Nabire, a female, died Monday at just 31 years of age. She was born and died at the Dvur Kralove zoo in the Czech Republic. She was killed by the rupture of a massive cyst -- one of many that had plagued her reproductive system her entire life.
Although Nabire's cysts kept her from reproducing naturally, zookeepers had made attempts to breed her using in vitro fertilization techniques, which sadly haven't yet been successful in any rhinoceros. Of the four remaining members of the species, which has suffered great losses due to poaching and destruction of habitat, three are female. That's not a lot of genetic diversity to work with, even if breeding efforts were more successful.
And it gets worse: Of those three remaining females, two are too old to reproduce and one has health issues preventing her from doing so.
Nabire's death may indeed be the last nail in the coffin for her species.
But the Dvur Kralove zoo is holding out hope for one final chance. Nabire's healthy ovary was removed immediately upon her death, and scientists will work to harvest any eggs that they can. Those eggs would be immature -- the species only produces one mature egg every 30 days -- but the hope is that scientists can figure out how to coax them into maturity in the lab.
These artificially matured eggs could be fertilized using the sperm of the last surviving male of the species, who lives in Kenya along with two infertile females, or with any of the many sperm samples frozen throughout the years as the population dwindled.
If an egg is successfully fertilized, it could be carried to term by a member of a closely related species, like the southern white rhinoceros.
It's a long shot, but it seems like it's the species's only hope.