Przewalsky´s horses had become extinct in the wild since a last sighting in 1969 and had survived only in zoos. Since the start of a re-introduction project in 1992 in Mongolia a free-living population was again established despite some setbacks. Prof. Chris Walzer and his team from the Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna have been involved in this project for many years. Due to the project's success the species´ conservation status was changed from "extinct in the wild" to "critically endangered" and eventually downgraded to "endangered" in a 2011 IUCN assessment - a great success for international wildlife conservation.
By the end of the 1960s the last free-living wild horses, known as the Przewalsky´s horse (pronounced “Pshewalsky”), were thought to be extinct in the wild. "Today it is known that the reasons for their extinction was a combination of competition for grazing land with domestic grazing animals of local livestock herders and excessive hunting," says Chris Walzer, wildlife veterinarian at the Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna (Vetmeduni Vienna). Walzer and his team have for many years been accompanying the re-introduction project that started in 1992.
It all started with only 13 animals
2012 marks the 20 year anniversary since the first Przewalsky´s horses were brought back to the Gobi Desert. They were descended from the original 13 animals that came from Mongolia to European zoos and had given birth to offspring under the care of humans. Thanks to visionary horse lovers, conservationists and farmers the descendants of those original 13 takhis, as they are called in Mongolia, have now found a new home in their old country. Since 1999, the Swiss-based International Takhi Group (ITG) is engaged in the reintroduction of the animals in the Mongolian desert. The ITG assists the Mongolian State National Park Gobi B, its camp and its rangers. Today these rangers and researchers from the Vetmeduni Vienna watch over the slowly growing wild horse herd, as Walzer explains: “Today the rangers control the herds once or twice a week. In the past, we monitored 15 animals with satellite collars to get a better idea of their home ranges and migration patterns and also to facilitate the search for the rangers.”
Competition for habitat
The takhis did not return to an uninhabited wilderness, but to a cultural landscape that has been used by humans for centuries, where the number of traditionally semi-nomadic people and their grazing livestock herds have increased since the disappearance of the wild horses. “One of the many challenges is, for example, to avoid hybridisation of the wild horses with the domestic horses of the local population, because the Przewalsky´s horse is not a wild version of the domestic horse, but actually a different species. Nevertheless, the animals can interbreed and produce fertile offspring. If one were to allow inter-breeding the unique gene pool of the few takhis would be lost within that of the domestic horse.”, explains Petra Kaczensky of the Research Institute of Wildlife Ecology, Vetmeduni Vienna. In addition, the Gobi is rich in mineral resources, and mining is changing the landscape on large scales in many areas. Where takhis roam it is primarily illegal gold miners that are currently destroying pastures mechanically.
High mortality rate at the beginning
By 2009, the population of wild horses in the Gobi had recovered to the impressive number of 138 animals. Critical to this success was finding the main cause of high early mortality in the animals: "Examinations of dead animals showed that many died of piroplasmosis, a tick-borne infectious disease," says wildlife veterinarian Walzer. "We were able to get this under control with a preventive treatment."
Setback by extreme winter
The project experienced further setbacks. The extremely dry summer of 2009, followed by an unusually long and cold winter (“Dzud”) caused the hitherto slowly growing wild horse population in the Gobi to collapse – more than half of the animals died. The disaster Winter 2009/2010 is a prime example of how vulnerable small and spatially restricted wildlife populations are in a habitat with large environmental fluctuations. It showed emphatically how important it is to think large scale, long-term and interlinked. If there were not a second re-introduction project in the forest steppes of central Mongolia, this would be bad news for the status of Przewalksy´s horses in their native country. The wild horses in Hustain Nuuru, at a distance of 1000 km from the Gobi, also suffered from the catastrophic winter, but not nearly as much. A lush spring after the harsh winter, a rainier summer of 2010 and a subsequent mild winter in 2010/2011 helped ensure that the number of animals in the Gobi is on the rise again. “For 2012, we expect an above average number of foals,” says Thomas Pfisterer, President of the ITG.
Growing infrastructure fragments habitat
A relative of the Przewalsky´s horse, the Asiatic wild ass, follows a different strategy to deal with the often unpredictable conditions of life in the barren Gobi. While the Przewalsky´s horses tend to stick to the most fertile areas of the Gobi, the wild ass is a true nomad - here today and elsewhere tomorrow - always searching out areas where conditions are right. The asses were able to dodge the most snowy areas during the disaster winter 2009/2010 and, unlike the wild horses, hardly suffered any losses. This strategy has enabled the survival of the wild asses in the arid semi-desert and desert areas of the Gobi, and for this they need a lot of space. But the extraction of raw materials and the associated infrastructure development are now threatening to fragment their habitat. “Without large-scale landscape planning that takes into account the needs of migratory species such as wild asses, goitered gazelle and Mongolian gazelle, Mongolia runs the risk of losing its charismatic ungulates", says Kaczensky.
Ecosystem and the local economy are important
Wild ass and gazelle do not carry the same symbolic value as the Takhi, the sacred horse of the Mongols. While initially the resettlement project focused purely on the Przewalsky´s horses it soon became apparent that the more wide-reaching ecological relationships in the new habitat of the animals and the economic conditions of the people living there also had to be taken into account. "The wild horse is an ideal vehicle for raising awareness on the need for the protection of the entire ecosystem of the Dzungarian Gobi ," says Pfisterer. Difficulties in predicting the availability of funding, legal problems and the growing poverty of the population, however, would continue to cause conflicts over the use of local resources. "We can only ultimately be successful through open cooperation with the local livestock herders, authorities, governors and ministries of Mongolia," he adds.
International cooperation
Otto Doblhoff-Dier, Vice-Rector for Research and International Relations of the Vetmeduni Vienna, is pleased with the success of the wild horse project and stressed the importance of international cooperation: “Since the reintroduction of the first animals in 1992, which was held in collaboration with the Mongolian government, institutions from Europe, Asia and Australia have provided additional animals. These include, for example, the Schönbrunn Zoo in Vienna and the Salzburg Zoo.” Researchers of the Vetmeduni Vienna have contributed significantly to the success of the project. "With the start of the regular veterinary examinations by Chris Walzer's team we were able to determine one of the main causes of the high mortality of the first reintroduced animals," he adds. “Furthermore, in the beginning we knew very little about the behaviour of Przewalsky´s horses in the wild. Only through constant monitoring of the animals have we begun to understand their behaviour, and thus their needs.”
(Web Editor on 09/18/2012)
