A herd of endangered Przewalski horses are seen at the
Takhin Us National Park in the south-west part of Mongolia, July 16, 2012. The
Prague Zoo transported four Przewalski horses to Mongolia as part of its
efforts to reintroduce the endangered species into its native environment.
Picture taken July 16, 2012. REUTERS/Petr Josek

A Przewalski horse peers out from a container after being
unloaded from a Czech military plane at the city of Bulgan, in south-west
Mongolia, July 17, 2012. The Prague Zoo transported four Przewalski horses to
Mongolia as part of its efforts to reintroduce the endangered species into its
native environment. Picture taken on July 17, 2012. REUTERS/Petr Josek

Rangers unload containers, holding four Przewalski horses,
from trucks upon their arrival at the Takhin Tal National Park in south-west
Mongolia, July 17, 2012. The Prague Zoo transported four Przewalski horses to
Mongolia as part of its efforts to reintroduce the endangered species into its
native environment. Picture taken July 17, 2012. REUTERS/Petr Josek