156 • Technologies To Maintain Biological Diversity 



Box 6-E.— Captive Breeding and Przewalski's Horse 



Offsite conservation through captive breeding has prevented the extinction of such animal species 

 as the European bison, Pere David's deer, Arabian oryx, and the wild species of horse most closely 

 related to all domestic horse breeds. This latter species, known as Przewalski's horse, has never been 

 domesticated and is known historically to have come from Mongolia and China. Although it is not 

 certain whether it is the direct ancestor of the oldest breeds of domestic horse, this species differs 

 from all domestic horses in possessing a different number of chromosomes, as well as having other 

 genetic variations. First brought to the attention of European scientists in the late 1800s by the Polish 

 explorer N.M. Przewalski, who explored and mapped Mongolia for the Russian czar, the species has 

 a bulky head, erect mane, lack of forelock, and buckskin-dun coloration; it sheds its coat in a manner 

 different from domestic breeds. 



This species, Equus przewalskii, was already in decline at the time Colonel Przewalski obtained 

 a killed specimen and forwarded the skeleton and skin to the Imperial Zoological Museum at St. 

 Petersburg. The horses depicted on the famous cave paintings at Lascaux in southern France have 

 the same morphological features as Przewalski's horse. 



The publication in 1881 of the description of a new species of horse attracted considerable attention 

 from zoologists and horse breeders. By 1902, 52 animals had been captured and were eventually 

 distributed in the Ukraine, Europe, and North America. In Mongolia, young foals were captured shortly 

 after they were born, because attempts to capture adult or even juvenile horses were fruitless. The 

 captured foals were nursed by domestic mares bred to produce their own foals coincident to the capture 

 of the young Przewalski's horses. The Przewalski's horse is thought now to be extinct in its natural 

 habitat. None have been seen since 1967, in spite of annual search efforts by the Joint Soviet-Mongolia 

 Biological Expedition. More than 550 now live in some 70 zoological institutions on all continents 

 except Africa and South America. An international studbook contains the pedigrees of all animals 

 and traces back to 13 individual animals. 



Przewalski's horses can interbreed with their domestic relative, and the hybrids produced by suc| 

 crosses were allegedly incorporated into the Russian czar's cavalry stud. 



The disappearance of the species was probably due to hunting and, more important, to restricted 

 access to limited water supplies that were monopolized by nomads and their herds of domestic animals. 

 The horses' habitat remains, and plans exist to restore the species to its former range in Mongolia. 

 This restoration effort involves the cooperative activities of zoological parks in the United States, 

 the Soviet Union, the United Kingdom, and West and East Germany. Animals will be provided by 

 zoological parks from their expanding populations. 



The offsite conservation of species and preservation of genetic diversity that these efforts represent 

 may play an increasing role in strategies to prevent extinction. The interaction through movement 

 of individuals from offsite to onsite conservation facilities reduces the chance of extinction and 

 simultaneously provides access to rare species for educational and research purposes. 



SOURCE: Dr. Oliver Ryder, Research Department. San Diego Zoo. 



terspecific embryo transfers have occurred to horse, and Przewalski's horse to pony 



from mouflon (wild sheep) to domestic (see box 6-E) (9). 



sheep, gaur to cattle, bongo to eland, zebra 



The objectives of developing and using fiber production on an international scale is 



genetic diversity differ between wild and do- of paramount importance. In this context, the 



mestic animals. For domestic animals, the po- most pertinent technologies are those that fa- 



tential contribution of rare breeds to food and cilitate the international movement and evalu- 



