by Floro Mercene
Sudan was different from his wild peers. In 1975, he was captured by animal trappers at the age of 2, and moved to Dvůr Králové Zoo in the Czech Republic. In 2009, he and three others – Najin, Fatu, and an unrelated male, Suni – were moved to the Ol Pejeta Conservancy to take part in a last-ditch breeding program.
It didn’t work. None of the females achieved a confirmed pregnancy. In 2014, Suni died. And now Sudan has died at age of 45 (their life expectancy is 40-50 years) leaving only two females of its subspecies alive in the world.
Scientists think that the only way to preserve some northern white-rhino genes is to artificially interbreed them with southern whites, the closest living relative to the rare northern whites, and the work is now underway. A rhino’s ovaries lie two meters within its body, so collecting eggs requires shoulder-length gloves and a lot of dexterity. They are now ready to try on Najin and Fatu, whose eggs could then be fertilized in a laboratory.
The one way to save the northern white is to now artificially inseminate their eggs with stored sperm from Sudan and other males, and implant the resulting eggs into females of the closely related southern white rhino. This way has never been done before with rhinos.
Another possible approach involves taking frozen cells from Sudan and other northern whites, transforming them into stem cells, and nudging those into becoming sperm and eggs.
“It is our moral obligation to try to save them. We are the only ones, perhaps with San Diego Zoo, who have enough collected biological material to do so. We are aware that our chances are slim, but the hopes are still alive, “says Premysl Rabas, director of the Dvůr Králové Zoo.