Laikipia County, Kenya - Scientists are running out of time to save the critically endangered northern white rhino. There are only three left in the world.
"Sudan", along with the other two, live in Kenya's Ol Pejeta conservancy.
At 43 years old, conservationists say that it is unlikely Sudan - the last male of the group - will live for more than another two years.
As the two female rhinos suffer from reproductive issues, it is hoped that in vitro fertilisation, or IVF, will save the species from extinction.
"[But as] both females have reproductive issues, the chances of natural breeding are now zero," said Richard Vigne, head of Ol Pejeta. "We will have to look into artificial reproductive techniques, in particular in vitro fertilisation and it's fraught with problems."
IVF has never before been successfully carried out on rhinos.
Researchers in Europe are attempting to discover how to best harvest and fertilise eggs from the two female rhinos. If their trials are successful, a surrogate mother could give birth.
However, even if the IVF research goes well, there are two further threats: poaching and disease.
"Poachers are very daring nowadays. They could attempt to breach any security detail that we put in the way. Another threat would be diseases ... that suddenly kill an animal before you get a chance to treat them," said veterinarian Stephen Ngulu.
In 2015, rhino poaching increased for the sixth year in a row. The International Union for Conservation of Nature says at least 1,338 rhinos were killed last year for their horns.
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