There were more than 2,000 northern white rhinos remaining as recently as 1960.
By 1984, poaching had decimated the population.
On December 20, 2009, four of the last eight known northern white rhinos were relocated from captivity back to the wild in a last bid to save them from extinction.
The four rhinos - Sudan, Suni, Fatu and Najin - were moved from Dvur Králové Zoo in the Czech Republic to the Ol Pejeta Conservancy in Laikipia, Kenya.
