There are only two female northern white rhinos left in the world (the lone male, Sudan, died in March), and they're infertile, but researchers are hoping new efforts on the reproduction front will stave off the end of the species. The world's first "test tube" rhinos have arrived, hybrid embryos created by fertilizing eggs from southern white rhinos with frozen sperm from northern white males. Those embryos, now themselves frozen for future implantation in southern white rhinos or hybrids, show "for the first time that modern technology can offer some options for conservation when the situation gets very bad," co-author of the study, published in the Nature Communications, Cesare Galli tells CNN. Another co-author, Jan Stejskal, notes that artificial insemination and natural breeding initiatives over the past 20 years had failed to keep the species going.
In addition, researchers were able to extract stem cells from southern white rhinos, which can be used to make eggs and sperm to create more embryos; frozen skin cells previously taken from northern white rhinos also exist as potential embryo sources. ScienceNews notes pure northern white rhinos could evolve from the hybrids by diluting the southern white rhino genes via selective breeding, though that would take decades. And it may be some time before we actually see a baby northern white rhino: One scientist involved with the study tells the BBC he hopes to see one born "within three years," but Galli notes it will be closer to 10. And a conservation expert tells CNN we shouldn't just rely on IVF to save any species, but be "working on all fronts," including via anti-poaching efforts and forest conservation. (One zoo tries to make its rhinos "unattractive" to poachers.)