Last Known Male White Rhino Guarded by Armed Rangers in Kenya International experts are trying to get the 42-year-old rhino to reproduce.

 -- Four armed rangers are guarding what is believed to be the world’s only remaining male northern white rhino around the clock as international experts attempt to facilitate his reproduction in Kenya.

The Ol Pejeta Conservancy in Kenya made a deal in 2009 with the Dvur Kralove Zoo in the Czech Republic and acquired four white rhinos -- Najin, Fatu, Sudan and Suni.

Richard Vigne, CEO of Ol Pejeta Conservancy, told ABC News that the aim of the relocation was to improve the chances of reproduction by having them live in more natural conditions.

“While Kenya has not been a white rhino range state in the last 200 years, evidence from fossils and cave paintings in Kenya and northern Tanzania suggests that the white rhinoceros was widespread and a part of the East African savanna fauna until 3,000 years ago or less,” the IUCN’s Red List of Endangered Species reports on its website.

Among the four acquired by Kenya, two were males. However, shortly after the San Diego Zoo’s male white rhino died in December, one of Kenya’s male white rhinos died, leaving 42-year-old Sudan as the only known male still alive.

Elaborate security operations are spread out on the Ol Pejeta Conservancy's 3,229-square-foot property, and officials are paying particular attention to white rhinos who are relatively approachable, Vigne told ABC News.

In addition to having armed guards and a team dedicated to the rhinos' well-being, efforts also are being made to prevent poaching.

“Because of the poaching crisis, one of the measures was to remove horns,” Vigne said. "Not all of it, but hopefully enough to reduce their attractiveness for poachers.”

In recent years, poaching levels have increased significantly in many African countries, including South Africa.

“Declining state budgets for conservation in real terms, declining capacity in some areas and increasing involvement of Southeast Asians in African range states are all of concern,” according to the IUCN’s Red List of Endangered Species website.

“In Kenya, we have made progress in the last eight to 12 months and, touch wood, it will continue,” Vigne said

He hopes there is enough time left, perhaps to conduct in vitro fertilization and make Sudan the rhino reproduce.