Story highlights Sudan is the only male northern white rhino left worldwide

Total of 3 northern white rhinos are left worldwide -- Sudan and two females

Experts trying various ways to save the subspecies, including in vitro fertilization

Ol Pejeta Conservancy, Kenya (CNN) At first glance, Sudan looks like any other northern white rhino: stout and agile, with square lips.

He grazes under the hot sun, his massive head lowered to the ground, at the Ol Pejeta Conservancy in central Kenya.

When he's not napping in his enclosure, he waddles around the sprawling savannah, stopping briefly to drink water from a concrete hole.

But Sudan is not just any rhino. He's the last known male northern white rhino left in the world.

For an animal on the verge of extinction, the fate of the subspecies rests on his ability to conceive with the two female northern white rhinos at the conservancy.