Black rhinos released into African wild
It is an important landmark for African wildlife conservation.
Poaching and habitat loss have affected these creatures' numbers, even though they were once common in Africa.
In particular, Kenya has suffered huge losses, with numbers plummeting from an estimated 20,000 in the 1970s to some 500 today.
Those that remained were confined to sanctuaries.
The Kenya Wildlife Service has been working with the Zoological Society of London (ZSL) to revive rhino numbers. And now they are confident enough to begin releasing these animals back into the wild.