There Are Now Only 4 Northern White Rhinos Left On Earth

A rhino's death in the Czech Republic leaves the species on the "brink of extinction."

And then there were four. 

The northern white rhinoceros, one of the world's most critically endangered species, inched a step closer to total extinction after one died in a Czech zoo on Monday, leaving just four of the highly hunted animals left on earth. 

The rhino, Nabiré, was 31 years old and died after suffering a ruptured cyst that was impossible to treat, zoo officials said. 

"It is a terrible loss," Premysl Rabas, director of the Dvur Kralove Zoo, where the rhino was kept, said in a statement. "Nabiré 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 a senseless human greed. Her species is on the very brink of extinction."

While Nabiré was never able to conceive naturally due to the large number of cysts on one of her ovaries, she may posthumously help the advancement of her species. Upon her death, the healthy ovary and other tissue samples were immediately taken to a lab in Italy, where scientists plan to use them to study northern white rhino reproduction.  

Widespread poaching in Africa brought the northern white rhino count from more than 2,000 in 1960 to a mere 15 in 1984, the World Wildlife Fund reports. Three of the remaining rhinos, including the only living male, live on a wildlife conservancy in Kenya and one lives at the San Diego Zoo in California. 

The remaining male rhino is kept under armed guard 24 hours a day and has been stripped of his horn to deter poachers, who rake in huge sums selling rhinoceros horn as an ingredient for Eastern medicines and as a raw material that can be carved into trinkets.