Przewalski’s Horse Conservation at the Smithsonian’s National Zoo
For over two decades scientists at the Smithsonian’s National Zoo have been working with this critically endangered species. The wild equid is considered “extinct in the wild” by the World Conservation Union. Through reintroduction projects in Mongolia, nearly 300 horses now roam freely in the wild. However the horse is still absent from much of its former geographic range which spanned regions in Mongolia, China, Russia, and Kazakhstan.
Conserving Przewalski’s Horses in Captivity
The National Zoo currently manages the Species Survival Plan for the entire captive North American population of Przewalski’s horses. The Species Survival Plan is a cooperative breeding program for threatened and endangered species among accredited zoos in North America.
For the past few years, the captive population of Przewalksi’s horses has been at risk of losing the ability to sustain itself. This means that there are not enough animals reproducing to maintain a genetically healthy population. To reinvigorate the population, National Zoo scientists have implemented an intensive captive breeding program that will increase reproduction rates through natural breeding as well as artificial reproduction techniques.
In 2006, the Zoo’s Conservation and Research Center imported two mares from Europe to breed with one of their stallions—the most genetically valuable male in the North American population who has never sired offspring. The two European mares are currently pregnant by this male, and should give birth later this fall.
Through research, scientists are gathering baseline knowledge about the reproductive fitness of mares and stallions within the North American herds, studying the reproductive hormone patterns of mares, and developing safe and effective methods for semen collection and semen cryopreservation (freezing) in the likely event of artificial inseminations.
Artificial insemination has a great potential for increasing breeding efficiency in small populations and for creating genome resource banks—or frozen repositories. These resource banks can serve as insurance policies against unforeseen catastrophes in the wild, such as a pandemic disease. Genome resource banks combined with artificial insemination could be particularly valuable in Przewalski’s horses for many reasons including ensuring reproduction between genetically valuable but behaviorally incompatible pairs, eliminating the risks associated with animal transport, and providing an avenue for infusing genes between wild (reintroduced) stocks and captive populations.
Conserving Przewalski’s Horses in the Wild
National Zoo scientists and veterinarians are currently working with the Cologne Zoo and the Wild Horse Breeding Centre (WHBC) in Xinjiang, China, to monitor and protect a reintroduced population of Przewalski’s horses in northwestern China. The species went extinct in the wild in the 1960s, but with the transfer of horses from western zoos in the 1980s, the WHBC eventually established a captive population of more than 150 horses. In 2001, the WHBC began reintroductions to the 1.7 million hectare Kalameili Nature Reserve (KNR) located near the WHBC.
There are serious challenges to creating a self-sustaining wild Przewalski’s horse population in the area, which include marginal habitats within reintroduction sites, competition with livestock for available grazing pasture, and interbreeding with domestic horses.
Local Kazak herders depend on the KNR for pasture during the harsh winters when they bring thousands of livestock into the reserve along with domestic horses used for transport. In an attempt to find win-win scenarios that benefit both wildlife and local people, National Zoo scientists and their colleagues have held training workshops and undertaken community surveys in the areas surrounding the KNR to determine the current socio-economic needs of local herders and to develop ideas for alternative livelihood strategies.
In order to monitor the released horse groups, National Zoo veterinarians deployed satellite tracking collars on a few selected animals. The collars record horse movements and emit a signal that helps field staff to locate them in the field, allowing staff to observe horse behavior and assess their health and status. National Zoo scientists use location data from the collars combined with other spatial data in a Geographic Information System (GIS) to map horse movements, determine their habitat requirements and assess potential threats.
Long-range objectives include conducting post-release monitoring and ecological studies and improving restoration and management strategies, as well as building capacity for our colleagues in China. The ultimate goal is to help ensure establishment of a self-sustaining, free-roaming population of Przewalski’s horses within the KNR.