 |doi=10.1126/science.aao3297 |issn=0036-8075 |pmid=29472442|bibcode=2018Sci...360..111G |doi-access=free|hdl=10871/31710 |hdl-access=free }}</ref> Another geneticist pointed out that Przewalski's horses may have simply descended from the same wild population that the Botai horses came from, which would still be compatible with the findings of the study.<ref name="ArsTechnica">{{cite web|url=https://arstechnica.com/science/2018/02/ancient-dna-rules-out-archeologists-best-bet-for-horse-domestication/|date=February 25, 2018|title=Ancient DNA rules out archeologists' best bet for horse domestication|publisher=[[ArsTechnica]]|access-date=24 June 2020|archive-date=25 June 2020|archive-url=https://web.archive.org/web/20200625064751/https://arstechnica.com/science/2018/02/ancient-dna-rules-out-archeologists-best-bet-for-horse-domestication/|url-status=live}}</ref>

In 2021, William Taylor and Christina Barron-Ortiz disputed the evidence for domestication of Przewalski's horse.<ref name="Taylor et al. 2021">{{cite journal|last1=Taylor |first1=William Timothy Treal |last2=Barrón‑Ortiz |first2=Christina Isabelle |title=Rethinking the evidence for early horse domestication at Botai |journal=Scientific Reports |volume=11 |year=2021 |issue=1 |page=7440 |doi=10.1038/s41598-021-86832-9|pmid=33811228 |pmc=8018961 |bibcode=2021NatSR..11.7440T }}</ref> Their case was rejected by Alan Outram and colleagues in a paper which was not dated or peer-reviewed.<ref>{{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|archive-date=5 May 2024|archive-url=https://web.archive.org/web/20240505123450/https://ore.exeter.ac.uk/repository/bitstream/handle/10871/126599/Outram%20et%20al%20Rebuttal%20of%20Taylor.pdf?sequence=1|url-status=live}}</ref> Taylor reiterated his arguments that Przewalski's horse had never been domesticated in an article in ''[[Scientific American]]'' in 2024.<ref>{{cite journal| last=Taylor |first=William T. | journal=Scientific American |title=When Horse became Steed|volume=331 |number=5  |date=December 2024 |pages=24–30 |doi=10.1038/scientificamerican122024-7qfHkaSxwWOJpTcwY2J0bg |bibcode=2024SciAm.331e..22T |issn= }}</ref>

In any case, the Botai horses were found to have negligible genetic contribution to any of the ancient or modern domestic horses studied, indicating that the domestication of the latter was independent, involving a different wild population, from any possible domestication of Przewalski's horse by the Botai culture.<ref name="sciencemag.org"/><ref name=Orlando2018/><ref name="ArsTechnica"/>

==Characteristics==
[[File:Portrait of Przewalski's Horse.jpg|thumb|upright|Head shot, showing convex profile]]
Przewalski's horse is stockily built in comparison to domesticated horses, with shorter legs, and is much smaller and shorter than its domesticated relatives. Typical height is about {{hands|12|-|14}}, and length is about {{convert|2.1|m|abbr=on}}. It weighs around {{convert|300|kg|lb}}. The coat is generally [[Dun gene|dun]] in color with ''[[pangaré]]'' features, varying from dark brown around the mane, to pale brown on the flanks, and yellowish-white on the belly, as well as around the muzzle. The legs of Przewalski's horse are often faintly striped, also typical of [[primitive markings]].<ref>{{cite web |url=https://nationalzoo.si.edu/animals/przewalskis-horse |title=Przewalski's horse |website=Smithsonian's National Zoo |date=25 April 2016 |access-date=2019-04-26 |df=dmy-all}}</ref> The mane stands erect and does not extend as far forward,<ref name=Nature /> while the tail is about {{convert|90|cm|0|abbr=on}} long, with a longer [[rump (animal)|dock]] and shorter hair than seen in domesticated horses. The hooves of Przewalski's horse are longer in the front and have significantly thicker sole horns than feral horses, an adaptation that improves hoof performance on terrain.<ref>Patan-Zugaj, B., Hermann, C., & Budras, K.-D. (2013). History of the Przewalski horse (Equus Przewalskii) and morphological examination of seasonal changes of the hoof in Przewalski and feral horses. Retrieved from http://www.pferdeheilkunde.de/10.21836/PEM20130302.</ref>

===Genomics===
The [[karyotype]] of Przewalski's horse differs from that of the domestic horse, having 33&nbsp;chromosome pairs versus&nbsp;32, apparently due to a [[Fission (biology)|fission]] of a large chromosome ancestral to domestic horse chromosome&nbsp;5 to produce Przewalski's horse chromosomes&nbsp;23 and 24,<ref name=Piras>{{cite journal |last1=Piras |first1=F.M. |last2=Nergadze |first2=S.G. |last3=Poletto |first3=V. |last4=Cerutti |first4=F. |last5=Ryder |first5=O.A. |last6=Leeb |first6=T. |last7=Raimondi |first7=E. |last8=Giulotto |first8=E. |title=Phylogeny of Horse Chromosome 5q in the Genus Equus and Centromere Repositioning |journal=Cytogenetic and Genome Research |year=2009 |volume=126 |issue=1–2 |pages=165–172 |doi=10.1159/000245916 |pmid=20016166 |s2cid=24884868 |url=https://boris.unibe.ch/38295/ |archive-date=29 October 2023 |access-date=17 September 2023 |archive-url=https://web.archive.org/web/20231029195550/https://boris.unibe.ch/38295/ |url-status=live }}</ref> though conversely, a [[Robertsonian translocation]] that fused two chromosomes ancestral to those seen in Przewalski's horse to produce the single large domestic horse chromosome has also been proposed.<ref name=Huang>{{cite journal |last1=Huang |first1=Jinlong |last2=Zhao |first2=Yiping |last3=Shiraigol |first3=Wunierfu |last4=Li |first4=Bei |last5=Bai |first5=Dongyi |last6=Ye |first6=Weixing |last7=Daidiikhuu |first7=Dorjsuren |last8=Yang |first8=Lihua |last9=Jin |first9=Burenqiqige |last10=Zhao |first10=Qinan |last11=Gao |first11=Yahan |last12=Wu |first12=Jing |last13=Bao |first13=Wuyundalai |last14=Li |first14 = Anaer |last15=Zhang |first15=Yuhong |last16=Han |first16=Haige |last17=Bai |first17=Haitang |last18=Bao |first18=Yanqing |last19=Zhao |first19=Lele |last20=Zhai |first20=Zhengxiao |last21=Zhao |first21=Wenjing |last22=Sun |first22=Zikui |last23=Zhang |first23=Yan |last24=Meng |first24=He |last25=Dugarjaviin |first25=Manglai |display-authors=6 |year=2015 |title=Analysis of horse genomes provides insight into the diversification and adaptive evolution of karyotype |journal=Scientific Reports |volume=4 |page=4958 |pmid=24828444 |pmc=4021364 |doi=10.1038/srep04958 |url=}}</ref>

Many smaller [[Chromosomal inversion|inversions]], [[Insertion (genetics)|insertions]] and other rearrangements were observed between the chromosomes of domestic and Przewalski's horses, while there was much lower hetero[[zygosity]] in Przewalski's horses, with extensive segments devoid of genetic diversity, a consequence of the recent severe [[Population bottleneck|bottleneck]] of the captive Przewalski's horse population.<ref name=Huang/> In comparison, the chromosomal differences between domestic horses and [[zebra]]s include numerous large-scale [[Chromosomal translocation|translocations]], fusions, inversions, and [[centromere]] repositioning.<ref name=Piras/> Przewalski's horse has the highest [[diploid]] chromosome number among all equine species. They can interbreed with the domestic horse and produce fertile offspring, with 65&nbsp;chromosomes.<ref name="lau 2009 199–208"/>

The mitochondrial genome has 37 genes that are 99.63% identical to that of the domestic horse.<ref>{{cite journal |last1=Flack |first1=Nicole |last2=Hughes |first2=Lauren |last3=Cassens |first3=Jacob |last4=Enriquez |first4=Maya |last5=Gebeyehu |first5=Samrawit |last6=Alshagawi |first6=Mohammed |last7=Hatfield |first7=Jason |last8=Kauffman |first8=Anna |last9=Brown |first9=Baylor |last10=Klaeui |first10=Caitlin |last11=Mabrouk |first11=Islam F |last12=Walls |first12=Carrie |last13=Yeater |first13=Taylor |last14=Rivas |first14=Anne |last15=Faulk |first15=Christopher |title=The genome of Przewalski's horse ( Equus ferus przewalskii ) |journal=G3: Genes, Genomes, Genetics |date=28 May 2024 |volume=14 |issue=8 |pages=jkae113 |doi=10.1093/g3journal/jkae113|doi-access=free |pmid=38805182 |pmc=11304947 }}</ref>

==Ecology and behavior==
{{main|Horse behavior}}
[[File:Wintercoat.jpg|thumb|Winter coat]]
Przewalski reported the horses forming troops of between five and fifteen members, consisting of a mature stallion, his mares and foals.<ref name=Nature /> Modern reintroduced populations similarly form family groups of one adult stallion, one to three mares, and their common offspring that stay in the family group until they are no longer dependent, usually at two or three years old. Young females join other harems, while bachelor stallions as well as old stallions who have lost their harems join bachelor groups.<ref name=Kerekes>{{cite journal |first1=Viola |last1=Kerekes |first2=István |last2=Sándor |first3=Dorina |last3=Nagy |first4=Katalin |last4=Ozogány |first5=Loránd |last5=Göczi |first6=Benjamin |last6=Ibler |first7=Lajos |last7=Széles |first8=Zoltán |last8=Barta |title=Trends in demography, genetics, and social structure of Przewalski's horses in the Hortobagy National Park, Hungary over the last 22 years |journal=Global Ecology and Conservation |year=2021 |volume=25 |page=e01307 | doi=10.1016/j.gecco.2020.e01407|doi-access=free |bibcode=2021GEcoC..2501407K }}</ref>  Family groups can join to form a herd that moves together.{{citation needed|date=June 2020}}

The patterns of their daily lives exhibit [[horse behavior]] similar to that of [[feral horse]] herds. Stallions herd, drive, and defend all members of their family, while the mares often display leadership in the family. Stallions and mares stay with their preferred partners for years. While behavioral synchronization is high among mares, stallions other than the main harem stallion are generally less stable in this respect.{{citation needed|date=June 2020}}

Home range in the wild is little studied, but estimated as {{Cvt|1.2–24|km2|sqmi|sigfig=2}} in the Hustai National Park and {{Cvt|150-825|km2|sqmi}} in the [[Great Gobi B Strictly Protected Area]].<ref>{{cite web |title=Przewalski's Horse (Equus ferus) Fact Sheet: Behavior & Ecology |url=http://ielc.libguides.com/sdzg/factsheets/przewalskishorse/behavior |publisher=San Diego Zoo Global Library |via=IELC |access-date=29 April 2019 |archive-date=2 August 2019 |archive-url=https://web.archive.org/web/20190802000437/http://ielc.libguides.com/sdzg/factsheets/przewalskishorse/behavior |url-status=live }}</ref> The ranges of harems are separated, but slightly overlapping.<ref name=Kerekes /> They have few modern predators, but one of the few is the [[Himalayan wolf]].<ref>{{cite journal |last1=Balajeid Lyngdoh |first1=S. |last2=Habib |first2=B. |last3=Shrotriya |first3=S. |title=Dietary spectrum in Himalayan wolves: comparative analysis of prey choice in conspecifics across high-elevation rangelands of Asia |journal=Journal of Zoology |date=January 2020 |volume=310 |issue=1 |pages=24–33 |doi=10.1111/jzo.12724 |s2cid=202010931 |url=https://cdn.downtoearth.org.in/library/0.69048700_1565775720_dietary-spectrum-in-himalayan-wolves.pdf |access-date=1 March 2023 |archive-date=24 October 2020 |archive-url=https://web.archive.org/web/20201024183034/https://cdn.downtoearth.org.in/library/0.69048700_1565775720_dietary-spectrum-in-himalayan-wolves.pdf |url-status=live }}</ref>

Horses maintain visual contact with their family and herd at all times, and have a host of ways to communicate with one another, including vocalizations, [[scent marking]], and a wide range of visual and tactile signals. Each kick, groom, tilt of the ear, or other contact with another horse is a means of communicating. This constant communication leads to complex social behaviors among Przewalski's horses.<ref>{{cite book |author=Feh, C. |year=2005 |article=Relationships and communication in socially natural horse herds |title=The Domestic Horse: the evolution, development and management of its behaviour |editor1=Mills, Daniel |editor2=McDonnell, Sue |publisher=Cambridge University Press}}</ref>

The historical population was said to have lived in the "wildest parts of the desert" with a preference for "especially saline districts".<ref name=Nature /> They were observed mostly during spring and summer at natural wells, migrating to them by crossing valleys rather than by way of higher mountains.<ref name=boyd94 />

===Diet===
[[File:Equus przewalskii Le Villaret 02 2006-07-20.jpg|thumb|left|Przewalski's horses]]
Przewalski horse's diet consists of vegetation. Many plant species are in a typical Przewalski's horse environment, including: ''[[Elymus repens]]'', ''[[Carex]] ''spp., [[Fabaceae]], and [[Asteraceae]].<ref name="pol.j.ecol.cbe-pan.pl">{{cite journal |url=http://www.pol.j.ecol.cbe-pan.pl/article/ar59_4_19.pdf |title=Diet of the Przewalski's horse ''Equus przewalskii'' in the Chernobyl exclusion zone |archive-url=https://web.archive.org/web/20131029185432/http://www.pol.j.ecol.cbe-pan.pl/article/ar59_4_19.pdf |archive-date=29 October 2013 |author1=Kateryna Slivinska |author2=Grzegorz Kopij |journal=Polish Journal of Ecology |volume=59 |issue=4 |pages=841–847 |date=July 2011 |df=dmy-all}}</ref>
Looking at the species' diet overall, Przewalski's horses most often eat ''E.&nbsp;repens'', ''[[Trifolium pratense]]'', ''[[Vicia cracca]]'', ''[[Poa trivialis]]'', ''[[Dactylis glomerata]]'', and ''[[Bromus inermis]]''.<ref name="pol.j.ecol.cbe-pan.pl"/>

While the horses eat a variety of different plant species, they tend to favor different species at different times of year. In the springtime, they favor ''Elymus repens'', ''[[Corynephorus canescens]]'', ''[[Festuca valesiaca]],'' and ''[[Chenopodium album]]''. In early summer, they favor ''Dactylis glomerata'' and ''[[Trifolium]]'', and in late summer, they gravitate towards ''E.&nbsp;repens'' and ''Vicia cracca''.<ref name="pol.j.ecol.cbe-pan.pl"/>

In winter the horses eat ''[[Salix]] ''spp., ''[[Pyrus communis]]'', ''[[Malus]] sylvatica'', ''[[Pinus sylvestris]]'', ''[[Rose|Rosa]]'' spp., and ''[[Alnus]]'' spp. Additionally, Przewalski's horses may dig for ''[[Festuca]]'' spp., ''Bromus inermis'', and ''E.&nbsp;repens'' that grow beneath the ice and snow. Their winter diet is very similar to the winter diet of domestic horses,<ref name="pol.j.ecol.cbe-pan.pl"/> but differs from that revealed by isotope analysis of the historical (pre-captivity) population, which switched in winter to browsing shrubs, though the difference may be due to the extreme habitat pressure the historical population was under.<ref name=isotope/> In the wintertime, they eat their food more slowly than they do during other times of the year. Przewalski's horses seasonally display a set of changes collectively characteristic of physiologic adaptation to starvation, with their [[basal metabolic rate]] in winter being half what it is during springtime. This is not a direct consequence of decreased nutrient intake, but rather a programmed response to predictable seasonal dietary fluctuation.<ref>{{cite journal|last1=Arnold |first1=Walter |last2=Ruf  |first2=Thomas |last3=Kuntz |first3=Regina |title=Seasonal adjustment of energy budget in a large wild mammal, the Przewalski horse (Equus ferus przewalskii) II. Energy expenditure |journal=The Journal of Experimental Biology |volume=209 |pages=4566–4573 |year=2006 |issue=22 |doi=10.1242/jeb.02536|pmid=17079726 |s2cid=250512 |doi-access=free |bibcode=2006JExpB.209.4566A }}</ref>

===Reproduction===
Mating occurs in late spring or early summer. Mating stallions do not start looking for mating partners until the age of five. Stallions assemble groups of mares or challenge the leader of another group for dominance. Females are able to give birth at the age of three and have a gestation period of 11–12&nbsp;months. Foals are able to stand about an hour after birth.<ref name=ADW>{{cite web |last=Luu |first=J. |title=''Equus caballus przewalskii'' |url=http://animaldiversity.org/accounts/Equus_caballus_przewalskii/ |publisher=University of Michigan Museum of Zoology |website=Animal Diversity Web |access-date=29 April 2019 |archive-date=20 April 2019 |archive-url=https://web.archive.org/web/20190420173012/https://animaldiversity.org/accounts/Equus_caballus_przewalskii/ |url-status=live }}</ref> The rate of infant mortality among foals is 25%, with 83.3% of these deaths resulting from leading stallion [[Infanticide (zoology)|infanticide]].<ref name=Xinjiang/> Foals begin grazing within a few weeks but are not weaned for 8–13 months after birth.<ref name=ADW/> They reach sexual maturity at two years of age.<ref>{{cite web |title=Przewalski's Horse |url=https://www.aboutanimals.com/mammal/przewalskis-horse/ |website=aboutanimals |date=4 February 2016 |access-date=29 April 2019 |archive-date=20 April 2019 |archive-url=https://web.archive.org/web/20190420172947/https://www.aboutanimals.com/mammal/przewalskis-horse/ |url-status=live }}</ref>

==Population==
===History===
[[File:Anneau, M.C. 8756.jpg|thumb|upright|Przewalski's horse on bronze ring made in Northern [[Hebei]] and Western [[Liaoning]]. 6th-5th century BCE. [[Musée Cernuschi]]]]
Przewalski's-type wild horses appear in European cave art dating as far back as 20,000 years ago,<ref name=IUCN/> but genetic investigation of a 35,870-year-old specimen from one such cave instead showed an affinity with extinct Iberian horse lineage and the modern domestic horse, suggesting that it was not Przewalski's horse being depicted in this art.<ref>{{cite journal|first1=Antoine |last1=Fages |first2=Kristian |last2=Hanghøj |first3=Naveed |last3=Khan |display-authors=etal |title=Tracking Five Millennia of Horse Management with Extensive Ancient Genome Time Series |journal=Cell |year=2019 |volume=177 |issue=6 |pages=1419–1435 |doi=10.1016/j.cell.2019.03.049|pmid=31056281 |pmc=6547883 |doi-access=free }}</ref> Horse skeletons dating to the fifth to the third millennia BCE, found in Central Asia, with a range extending to the southern [[Ural Mountains|Urals]] and the [[Altai Mountains|Altai]], belong to the genetic lineage of Przewalski's horse.<ref>{{cite journal |last1=Librado |first1=Pablo |last2=Khan |first2=Naveed |last3=kusliy |first3=Mariya A.|display-authors=etal |title=The origins and spread of domestic horses from the Western Eurasian steppes |journal=Nature |year=2021 |volume=596 |issue=7882 |pages=634–640 |doi=10.1038/s41586-021-04018-9|pmid=34671162 |pmc=8550961 |bibcode=2021Natur.598..634L |s2cid=239050837 }}</ref> Of particular note are the horses of this lineage found in the archaeological sites of the [[Chalcolithic]] Botai culture. Sites dating from the mid-fourth-millennium BCE show evidence of horse domestication.<ref>{{cite journal|first1=Alan K |last1=Outram |first2=Natalie A |last2=Stear |first3=Robin |last3=Bendrey |first4=Sandra |last4=Olsen |first5=Alexei |last5=Kasparov |first6=Victor |last6=Zaibert |first7=Nick |last7=Thorpe |first8=Richard P |last8=Evershed |title=The Earliest Horse Harnessing and Milking |journal=Science |volume=323 |pages=1332–1335 |year=2009 |issue=5919 |doi=10.1126/science.1168594|pmid=19265018 |bibcode=2009Sci...323.1332O |s2cid=5126719 }}</ref> Analysis of ancient DNA from Botai horse specimens from about 3000 BCE reveals them to have DNA markers consistent with the lineage of modern Przewalski's horses.<ref name="sciencemag.org"/>

There are sporadic reports of Przewalski's horse in the historical record before its formal characterization. The Buddhist monk Bodowa wrote a description of what is thought to have been Przewalski's horse about AD 900,<ref name=isotope /> and an account from 1226 reports an incident involving wild horses during [[Genghis Khan]]'s campaign against the [[Western Xia|Tangut empire]].<ref name=IUCN/>  In the fifteenth century, [[Johann Schiltberger]] recorded one of the first European sightings of the horses in the journal recounting his trip to Mongolia as a prisoner of the [[Mongol]] [[Khan (title)|Khan]].<ref>{{cite web |url=http://afs.okstate.edu/breeds/horses/przewalski |series=Breeds of Livestock |title=Przewalski Horse |website=Breeds of Livestock, Department of Animal Science |publisher= Oklahoma State University |access-date=2019-04-29 |url-status=live |archive-url=https://web.archive.org/web/20141017090523/http://www.ansi.okstate.edu/breeds/horses/przewalski/index.htm |archive-date=17 October 2014 |df=dmy-all}}</ref> Another was recorded as a gift to the Manchurian emperor around 1630, its value as a gift suggesting a difficulty in obtaining them.<ref name=boyd94/> [[John Bell (traveller)|John Bell]], a Scottish doctor in service to [[Peter the Great]] from 1719 to 1722, observed a horse in Russia's [[Tomsk Oblast]] that was apparently this species,<ref name=isotope /> and a few decades later in 1750, a large hunt with thousands of beaters organized by the Manchurian emperor killed between two and three hundred of these horses.<ref name=boyd94/>
[[File:Przewalski horse skull 01.JPG|thumb|Przewalski's horse skull, Brno museum]]
The species is named after a Russian colonel of Polish descent, [[Nikolai Przhevalsky]] (1839–1888) (Nikołaj Przewalski in Polish). An explorer and naturalist, he obtained the skull and hide of an animal shot in 1878 in the Gobi near today's China–Mongolia border. He would travel to the Dzungarian Basin to observe it in the wild.<ref name=isotope /> In 1881, the horse received a formal scientific description and was named ''Equus przevalskii'' by Ivan Semyonovich Polyakov, based on Przewalski's collection and description,<ref name=isotope /><ref name=Nature /> while in 1884, the sole exemplar of the horse in Europe was a preserved specimen in the [[Zoological Museum of the Zoological Institute of the Russian Academy of Sciences|Museum of the Russian Academy of Sciences]] in [[St. Petersburg]].<ref name=Nature /> This was supplemented in 1894 when the brothers Grum-Grzhimailo returned several hides and skulls to St. Petersburg and described the horse's behavior in the wild.<ref name=boyd94/> A number of these horses were captured around 1900 by [[Carl Hagenbeck]] and placed in zoos, and these, along with one later captive, reproduced to give rise to today's population.

After 1903, there were no reports of the wild population until 1947, when several isolated groups were observed and a lone [[filly]] captured. Although local herdsmen reported seeing as many as 50 to 100 takhis grazing in small groups then, there were only sporadic sightings of single groups of two or three animals after that, mostly near natural wells.<ref name=boyd94/> Two scientific expeditions in 1955 and 1962 failed to find any. After herders and naturalists reported single harem groups in 1966 and 1967, the last observation of the wild horse in its native habitat was of a single stallion in 1969.<ref name=boyd94/><ref name=Fijn /> Expeditions after this failed to locate any horses, and the species would be designated "extinct in the wild" for over 30&nbsp;years.<ref name=boyd94/> Competition with livestock, hunting, capture of foals for zoological collections, military activities, and harsh winters recorded in 1945, 1948, and 1956 are considered to be main causes of the decline in Przewalski's horse population.<ref name=GBE2011 />

The wild population was already rare at its first scientific characterization. Przewalski reported seeing them only from a distance and may have instead sighted herds of local [[onager]] Mongolian wild asses. He was only able to obtain specimens of the type from Kirghiz hunters.<ref name=Fijn />  The range of Przewalski's horse was limited to the arid [[Gobi Desert#Dzungaria Basin semi-desert|Dzungarian Basin]] in the [[Gobi Desert]].<ref name=Nature>"Przevalsky's Wild Horse", ''Nature'', 30:391-392 (1884).</ref> It has been suggested that this was not their natural habitat, but, like the onager, they were a steppe animal driven to this barren last refuge by the dual pressures of hunting and habitat loss to agricultural grazing.<ref name=isotope>{{cite journal |first1=Petra |last1=Kaczensky |first2=Martina |last2=Burnik Šturm |first3=Mikhail V. |last3=Sablin |first4=Christian C. |last4=Voigt |first5=Steve |last5=Smith |first6=Oyunsaikhan |last6=Ganbaatar |first7=Boglarka |last7=Balint |first8=Chris |last8=Walzer |first9=Natalia N. |last9=Spasskaya |title=Stable isotopes reveal diet shift from pre-extinction to reintroduced Przewalski's horses |journal=Scientific Reports |volume=7 |page=5950 |year=2017 |issue=1 |doi=10.1038/s41598-017-05329-6|pmid=28729625 |pmc=5519547 |bibcode=2017NatSR...7.5950K }}</ref> There were two distinct populations recognized by local Mongolians, a lighter steppe variety and a darker mountain one. This distinction is seen in early twentieth-century descriptions. Their mountainous habitat included the ''Takhiin Shar Nuruu'' (The Yellow Wild-Horse Mountain Range).<ref name=Fijn>{{cite book |last=Fijn |first=Natasha |chapter=13. The domestic and the wild in the Mongolian horse and the takhi |title= Taxonomic Tapestries: The Threads of Evolutionary, Behavioural and Conservation Research |editor1-last=Behie |editor1-first=Alison M |editor2-last=Ozenham |editor2-first=Marc F |year=2015 |publisher=ANU Press, The Australian National University |location=Canberra |pages=279–298 |doi=10.22459/TT.05.2015.13 |doi-access=free }}</ref> In their last decades in the wild, the remnant population was limited to the small region between the Takhiin Shar Nuruu and Bajtag-Bogdo mountain ridges.<ref name=boyd94 />

===Captivity===
[[File:Equus ferus przewalskii 2.jpg|thumb|Vaska, a Przewalski horse trained to be ridden]]
Attempts to obtain specimens for exhibit and [[captive breeding]] were largely unsuccessful until 1902, when 28&nbsp;captured foals were brought to Europe. These and a small number of additional captives would be distributed among zoos and breeding centers in Europe and the United States. Many facilities failed in their attempts at captive breeding, but a few programs were established. However, by the mid-1930s, inbreeding had caused reduced fertility, and the captive population experienced a [[genetic bottleneck]], with the surviving captive breeding stock descended from only 11 of the founder captives.<ref name=boyd94/> In addition, in at least one instance, the progeny of interbreeding with a domestic horse was bred back into the captive Przewalski's horse population. However, recent studies have shown only minimal genetic contribution of this domestic horse to the captive population.<ref name=Bowling>{{cite journal |last1=Bowling |first1=Ann T. |last2=Ryder |first2=Oliver A. |title=Genetic studies of blood markers in Przewalski's horse |journal=The Journal of Heredity |volume=78 |issue=2 |pages=75–80 |year=1987 |url=http://cricket.biol.sc.edu/papers/horses/Genetic%20studies%20of%20blood%20markers%20in%20przewalski%27s%20horses.pdf |doi=10.1093/oxfordjournals.jhered.a110340 |pmid=3584938 |archive-date=18 May 2021 |access-date=21 April 2019 |archive-url=https://web.archive.org/web/20210518235306/http://cricket.biol.sc.edu/papers/horses/Genetic%20studies%20of%20blood%20markers%20in%20przewalski%27s%20horses.pdf |url-status=live }}</ref>

The situation was improved when the exchange of breeding animals among facilities increased genetic diversity and there was a consequent improvement in fertility, but the population experienced another genetic bottleneck when many of the horses failed to survive World War&nbsp;II. The most valuable group, in [[Askania Nova]], [[Ukraine]], was shot by German soldiers during [[World War&nbsp;II]] occupation, and the group in the United States had died out.<ref name=GBE2011 /> Only two captive populations in zoos remained, in [[Tierpark Hellabrunn|Munich]] and in [[Prague Zoo|Prague]], and of the 31&nbsp;remaining horses at war's end, only 9 became ancestors of the subsequent captive population.<ref name=boyd94/> By the end of the 1950s, only 12&nbsp;individual horses were left in the world's zoos.<ref name=GBE2011 />

A wild-caught mare captured as a foal a decade earlier was introduced into the Ukrainian captive population in 1957. This would prove the last wild-caught horse, and with the presumed extinction of the wild population, last sighted in Mongolia in the late 1960s, the captive population became the sole representatives of Przewalski's horse.<ref name=boyd94/>  Genetic diversity received a much-needed boost from this new source, with the spread of her bloodline through the inbred captive groups leading to their increased reproductive success, and by 1965, there were more than 130 animals spread among thirty-two zoos and parks.

===Conservation efforts===
[[File:Przewalski's Horse (02710137).jpg|thumb|Przewalski's horse in the Chernobyl Exclusion Zone]]

In 1977, the Foundation for the Preservation and Protection of the Przewalski Horse was founded in [[Rotterdam]], the Netherlands, by Jan and Inge Bouman. The foundation started a program of exchange between captive populations in zoos worldwide to reduce [[inbreeding]] and later began its own breeding program. As a result of such efforts, the extant herd has retained a far greater genetic diversity than its [[Population bottleneck|genetic bottleneck]] made likely.<ref name=GBE2011 />  By 1979, when this concerted program of population management to maximize [[genetic diversity]] was begun, there were almost four hundred horses in sixteen facilities,<ref name=boyd94/> a number that had grown by the early 1990s to over 1,500.<ref name=ZSL051219/>

While dozens of zoos worldwide have Przewalski's horses in small numbers, specialized reserves are also dedicated primarily to the species. The world's largest captive-breeding program for Przewalski's horses is at the [[Askania Nova]] preserve in Ukraine. From 1998, thirty-one horses were also released in the unenclosed [[Chernobyl Exclusion Zone]] in [[Ukraine]] and [[Belarus]]. People evacuated the zone after the [[Chernobyl accident]], so now it serves as a deserted ''[[de facto]]'' nature reserve.<ref name=bbc060420/> Though poaching has taken a toll on numbers,<ref>{{cite web |last=Gill |first=Victoria |date=27 July 2011 |title=Chernobyl's Przewalski's horses are poached for meat |url=http://www.bbc.co.uk/nature/14277058 |website=[[BBC|BBC Nature]] |access-date=2 May 2016 |df=dmy-all|archive-url=https://web.archive.org/web/20180427213925/http://www.bbc.co.uk/nature/14277058 |archive-date=27 April 2018}}</ref> as of 2019 the estimated population in the Chernobyl zone was over 100 individuals.<ref>{{Cite web|url=https://glavcom.ua/kyiv/news/u-chornobilskiy-zoni-prizhilisya-koni-przhevalskogo-foto-539517.html|title=У Чорнобильській зоні прижилися коні Пржевальського|date=26 October 2018|access-date=26 April 2020|archive-date=11 April 2021|archive-url=https://web.archive.org/web/20210411144702/https://glavcom.ua/kyiv/news/u-chornobilskiy-zoni-prizhilisya-koni-przhevalskogo-foto-539517.html|url-status=live}}</ref><ref>{{cite web | url=http://dazv.gov.ua/novini-ta-media/vsi-novyny/chornobilskij-zapovidnik-spilno-z-kijivskim-zooparkom-vivchayut-dikikh-konej-przhevalskogo-u-zoni-vidchuzhennya.html | title=Чорнобильський заповідник спільно з Київським зоопарком вивчають диких коней Пржевальського у зоні відчуження | access-date=3 September 2022 | archive-date=26 July 2019 | archive-url=https://web.archive.org/web/20190726144020/http://dazv.gov.ua/novini-ta-media/vsi-novyny/chornobilskij-zapovidnik-spilno-z-kijivskim-zooparkom-vivchayut-dikikh-konej-przhevalskogo-u-zoni-vidchuzhennya.html | url-status=bot: unknown }}</ref><ref>{{Cite news|url = https://www.bbc.com/ukrainian/news-52400959|title = У Чорнобилі знайшли обгоріле лоша. Тепер лікують у притулку|newspaper = BBC News Україна|archive-date = 7 November 2021|access-date = 26 April 2020|archive-url = https://web.archive.org/web/20211107151201/https://www.bbc.com/ukrainian/news-52400959|url-status = live}}</ref><ref>{{cite web|url=https://zora-irpin.info/zavezeni-z-mongoliyi-koni-przhevalskogo-prizhilisya-u-zoni-vidchuzhennya-chaes/|website=zora-irpin.info|title=Завезені з Монголії коні Пржевальського прижилися у зоні відчуження ЧАЕС|date=19 February 2020|language=uk}}</ref><ref name="ngWJ">{{cite web|last1=Wendle |first1=John |title=Animals Rule Chernobyl 30 Years After Nuclear Disaster |url=http://news.nationalgeographic.com/2016/04/060418-chernobyl-wildlife-thirty-year-anniversary-science/ |archive-url=https://web.archive.org/web/20160418224940/http://news.nationalgeographic.com/2016/04/060418-chernobyl-wildlife-thirty-year-anniversary-science/ |url-status=dead |archive-date=18 April 2016 |website=National Geographic |date=18 April 2016 |access-date=2 May 2016}}</ref>

Le Villaret, located in the Cevennes National Park in southern France and run by the Association Takh, is a breeding site for Przewalski's horses that was created to allow the free expression of natural Przewalski's horse behaviors. In 1993, eleven zoo-born horses were brought to Le Villaret. Horses born there are adapted to life in the wild, free to choose their mates, and required to forage independently. This was intended to produce individuals capable of being reintroduced into Mongolia. In 2012, 39 individuals were at Le Villaret.<ref name=takhleaflet/> An intensely researched population of free-ranging animals was also introduced to the [[Hortobágy National Park]] ''[[puszta]]'' in Hungary; data on social structure, behavior, and diseases gathered from these animals are used to improve the Mongolian conservation effort.<ref name=Kerekes /> An additional breeding population of Przewalski's horses roams the former Döberitzer Heide military [[proving ground]], now a nature reserve in [[Dallgow-Döberitz]], Germany. Established in 2008, this population comprised 24 horses in 2019.<ref>{{Cite web|date=2019-03-25|title=Die Przewalski-Pferde in der Döberitzer Heide|url=https://www.doris-semmelmann.de/die-przewalski-pferde-in-der-doeberitzer-heide-2627/|access-date=2021-01-18|language=de-DE|archive-date=24 January 2021|archive-url=https://web.archive.org/web/20210124155955/https://www.doris-semmelmann.de/die-przewalski-pferde-in-der-doeberitzer-heide-2627/|url-status=live}}</ref> Another population is being established in the [[Sistema Ibérico|Iberian System]] in Spain, the first free-roaming Przewalski’s horses in Western Europe.<ref>{{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}}</ref>

In 2024, a [[Colorado]] rancher discovered what appears to be a Przewalski's horse at a [[Kansas]] livestock auction,<ref>{{Cite news|date=2023-11-30|title='Ferrari in a junkyard': Mules sold at auction are rare, endangered horses|url=https://www.washingtonpost.com/climate-environment/2024/08/09/przewalskis-horses-rescued-dna-shrek-fiona/|access-date=2024-08-10|newspaper=Washington Post|language=en-US|archive-date=11 August 2024|archive-url=https://web.archive.org/web/20240811122911/https://www.washingtonpost.com/climate-environment/2024/08/09/przewalskis-horses-rescued-dna-shrek-fiona/|url-status=live}}</ref> mistakenly identified as a mule. Another similar horse was found at a [[Utah]] sanctuary. Genetic tests suggest both are Przewalski's horses, raising concerns about how they ended up in U.S. auctions.<ref name=":2">{{Cite web |url=https://www.nytimes.com/2024/10/23/nyregion/rare-horses-przewalski.html |title=How Two of the Rarest Horses on Earth Got Lost |work=The New York Times |date=23 October 2024 |access-date=23 October 2024 |archive-date=28 October 2024 |archive-url=https://web.archive.org/web/20241028014537/https://www.nytimes.com/2024/10/23/nyregion/rare-horses-przewalski.html/ |url-status=live |last1=Nir |first1=Sarah Maslin }}</ref> One horse, Fiona, was euthanized following apparent organ failure, while the other's fate is unreported.<ref name=":2" />

===Reintroduction===
[[File:Group of Takhi at Hustai.jpg|thumb|Przewalski's horses in Hustai Nuruu National Park]]
The Przewalski's Horse Reintroduction Project of China was initiated in 1985 when 11&nbsp;wild horses were imported from overseas. After more than two decades of effort, the [[Xinjiang]] Wild Horse Breeding Centre has bred a large number of horses, 55 of which were released into the [[Kalamely Mountain]] area. The animals quickly adapted to their new environment. In 1988, six foals were born and survived, and by 2001, over 100&nbsp;horses were at the centre. {{As of|2013}}, the center hosted 127 horses divided into 13&nbsp;breeding herds and three bachelor herds.{{cn|date=June 2024}} 

Reintroductions organized by Western European countries started in the 1990s. Several populations have now been released into the wild. A cooperative venture between the [[Zoological Society of London]] and Mongolian scientists has successfully reintroduced these horses from zoos into their natural habitat in Mongolia.  In 1992, 16 horses were released into the wild in Mongolia, followed by additional animals later. One of the areas to which they were reintroduced became [[Khustain Nuruu National Park]] in 1998. Another reintroduction site is [[Great Gobi&nbsp;B Strictly Protected Area]], located at the fringes of the [[Gobi Desert]].{{cn|date=June 2024}} 

In 2001, Przewalski's horses were reintroduced into the [[Kalamaili Nature Reserve]] in [[Xinjiang]], China.<ref name=Xinjiang>{{cite journal | last1=Chen | first1=Jinliang | last2=Weng | first2=Qiang | last3=Chao| first3=Jie | last4=Hu| first4=Defu | last5=Taya | first5=Kazuyoshi | title=Reproduction and Development of the Released Przewalski's Horses (''Equus przewalskii'') in Xinjiang, China | journal=Journal of Equine Science | volume=19 | issue=1 | pages=1–7 | year=2008 | doi=10.1294/jes.19.1 | pmid=24833949 | pmc=4019202}}</ref>  

Since 2004, there has been a program to reintroduce Przewalski's horses that were bred in France into Mongolia.<ref>{{cite web |url=https://news.nationalgeographic.com/2016/11/Claudia-Feh-explorer-moments-reintroducing-endangered-Przewalski-horses-into-the-wild/ |archive-url=https://web.archive.org/web/20161118125158/http://news.nationalgeographic.com/2016/11/Claudia-Feh-explorer-moments-reintroducing-endangered-Przewalski-horses-into-the-wild/ |url-status=dead |archive-date=18 November 2016 |title=A Wild Horse on the Comeback Trail |first=Gary |last=Strauss |work=National Geographic |date=2016-11-17 |access-date=2019-04-14 |df=dmy-all}}</ref> Instrumental to that 2004 reintroduction was [[Claudia Feh]], a Swiss equine specialist and conservation biologist, Feh led an effort to bring together animals that zoos had conserved to create a breeding population in southern France. Then, after it was established, three family groups were relocated to [[Khovd Province|Khovd]] in western Mongolia. At a site on the northern edge of the [[Gobi Desert]], Feh worked in cooperation with local people to ensure the horses survived and flourished. For this work, Feh received a [[Rolex Awards for Enterprise#2004|Rolex Award]] in 2004.<ref>{{cite web
	| url = https://www.rolex.org/rolex-awards/environment/claudia-feh
	| title = Claudia Feh: Wild Horses And Nomads
	| date = 2004
	| website = Rolex Awards
	| access-date = April 15, 2024
	| quote = Przewalski's horses had disappeared from the Mongolian steppes by the 1970s but Claudia Feh led one of several initiatives reintroducing them to the habitat they had ranged for centuries – and improved the lives of local nomads in the process.
	| archive-date = 3 March 2024
	| archive-url = https://web.archive.org/web/20240303054147/https://www.rolex.org/rolex-awards/environment/claudia-feh
	| url-status = live
	}}</ref>

In 2004 and 2005, 22&nbsp;horses were released by the Association Takh to a third reintroduction site in the buffer zone of the [[Khar Us Nuur National Park]], in the northern edge of the Gobi ecoregion. In the winter of 2009–2010, one of the worst ''[[dzud]]'' or snowy winter conditions ever hit Mongolia. The population of Przewalski's horse in the Great Gobi B SPA was drastically affected, providing clear evidence of the risks associated with reintroducing small and sequestered species in unpredictable and unfamiliar environments.{{citation needed|date=March 2021|reason=According to whom?}} 

After reintroduced horses had successfully reproduced, the status of the animal was changed from "extinct in the wild" to "[[endangered species |endangered]]" in 2005,<ref name=ZSL051219/> while on the [[IUCN Red List]] they were reclassified from "extinct in the wild" to "[[critically endangered]]", after a reassessment in 2008,<ref name=IUCN/> and from "critically endangered" to "endangered" after a 2011 reassessment.<ref name=IUCN2011/> 

In 2011, [[Prague Zoo]] started a new project, [[Return of the Wild Horses]]. With the support of public and many strategic partners, yearly transports of captive-bred horses into the [[Great Gobi B Strictly Protected Area]] continued.<ref>{{cite web |title=Return of the Przewalski's Horse to Mongolia |url=https://www.zoopraha.cz/en/animals/we-help-them-to-survive/projects/7678-return-of-the-przewalski-s-horse-to-mongolia |website=Zoo Praha |access-date=2019-06-27 |df=dmy-all |language=en}}</ref>  {{As of|2011|lc=y}}, an estimated total of almost 400&nbsp;horses existed in three free-ranging populations in the wild.<ref name=IUCN2011/> Prague Zoo has transported horses to Mongolia in several rounds in cooperation with partners (Czech Air Force, European Breeding Programme for Przewalski's Horses, Association pour le cheval de Przewalski: Takh, Czech Development Agency, Czech Embassy in Mongolia, and others). The zoo has the longest uninterrupted history of breeding Przewalski's horses in the world and keeps the studbook of this species.{{cn|date=June 2024}} 

The first reintroduction into the [[Orenburg Oblast|Orenburg]] region on the Russian steppe occurred in 2016.<ref>{{cite news| last=Blua | first=Antoine | title=Endangered Przewalski's Horses Back On Russian Steppe | date=13 March 2016 | access-date=17 December 2020 | publisher=RadioFreeEurope | url=https://www.rferl.org/a/endangered-horses-back-on-russian-steppe/27607786.html}}</ref><ref>{{cite journal | last1=Bakirova | first1=Rafilia T | last2=Sharkikh | first2=Tatjana | title=Programme on establishing a semi-free population of Przewalski's horse in Orenburg State Nature Reserve: the first successful project on the reintroduction of the species in Russia | journal=Nature Conservation Research | volume=4 | issue=Supplement 2 | pages=57–64  | year=2019| doi=10.24189/ncr.2019.025| doi-access=free | url=https://cyberleninka.ru/article/n/programme-on-establishing-a-semi-free-population-of-przewalski-s-horse-in-orenburg-state-nature-reserve-the-first-successful-project-on-the/pdf }}</ref> 

In May 2023, a herd of ten Przewalski's horses obtained from [[Monts D'Azur Biological Reserve]] in France was introduced by [[Rewilding Europe]] to the Iberian Highlands rewilding landscape in Spain, near [[Villanueva de Alcorón]]. Following an acclimatization period, the horses were released into the reserve proper in September. This introduction was intended to address the buildup of dense scrub caused by the decrease in traditional sheep grazing due to rural depopulation. The horses are intended to fill a niche similar to that of the extinct European wild horse and of contemporary domesticated [[herbivore]]s by opening the landscape through low-intensity grazing and browsing, thereby enhancing biodiversity and lowering the risk of [[forest fire]]s. Future introductions are planned.<ref>{{cite news | title=How an Iberian rewilding plan aims to repopulate 'empty Spain' | date=7 July 2023 | access-date=29 October 2023 | work=[[The Guardian]] | url=https://www.theguardian.com/world/2023/jul/07/iberian-rewilding-project-aims-repopulate-empty-spain | archive-date=4 August 2023 | archive-url=https://web.archive.org/web/20230804042614/https://www.theguardian.com/world/2023/jul/07/iberian-rewilding-project-aims-repopulate-empty-spain | url-status=live }}</ref><ref>{{cite news | title=Western Europe's first free-roaming herd of Przewalski's horses to enhance Iberian Highland rewilding | date=8 July 2023 | access-date=29 October 2023 | publisher=[[Rewilding Europe]] | url=https://rewildingeurope.com/news/western-europes-first-free-roaming-herd-of-przewalskis-horses-to-enhance-iberian-highland-rewilding/ | archive-date=10 July 2023 | archive-url=https://web.archive.org/web/20230710092015/https://rewildingeurope.com/news/western-europes-first-free-roaming-herd-of-przewalskis-horses-to-enhance-iberian-highland-rewilding/ | url-status=live }}</ref> 

In June 2024 six mares and a stallion were reintroduced to [[Kazakhstan]] from zoos in Europe,<ref name="Grdn2024">{{cite news |last1=Kevany |first1=Sophie |title=Wild horses return to Kazakhstan steppes after absence of two centuries |url=https://www.theguardian.com/environment/article/2024/jun/10/przewalskis-horses-only-wild-species-return-central-asian-steppes-kazakhstan |access-date=12 June 2024 |work=The Guardian |date=10 June 2024}}</ref> ten years after plans were announced to do so.<ref>{{cite news |last=Rutz |first=Julia |title=Effort Begins to Revive Endangered Przewalski Horse Population in Kazakhstan |date=11 November 2014 |access-date=18 December 2020 |publisher=Astana Times |url=https://astanatimes.com/2014/11/effort-begins-revive-endangered-przewalski-horse-population-kazakhstan/ |archive-date=14 May 2021 |archive-url=https://web.archive.org/web/20210514184846/https://astanatimes.com/2014/11/effort-begins-revive-endangered-przewalski-horse-population-kazakhstan/ |url-status=live }}</ref> The operation was organised by [[Prague Zoo]], which selected horses from various programs in Europe, which were housed at [[Tierpark Berlin]] for some months before being transported to Kazakhstan in Czech army planes.<ref>{{cite web | last=Mao | first=Frances | title=Przewalski's horses return to Kazakhstan steppes after 200 years | website=BBC News | date=13 June 2024 | url=https://www.bbc.com/news/articles/cljj0y15nnko | access-date=13 June 2024}}</ref>

===Assisted reproduction and cloning===
[[File:Przewalski 26-9-2004-3.jpg|thumb|right|Przewalski's horses]]
In the earlier decades of captivity, the insular breeding by individual zoos led to inbreeding and reduced fertility. In 1979, several American zoos began a collaborative breeding-exchange program to maximize genetic diversity.<ref name=BC8204/> Recent advances in equine reproductive science have also been used to preserve and expand the gene pool. Scientists at the [[Smithsonian Institution]]'s [[National Zoological Park (United States)|National Zoo]] successfully reversed a [[vasectomy]] on a Przewalski horse in 2007—the first operation of its kind on this species, and possibly the first ever on any endangered species. While normally, a vasectomy may be performed on an endangered animal under limited circumstances, particularly if an individual has already produced many offspring and its genes are overrepresented in the population, scientists realized the animal in question was one of the most genetically valuable Przewalski's horses in the North American breeding program.<ref name=AP080617/> The first birth by [[artificial insemination]] occurred on 27 July 2013 at the [[Smithsonian Conservation Biology Institute]].<ref name=PHAI/><ref>{{cite magazine |title=First Przewalski's Horse Born Via Artificial Insemination |date=5 August 2013 |url=http://news.nationalgeographic.com/news/2013/13/130805-przewalski-horse-born-artificial-insemination-animal-science/ |archive-url=https://web.archive.org/web/20130807120240/http://news.nationalgeographic.com/news/2013/13/130805-przewalski-horse-born-artificial-insemination-animal-science/ |url-status=dead |archive-date=7 August 2013 |magazine=National Geographic |access-date=14 August 2013 |last=Shenk |first=Emily |df=dmy-all}}</ref>

In 2020, the first cloned Przewalski's horse was born, the result of a collaboration between [[San Diego Zoo Global]], [[ViaGen Pets|ViaGen Equine]] and [[Revive & Restore]].<ref name=":0">{{Cite web|title=Przewalski's Horse (Takhi) Project {{!}} Revive & Restore|url=https://reviverestore.org/projects/przewalskis-horse/|access-date=2020-11-15|language=en-US|archive-date=8 September 2020|archive-url=https://web.archive.org/web/20200908050955/https://reviverestore.org/projects/przewalskis-horse/|url-status=live}}</ref> The [[cloning]] was carried out by [[somatic cell nuclear transfer]] (SCNT), whereby a viable [[embryo]] is created by transplanting the [[DNA]]-containing [[Cell nucleus|nucleus]] of a [[somatic cell]] into an immature egg cell ([[oocyte]]) that has had its nucleus removed, producing offspring genetically identical to the somatic cell donor.<ref>{{Cite journal|last1=Tian|first1=X. Cindy|last2=Kubota|first2=Chikara|last3=Enright|first3=Brian|last4=Yang|first4=Xiangzhong|date=2003-11-13|title=Cloning animals by somatic cell nuclear transfer – biological factors|url= |journal=Reproductive Biology and Endocrinology|volume=1|issue=1|pages=98|doi=10.1186/1477-7827-1-98|issn=1477-7827|pmc=521203|pmid=14614770 |doi-access=free }}</ref> Since the oocyte used was from a domestic horse, this was an example of interspecies SCNT.<ref>{{Cite journal|last1=Lagutina|first1=Irina|last2=Fulka|first2=Helena|last3=Lazzari|first3=Giovanna|last4=Galli|first4=Cesare|date=October 2013|title=Interspecies Somatic Cell Nuclear Transfer: Advancements and Problems|journal=Cellular Reprogramming|volume=15|issue=5|pages=374–384|doi=10.1089/cell.2013.0036|issn=2152-4971|pmc=3787369|pmid=24033141}}</ref>

The somatic cell donor was a Przewalski horse stallion named Kuporovic, born in the UK in 1975 and relocated three years later to the US, where he died in 1998. Due to concerns over the loss of [[genetic variation]] in the captive Przewalski's horse population, and in anticipation of the development of new cloning techniques, tissue from the stallion was [[cryopreserved]] at the San Diego Zoo's [[Frozen zoo|Frozen Zoo]]. Breeding of this individual in the 1980s had already substantially increased the genetic diversity of the captive population after he was discovered to have more unique [[allele]]s than any other horse living at the time, including otherwise lost genetic material from two of the original captive founders.<ref name=":0" /> To produce the clone, frozen skin [[fibroblast]]s were thawed, and grown in [[cell culture]].<ref name=":1">{{Cite web|title=About Cloning {{!}} Revive & Restore|url=https://reviverestore.org/projects/przewalskis-horse/about-cloning/|access-date=2020-11-15|language=en-US|archive-date=30 November 2020|archive-url=https://web.archive.org/web/20201130143403/https://reviverestore.org/projects/przewalskis-horse/about-cloning/|url-status=live}}</ref> An oocyte was collected from a domestic horse, and its nucleus replaced by a nucleus collected from a cultured Przewalski's horse fibroblast. The resulting embryo was induced to begin division. It was cultured until it reached the [[blastocyst]] stage, then implanted into a domestic horse [[Surrogacy|surrogate]] mare,<ref name=":1" /> which carried the embryo to term and delivered a foal with the Przewalski horse DNA of the long-deceased stallion.

The cloned horse was named Kurt, after Dr. [[Kurt Benirschke]], a [[geneticist]] who developed the idea of cryopreserving genetic material from species considered to be endangered. His ideas led to creating the Frozen Zoo as a genetic library.<ref>{{Cite web|title=Kurt Benirschke (1924-) {{!}} The Embryo Project Encyclopedia|url=https://embryo.asu.edu/pages/kurt-benirschke-1924|access-date=2020-11-15|website=embryo.asu.edu|archive-date=30 October 2020|archive-url=https://web.archive.org/web/20201030173303/https://embryo.asu.edu/pages/kurt-benirschke-1924|url-status=live}}</ref> In 2021, Kurt was relocated to the breeding herd at the [[San Diego Zoo Safari Park]].<ref>{{cite web |last1=Beale |first1=Mel |title=Why a cloned foal born at a USA zoo is key to the survival of his endangered breed |url=https://www.yourhorse.co.uk/news/cloned-foal-key-survival-endangered-breed/ |website=Your Horse |language=en |date=10 June 2021}}</ref><ref name="SDZoo 2022">{{cite web |url= https://stories.sandiegozoo.org/2022/10/20/a-clone-and-his-mentor/ |title= A Clone and His Mentor |author= <!--Not stated--> |date= 20 October 2022 |website= sandiegozoo.org |publisher= [[San Diego Zoo]] |access-date= 29 February 2024 |archive-date= 29 February 2024 |archive-url= https://web.archive.org/web/20240229234821/https://stories.sandiegozoo.org/2022/10/20/a-clone-and-his-mentor/ |url-status= dead }}</ref> In order to integrate him into the existing herd, Kurt was partnered with a young female named Holly, a few months older than him, in order to allow him to learn the social and communication behaviors of wild Przewalski's horses. On reaching maturity at three to four years of age, Kurt is intended to become the breeder stallion for the San Diego Zoo herd to pass Kuporovic's genes into the larger captive Przewalski's horse population and thereby increase the genetic variation of the species.<ref name=":0" /><ref name="SDZoo 2022"/>

In 2023, a genetic twin of Kurt, named Ollie, was born from cloning with the help of the San Diego Zoo Global Frozen Zoo. It is the first reported case of any endangered species having more than one clone successfully produced. This individual eventually joins Kurt and Holly at the San Diego Zoo Safari Park.<ref>{{cite web|author=Black, A.|date=April 19, 2023|title=Second Przewalski horse born from cloning|url=https://www.cbs8.com/article/news/local/second-cloned-przewalski-horse/509-4c46e2f6-c583-4cd6-9b51-5065124f3e14|website=CBS News 8|access-date=April 20, 2023}}</ref><ref name="Novak et al">{{cite bioRxiv |biorxiv=10.1101/2023.12.20.572538 |title=Endangered Przewalski's horse, Equus przewalskii, cloned from historically cryopreserved cells |date= 9 January 2024 |last1=Novak |first1=Ben J. |last2=Ryder |first2=Oliver A. |last3=Houck |first3=Marlys L. |last4=Putnam |first4=Andrea S. |last5=Walker |first5=Kelcey |last6=Russell |first6=Lexie |last7=Russell |first7=Blake |last8=Walker |first8=Shawn |last9=Arenivas |first9=Sanaz Sadeghieh |last10=Aston |first10=Lauren |last11=Veneklasen |first11=Gregg |last12=Ivy |first12=Jamie A. |last13=Koepfli |first13=Klaus-Peter |last14=Rusnak |first14=Anna |last15=Simek |first15=Jaroslav |last16=Zhuk |first16=Anna |last17=Phelan |first17=Ryan }}</ref> Due to having been conceived through the transfer of a somatic cell nucleus into an egg cell obtained from a domestic horse donor, Kurt and Ollie both display the mitochondrial genome of domestic horses instead of belonging to a Przewlaski horse mithocondrial clade.<ref name="Novak et al"/> However, as [[Mitochondrial_DNA#Mitochondrial_inheritance|mitochondrial DNA is maternally inherited]], they will not pass on these domestic horse genes.

== See also ==
{{Portal|Mammals|Horses}}
* [[Mongolian horse]] (domestic)
* [[Mongolian wild ass]]

==Notes==
{{Notelist}}

==References==
{{Reflist|refs=

<ref name=IUCN2011>{{cite news | url = http://www.iucn.org/about/work/programmes/species/red_list/?8548/Another-leap-towards-the-Barometer-of-Life | title = Another leap towards the Barometer of Life | work = International Union for the Conservation of Nature | date = 10 November 2011 | archive-url = https://web.archive.org/web/20111115014738/http://www.iucn.org/about/work/programmes/species/red_list/?8548%2FAnother-leap-towards-the-Barometer-of-Life | archive-date = 15 November 2011 | url-status = dead}}</ref>

<ref name=ZSL051219>{{cite news | url = http://www.zsl.org/info/media/press-releases/null,1790,PR.html | title = An extraordinary return from the brink of extinction for worlds last wild horse | work = ZSL Living Conservation | date = 19 December 2005 | archive-url = https://web.archive.org/web/20120212234213/http://www.zsl.org/info/media/press-releases/null,1790,PR.html | archive-date = 12 February 2012 | url-status = dead}}</ref>

<ref name=boyd94>{{cite book | url = https://books.google.com/books?id=Bvg99Qq54nUC | title = The History of Przewalski's Horse| work=Przewalski's Horse | last1=Bouman | first1=Inge | last2=Bouman | first2=Jan | editor-first = Lee | editor-last = Boyd | editor2-first=Katherine A. | editor2-last=Houpt | year = 1994 | pages = 5–38 | publisher = SUNY Press| isbn = 9780791418895}}</ref>

<ref name="lau 2009 199–208">{{cite journal |title=Horse Domestication and Conservation Genetics of Przewalski's Horse Inferred from Sex Chromosomal and Autosomal Sequences |last=Lau |first=Allison |author2=Lei Peng |author3=Hiroki Goto |author4=Leona Chemnick |author5=Oliver A. Ryder |author6=Kateryna D. Makova |year=2009 |journal=Mol. Biol. Evol. |volume=26 |issue=1 |pages=199–208 |doi=10.1093/molbev/msn239 |pmid=18931383 |doi-access=free}}</ref>

<ref name=kavar08>{{cite journal |title=Domestication of the horse: Genetic relationships between domestic and wild horses |last=Kavar |first=Tatjana |author2=Peter Dovč |year=2008 |journal=Livestock Science |volume=116 |issue=1–3 |pages=1–14 |doi=10.1016/j.livsci.2008.03.002}}</ref>

<ref name=ChinaancientDNA>{{cite journal |title=Ancient DNA provides new insights into the origin of the Chinese domestic horse |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 |year=2009 |journal=Journal of Archaeological Science |volume=36 |issue=3 |pages=835–842 |doi=10.1016/j.jas.2008.11.006|bibcode=2009JArSc..36..835C }}</ref>

<ref name=GBE2011>{{cite journal| first1=O A | last1=Ryder| first2=A R | last2=Fisher| first3=B | last3=Schultz| first4=S | last4=Kosakovsky Pond| first5=A | last5=Nekrutenko| first6=K D | last6=Makova| title=A massively parallel sequencing approach uncovers ancient origins and high genetic variability of endangered Przewalski's horses| journal=Genome Biology and Evolution| volume=3| pages=1096–1106| year=2011| doi=10.1093/gbe/evr067| pmid=21803766| pmc=3194890}}</ref>

<ref name=STWH>{{cite web | url = http://www.savethewildhorse.org/takhi.454.html |archive-url=https://web.archive.org/web/20120719031009/http://www.savethewildhorse.org/takhi.454.html |archive-date=19 July 2012| title = The Takhi | publisher= International Takhi-Group | access-date= 25 October 2010}}</ref>

<ref name=IUCN>{{cite iucn|author1=King, S.R.B.|author2=Boyd, L.|author3=Zimmermann, W.|author4=Kendall, B.E.|year=2015|title=''Equus ferus''|errata=2016|page=e.T41763A97204950|doi=10.2305/IUCN.UK.2015-2.RLTS.T41763A45172856.en|access-date=7 January 2024}}</ref>

<ref name=takhleaflet>{{citation | title = Przewalski's Horse - the last wild horse | publisher = Association Takh | url = http://www.takh.org/ | access-date = 1 January 2012 | archive-date = 16 November 2010 | archive-url = https://web.archive.org/web/20101116022105/http://www.takh.org/ | url-status = live }}</ref>

<ref name=bbc060420>{{cite news | first=Stephen | last=Mulvey | title=Wildlife defies Chernobyl radiation | date=20 April 2006 | url=http://news.bbc.co.uk/2/hi/europe/4923342.stm | work=BBC News | access-date=3 October 2007 | archive-date=25 December 2018 | archive-url=https://web.archive.org/web/20181225154205/http://news.bbc.co.uk/2/hi/europe/4923342.stm%20 | url-status=live }}</ref>

<ref name=AP080617>{{cite news | url = http://www.today.com/id/25211052/43235154 | title = Rare horse gets reverse vasectomy | first = Brett | last = Zongker | agency = Associated Press | publisher = Today.com / NBC News | date = 17 June 2008 | access-date = 6 April 2013 | archive-url = https://web.archive.org/web/20130512034541/http://www.today.com/id/25211052/43235154 | archive-date = 12 May 2013 | url-status = dead}}</ref>

<ref name=BC8204>{{cite journal | title = Cooperative breeding programme for the Mongolian wild horse ''Equus przewalskii'' in the United States | first1 = Oliver A. | last1 = Ryder | first2 = Elizabeth A. | last2 = Wedemeyera | journal = Biological Conservation | volume = 22 | issue = 4 | date = April 1982 | pages = 259–271 | doi=10.1016/0006-3207(82)90021-0| bibcode = 1982BCons..22..259R }}</ref>

<ref name=PHAI>{{cite web | url = http://www.thehorse.com/articles/32317/przewalskis-horse-foal-born-via-artificial-insemination | title = Przewalski's Horse Foal Born via Artificial Insemination | publisher = TheHorse.com | date = 2 August 2013}}</ref>

}}

==Further reading==
{{refbegin}}
* {{cite book |author1=Boyd, Lee |author2=Houpt, Katherine A. |year=1994 |url=https://books.google.com/books?id=Bvg99Qq54nUC |via=Google Books |title=Przewalski's Horse: The history and biology of an endangered species |place=Albany, New York |publisher=[[State University of New York Press]] |isbn=978-0-7914-1889-5 |oclc=28256312 }}
* {{cite web |publisher=Forestry Commission, Wales, U.K. |title=FC Wales turns clock back thousands of years with 'wild' solution to looking after ancient forest site |type=Media release |id=No: 7001 |date=16 September 2004 |url=http://www.forestry.gov.uk/newsrele.nsf/c06604a4b305b4a680256a1c003c773c/4853459c0456cc6880256f0800494861!OpenDocument |df=dmy-all |archive-url=https://web.archive.org/web/20060706211010/http://www.forestry.gov.uk/newsrele.nsf/c06604a4b305b4a680256a1c003c773c/4853459c0456cc6880256f0800494861!OpenDocument |archive-date=6 July 2006 }}
* {{cite journal |publisher=International Commission on Zoological Nomenclature |year=2003 |id=Opinion 2027 (Case 3010) |title=Usage of 17&nbsp;specific names based on wild species which are pre-dated by or contemporary with those based on domestic animals (Lepidoptera, Osteichthyes, Mammalia): conserved. |journal=Bull. Zool. Nomencl. |volume=60 |pages=81–84 |url=http://www.iczn.org/BZNMar2003.htm |archive-url=https://web.archive.org/web/20060224225456/http://www.iczn.org/BZNMar2003.htm |archive-date=2006-02-24 |df=dmy-all }}
* {{Cite journal |last=Ishida |first=Nobushige |year=1995 |title=Mitochondrial DNA sequences of various species of the genus ''Equus'' with special reference to the phylogenetic relationship between Przewalskii's wild horse and domestic horse |journal=Journal of Molecular Evolution |volume=41 |issue=2 |pages=180–188 |doi=10.1007/BF00170671 |pmid=7666447 |bibcode=1995JMolE..41..180I |s2cid=2884878 |display-authors=etal}}
* {{Cite journal |last=Jansen |first=Thomas |year=2002 |title=Mitochondrial DNA and the origins of the domestic horse |journal=[[Proceedings of the National Academy of Sciences|PNAS]] |volume=99 |issue=16 |pages=10905–10910 |doi=10.1073/pnas.152330099 |pmid=12130666 |pmc=125071 |bibcode=2002PNAS...9910905J |display-authors=etal|doi-access=free }}
* {{Cite journal |last=King |first=S. R. B. |author2=Gurnell, J. |year=2006 |title=Scent-marking behaviour by stallions: an assessment of function in a reintroduced population of Przewalski horses (''Equus ferus przewalskii'') |journal=Journal of Zoology |volume=272 |issue=1 |pages=30–36 |doi=10.1111/j.1469-7998.2006.00243.x }}
* {{cite book |author=van&nbsp;Cleaf, K. |title=Przewalski's Horses |place=Edina, MN |publisher=ABDO Pub. Co. |year=2006 |edition=Print}}
* {{cite book |author1=Wakefield, S. |author2=Knowles, J. |author3=Zimmermann, W. |author4=Van Dierendonck, M. |year=2002 |chapter=Status and action plan for the Przewalski's Horse (''Equus ferus przewalski'') |editor=Moehlman, P.D. |title=Equids: Zebras, Asses and Horses. Status Survey and Conservation Action Plan |pages=82–92 |department=IUCN/SSC Equid Specialist Group |publisher=IUCN |place=Gland, Switzerland and Cambridge, UK |chapter-url=https://is.muni.cz/el/1431/jaro2007/Bi8710/E-przewalskii.pdf }}
* {{Cite news |first=John Noble |last=Wilford |title=Foal by Foal, the Wildest of Horses Is Coming Back |url=https://www.nytimes.com/2005/10/11/science/11hors.html |work=New York Times |date=11 October 2005 |df=dmy-all }}
* {{cite web |url=http://www.welcome2mongolia.com/travel-and-tourism-of-mongolia/mongolia-travel/financial-losses-puts-at-risk-chinese-program-of-reintroducing-przewalskis-horses |archive-url=https://web.archive.org/web/20090529041428/http://www.welcome2mongolia.com/travel-and-tourism-of-mongolia/mongolia-travel/financial-losses-puts-at-risk-chinese-program-of-reintroducing-przewalskis-horses |archive-date=2009-05-29 |df=dmy-all |title=Financial losses puts at risk Chinese program of reintroducing Przewalski's horses |website=Welcome2Mongolia }}
* {{cite AV media |url=http://video.pbs.org/video/2157025070/ |medium=video |title=[no title given] |website=PBS |access-date=25 October 2013 |archive-date=28 November 2015 |archive-url=https://web.archive.org/web/20151128102430/http://video.pbs.org/video/2157025070/ |url-status=dead }}
* {{cite web |url=http://www.china.org.cn/english/environment/237442.htm |title=Returning Home — Przewalski's horse reintroduction project |website=China.org.cn |author1=Chen, Xia |author2=Huang, Shan |date=28 December 2007 }}
** {{cite web |author=Cao Jie |title=Przewalski's Horse Reintroduction Project of China |url=http://www.china.org.cn/english/environment/237442.htm }}
* {{cite web |url=http://www.equids.org/aswhorse.php |title=Przewalski's horse - ''Equus ferus przewalskii'' |publisher=IUCN SSC Equid Specialist Group }}
* {{cite journal |last1=Slivinska |first1=Kateryna |last2=Kopij |first2=Grzegorz |year=2011 |title=Diet of the Przewalski's Horse Equus Przewalskii in the Chernobyl Exclusion Zone |journal=Polish Journal of Ecology |volume=59 |pages=841–47}}
* {{cite journal |last1=Scheibe |first1=KM |last2=Eichhorn |first2=K. |last3=Kalz |first3=B. |last4=Streich |first4=WJ |last5=Scheibe |first5=A. |year=1998 |title=Water consumption and watering behavior of Przewalski horses (''Equus ferus przewalskii'') in a semi-reserve |journal=Zoo Biology |volume=17 |issue=3 |pages=181–192 |doi=10.1002/(sici)1098-2361(1998)17:3<181::aid-zoo3>3.3.co;2-m}}
* {{cite journal |last1=Brinkmann |first1=Lea |last2=Gerken |first2=Martina |last3=Riek |first3=Alexander |year=2012 |title=Adaptation Strategies to Seasonal Changes in Environmental Conditions of a Domesticated Horse Breed, the Shetland Pony (''Equus ferus caballus'') |journal=Journal of Experimental Biology |volume=215 |issue=7 |pages=1061–1068 |doi=10.1242/jeb.064832 |pmid=22399650|doi-access=free|bibcode=2012JExpB.215.1061B }}
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* {{cite journal |title=A massively parallel sequencing approach uncovers ancient origins and high genetic variability of endangered Przewalski's horses |journal=Genome Biology and Evolution |date=1 January 2011 |issn=1759-6653 |pmc=3194890 |pmid=21803766 |pages=1096–1106 |volume=3 |url=http://gbe.oxfordjournals.org/content/3/1096 |doi=10.1093/gbe/evr067 |language=en |first1=Hiroki |last1=Goto |first2=Oliver A. |last2=Ryder |first3=Allison R. |last3=Fisher |first4=Bryant |last4=Schultz |first5=Sergei L. Kosakovsky |last5=Pond |first6=Anton |last6=Nekrutenko |first7=Kateryna D. |last7=Makova |archive-url=https://web.archive.org/web/20150727074921/http://gbe.oxfordjournals.org/content/3/1096 |archive-date=27 July 2015 |url-status=dead |df=dmy-all }}
* {{cite book |author1=Heptner, V.G. |author2=Nasimovich, A.A. |author3=Bannikov, A.G. |author4=Hoffman, R.S. |year=1988 |url=https://archive.org/details/mammalsofsovietu11988gept |title=Mammals of the Soviet Union |volume=I |place=Washington, DC |publisher=Smithsonian Institution Libraries and National Science Foundation }}
* {{cite journal |url=https://zenodo.org/records/1449268/files/article.pdf |title=Environment and race |first=William |last=Ridgeway |author-link=William Ridgeway |journal=[[The Geographical Journal]] |volume=32 |year=1908 |pages=405–412, esp. 407 |doi=10.2307/1776930 |publisher=Royal Geographical Society |jstor=1776930 |issue=4 |bibcode=1908GeogJ..32..405R |archive-date=19 November 2023 |access-date=19 December 2023 |archive-url=https://web.archive.org/web/20231119000358/https://zenodo.org/records/1449268/files/article.pdf |url-status=live }}
{{refend}}

==External links==
{{Commons category}}
{{Wikispecies|Equus ferus przewalskii}}
* {{cite web |website=ARKive |url=http://www.arkive.org/species/GES/mammals/Equus_ferus_przewalskii/ |archive-url=https://web.archive.org/web/20060507100326/http://www.arkive.org/species/GES/mammals/Equus_ferus_przewalskii/ |archive-date=2006-05-07 |title=images and movies of the Przewalski's horse (''Equus ferus przewalskii'')}}
* {{cite web |url=http://www.przewalskihorse.nl/ |title=Details of the re-introduction program for Przewalski's horse}}
* {{cite web |url=http://www.takhi.org/cms/index.php?=&lang=en |archive-url=https://web.archive.org/web/20060928155519/http://www.takhi.org/cms/index.php?=&lang=en |archive-date=2006-09-28 |title=Umbrella organization of all institutions participating in the reintroduction of takhis in Mongolia}}
* {{cite web |url=http://www.takh.org/ |publisher=Association Takh |title=Przewalski horse conservation organization, reintroduced the species to Mongolia in 2004 and 2005 and continues research and conservation on the Mongolian steppe}}

{{Perissodactyla}}
{{Equus}}
{{Taxonbar|from=Q22712}}
{{Authority control}}

[[Category:Horse subspecies]]
[[Category:Mammals of Mongolia]]
[[Category:Mammals of Central Asia]]
[[Category:Mammals of East Asia]]
[[Category:Mammals of Russia]]
[[Category:Natural history of China]]
[[Category:Endangered fauna of Asia]]
[[Category:Mammals of Europe]]
[[Category:Mammals described in 1881]]