History 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, Horse skeletons dating to the fifth to the third millennia BCE, found in Central Asia, with a range extending to the southern
Urals and the
Altai, belong to the genetic lineage of Przewalski's horse. 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. 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. Another was recorded as a gift to the
Qing emperor around 1630, its value as a gift suggesting a difficulty in obtaining them. 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. 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). 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. 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 II. The most valuable group, in
Askania Nova,
Ukraine, was shot by German soldiers during
World War II occupation, and the group in the United States had died out. as of 2019 the estimated population in the Chernobyl zone was over 100 individuals. 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. Another population is being established in the
Iberian System in Spain, the first free-roaming Przewalski's horses in Western Europe. In 2024, a
Colorado rancher discovered what appears to be a Przewalski's horse at a
Kansas livestock auction, 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. One horse, Fiona, was euthanized following apparent organ failure, while the other's fate is unreported. Since 2004, there has been a program to reintroduce Przewalski's horses that were bred in France into Mongolia. 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 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 Award in 2004. In 2004 and 2005, 22 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. After reintroduced horses had successfully reproduced, the status of the animal was changed from "extinct in the wild" to "
endangered" in 2005, , an estimated total of almost 400 horses existed in three free-ranging populations in the wild. 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
herbivores by opening the landscape through low-intensity grazing and browsing, thereby enhancing biodiversity and lowering the risk of
forest fires. Future introductions are planned. In June 2024 six mares and a stallion were reintroduced to
Kazakhstan from zoos in Europe, ten years after plans were announced to do so. 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.
Assisted reproduction and cloning 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. In 2020, the first cloned Przewalski's horse was born, the result of a collaboration between
San Diego Zoo Global,
ViaGen Equine and
Revive & Restore. The
cloning was carried out by
somatic cell nuclear transfer (SCNT), whereby a viable
embryo is created by transplanting the
DNA-containing
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. Since the oocyte used was from a domestic horse, this was an example of interspecies SCNT. 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. 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
alleles than any other horse living at the time, including otherwise lost genetic material from two of the original captive founders. 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
surrogate mare, In 2021, Kurt was relocated to the breeding herd at the
San Diego Zoo Safari Park. 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. 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 Przewalski horse mitochondrial clade. However, as
mitochondrial DNA is maternally inherited, they will not pass on these domestic horse genes. == See also ==