Najin and Fatu are the last two northern white rhinos on the planet and they are both female and cannot carry pregnancies.
Scientists around the world are now in a race against time to save the species at the Ol Pejeta Conservancy in Laikipia in Kenya.
"Having the last two northern white rhino is a clear symbol of what extinction means and because these animals are not able to speak for themselves, we act as their voice," said Zacharia Mutai, Northern White rhino keeper, at Ol Pejeta.
How to save a species
The plan is to use eggs harvested by the two females and sperm collected from male northern whites saved before they died.