A female northern white rhinoceros died Monday, bringing the total number of the subspecies left in the world down to four and one step closer to extinction.
Nabire, 31, died at a zoo in Dvur Kralove in the Czech Republic on Monday evening due to a ruptured cyst, according to the New York Daily News.
"Her death is a symbol of the catastrophic decline of rhinos due to a senseless human greed. Her species is on the very brink of extinction," said zoo director Premysl Rabas.
As reported by the World Wide Fund for Nature, the northern white rhino is almost extinct due to hunting and poaching for its horns, as well as wars in Africa.
Now the subspecies' fate rests on the only living male, 42-year-old Sudan, who lives in Ol Pejeta Conservancy in Kenya under 24-hour guard, and the two females at the conservancy, Fatu and Najin.
"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, according to CNN.
Experts note further problems saying that Sudan has a low sperm count, and that while Najin could conceive, her back legs are so weak, she might not be able to support the mounted male.
"There has been recorded mating between different pairs over the last few years, but not conceptions," said Paul.
The fourth remaining rhino, Nola, lives at a zoo in San Diego but is unable to be moved to the others in Kenya due to her age.
Nabire's ovary and other tissue was taken to an Italian laboratory, where her eggs could be harvested for future artificial fertilization, the zoo said.
The remaining two northern females may serve as surrogate mothers, as well as the the northern white rhino's more populous cousin, the southern white rhino.
"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.
