Only 4 northern white rhinos left on Earth

By Nicole Parks, CNN
2 minute read
Updated 6:45 PM EDT, Wed July 29, 2015
In December 2013, the northern white rhino Nabire walks around in her enclosure at a zoo in Dvur Kralove, Czech Republic. Nabire died of a ruptured cyst in July 2015, leaving only a few northern white rhinos left in the world.
In December 2013, the northern white rhino Nabire walks around in her enclosure at a zoo in Dvur Kralove, Czech Republic. Nabire died of a ruptured cyst in July 2015, leaving only a few northern white rhinos left in the world.
CTK/AP
In Kenya, where three of the remaining northern white rhinos live, armed guards prevent poaching.
In Kenya, where three of the remaining northern white rhinos live, armed guards prevent poaching.
Brent Stirton/Getty Images
Sudan was one of three northern white rhinos left worldwide. He <a href="http://www.cnn.com/2018/03/20/africa/kenya-northern-white-rhino-dies-whats-next/index.html">died in March</a> 2018.
Sudan was one of three northern white rhinos left worldwide. He died in March 2018.
Ol Pejeta Conservancy
As the only male, the fate of the subspecies depended on Sudan. Though he was too old to mate, scientists are hoping to impregnate other females using his sperm.
As the only male, the fate of the subspecies depended on Sudan. Though he was too old to mate, scientists are hoping to impregnate other females using his sperm.
IUCN/Richard Emslie
In addition to round-the-clock security, the conservancy has put radio transmitters on the animals and dispatches incognito rangers into neighboring communities to gather intelligence on poaching.
In addition to round-the-clock security, the conservancy has put radio transmitters on the animals and dispatches incognito rangers into neighboring communities to gather intelligence on poaching.
Courtesy Chris Morrow
Rhinos are targeted by poachers, fueled by the belief in Asia that their horns cure various ailments.
Rhinos are targeted by poachers, fueled by the belief in Asia that their horns cure various ailments.
Beverly Joubert/Rhinos Without Borders
The great white rhino hope

Story highlights

Female northern white rhino dies

Untreatable ruptured cyst caused death

Nabire's ovary harvested

Sole surviving male under 24-hour armed guard

CNN  — 

And then there were four.

Nabire, a female northern white rhino, died of a ruptured cyst on Monday at a Czech Republic Zoo, leaving only four known northern white rhinos on Earth.

The 31-year-old rhino’s cyst was so huge, it was untreatable, a rhino curator at the Dvur Kralove zoo said in a statement.

Northern White Rhino
AFP/Getty Images
video

Related video Only four northern white rhinos are left

“It is a terrible loss. Nabire was the kindest rhino ever bred in our zoo. It is not just that we were very fond of her. Her death is a symbol of the catastrophic decline of rhinos due to senseless human greed,” the zoo’s director Premysl Rabas said in a statement.

The northern white rhino has been hunted to the brink of extinction for its horn, fueled by the belief in Asia that it cures various illnesses. The highly prized horn is made of keratin – the same material that makes up human hair and fingernails.

The only living male, 42-year-old Sudan, lives in Ol Pejeta Conservancy in Kenya, under 24-hour armed guard. His horn has been cut off to deter poachers.

Ol Pejeta Conservancy photos of Rhino and Ranger
Ol Pejeta Conservancy photos of Rhino and Ranger

Related article With 1 male left worldwide, northern white rhinos under guard 24 hours

The fate of the subspecies rests on his armored shoulders, and on the two female northern white rhinos at the conservancy, Fatu and Najin, who also once lived at the Czech Republic Zoo.

“Sudan is currently old and may not be able to naturally mount and mate with a female,” said George Paul, a deputy veterinarian at the conservancy.

Internet-famous baby giraffe Kipenzi dies at Dallas Zoo

In addition, he has a low sperm count, experts say.

Najin could conceive, but her hind legs are so weak, she may be unable to support a mounted male.

“There has been recorded mating between different pairs over the last few years, but not conceptions,” said Paul.

The fourth remaining member of this dwindling subspecies, Nola, lives at the San Diego Zoo.

The dead rhino’s potentially healthy ovary and other tissue has been taken to an Italian laboratory, where her eggs may be harvested for future in vitro fertilization, the zoo said.

The northern white rhino’s cousins, the more populous southern white rhino, may serve as surrogate mothers, as could the remaining northern white rhino females.

“It is our moral obligation to try to save them. We are the only ones, perhaps with San Diego Zoo, who have enough of collected biological material to do so. We are aware that our chances are slim, but the hopes are still alive,” said Rabas.

11 wildlife experiences that could vanish in your lifetime

CNN’s Faith Karimi contributed to this report.