There are now approximately 306 free-ranging reintroduced and native-born Przewalski’s Horses in Mongolia (Zimmerman 2011). All Przewalski’s Horses alive today are descended from only 13 or 14 individuals, which were the nucleus of a captive breeding program (Bowling and Ryder 1987). Introgression of domestic horse blood happened not only in Halle (#229 dom.Mongol), but also in Askania Nova (#175 Domina; Bowling et al. 2003).
Between 1992 and 2004, 90 captive-born horses were transported to the Takhin Tal/Gobi B reintroduction site in Mongolia (ITG International Takhi Group, Zimmermann 2008). A further three males were translocated from Hustai National Park to Takhin Tal in 2007 (Zimmermann 2008). In 2008 there were approximately 111 free-ranging horses in this population (Zimmerman 2008, Kaczensky and Walzer 2007). In December of 2009 there were 137 individuals in the population, but due to an extremely harsh winter (dzud) the population suffered extreme mortality and by August 2010 only 49 individuals remained (Kaczensky et al. 2010, Zimmerman 2011). From 1992 to 2000, 84 horses were brought to Hustai National Park by the Foundation for the Preservation and Protection of the Przewalski Horse and Mongolian Association for Conservation of Nature and the Environment (MACNE) from reserves in Europe (King and Gurnell 2005). As of the end of 2010 this population was approximately 233 individuals (Zimmerman 2011). A third reintroduction site was started in 2004 at Seriin Nuruu in the Khomiin Tal buffer zone of the Khar Us Nuur National Park in western Mongolia (Association pour le cheval de Przewalski: TAKH). Twenty-two individuals consisting of four pre-established families and one male bachelor group were brought from Le Villaret, France between 2004 and 2005 (C. Feh pers. comm., Zimmermann 2008). In 2010, this population had 24 individuals (Zimmermann 2011).
In China, the Wild Horse Breeding Centre (WHBC) of the Department of Forestry at Kalameili Nature Reserve (KNR) in Xinjiang Uighur Autonomous Region has established a large captive population of approximately 123 Przewalski’s Horses (January 2008, Pantel et al. 2006, Zimmermann et al. 2008). Since 2007 one harem group is roaming free on the Chinese side of the Dzungarian Gobi (Xinjiang); another 60 horses are roaming free during summer time but are returned to the acclimatization pen during the winter (Zimmermann et al. 2008).
The history of population estimates and trends in Przewalski’s Horse has been described by Wakefield et al. (2002). Since the ‘rediscovery’ of the Przewalski’s Horse for western science, western zoos and wild animal parks became interested in this species for their collections. Several long expeditions were mounted to catch animals. Some expeditions came back empty-handed and some had only seen a glimpse of wild Przewalski’s Horses. It proved difficult to catch adult horses, because they were too shy and fast. Capture of foals, with possible killing of the adult harem members, was considered the only option (Bouman and Bouman 1994). Four expeditions that managed to catch live foals took place between 1897 and 1902. Fifty-three of these foals reached the west alive. Between the 1930s and the 1940s only a few Przewalski’s Horses were caught and most died. At least one mare was crossbred with domestic horses by the Mongolian War Ministry (Bouman and Bouman 1994).
Small groups of horses were reported through the 1940s and 1950s in an area between the Baitag-Bogdo ridge and the ridge of the Takhin-Shaar Nuruu (which, translated from Mongolian, means ‘the Yellow Mountain of the Wild Horse’), but numbers appeared to decline dramatically after World War II. The last confirmed sighting in the wild was made in 1969 by the Mongolian scientist N. Dovchin. He saw a stallion near a spring called Gun Tamga, north of the Takhin-Shaar Nuruu, in the Dzungarian Gobi (Paklina and Pozdnyakova 1989). Annual investigations by the Joint Mongolian-Soviet Expedition have since failed to find conclusive evidence for their survival in the wild (Ryder 1990). Chinese biologists conducted a survey in northeastern Xinjiang from 1980 to 1982 (covering the area of 88-90° E and 41°31'-47°10' N) without finding any horses (Gao and Gu 1989). The last native wild populations had disappeared.
The number of living animals in the International Studbook was 1,872 in early 2008. Of the 53 animals recorded in the Studbook as having been brought into zoological collections in the west, only 12 contributed any genes to the current living population. Of these, 11 were brought into captivity between 1899 and 1902 and the last of them died in 1939. The twelfth founder was captured as a foal in 1947. The thirteenth founder was born in 1906 in Halle (Germany) to a wild-caught stallion and a domestic Mongolian mare, and the fourteenth founder is a female born in Askania Nova (Ukraine) to a Przewalski’s Horse stallion and a domestic female of a Tarpan type. Nevertheless, the current population is genetically very close to the original wild horses (Bowling et al. 2003). In addition to animals held in captivity and those already re-introduced, there have been a number of animals released into very large enclosures (reserves). The four largest are in Le Villaret (18.13; Massif Central, France), Buchara (19.17.1; Uzbekistan), the Hortobágy-National Park (77.81; Hungary), and the Chernobyl exclusion zone (32.37; Ukraine) (information as of January 2010, Zimmermann pers. comm.).