Victoria, a southern white rhino at San Diego Zoo Safari Park, has become pregnant through artificial insemination. The breakthrough marks a giant step towards potentially saving Victoria's close relative, the northern white rhino.
Currently, only two northern white rhinos are remaining. Both are female but incapable of bearing calves.
If Victoria is successful in delivering her current calf, she may also be able to serve as a surrogate for a northern white rhino calf in the future.
With no northern white rhino eggs remaining, creating an embryo would require genetic technology. Currently, cell lines of 12 different northern white rhinos are stored in freezing temperatures. Scientists hope to transform the frozen skin cells from the dead northern white rhinos into stem cells and, eventually, into sperm and egg cells.
They could then use in vitro fertilization to create embryos and implant them in a female rhino, like Victoria.
Victoria's current pregnancy marks a crucial step as scientists seek to prove that she and other female southern white rhinos are capable of carrying a fetus to term.
Only then would they risk placing a northern white rhino embryo into a surrogate mother.