The northern white rhino faces imminent extinction due to poaching, with only two females remaining—a mother and daughter, living under tight security at the Ol Pejeta Conservancy, a wildlife sanctuary in Kenya.

To save the species, German scientists are conducting rhino in vitro fertilization (IVF). The scientists successfully transferred a lab-produced southern white rhino embryo to a surrogate mother after years of developing techniques to collect eggs and implant embryos more than six feet inside the two-ton animal. Achieving the first viable pregnancy required 13 attempts.

The next step is to repeat the IVF process in a northern white rhino, a close relative to the southern counterpart. Scientists will use sperm cells collected from the last male northern white rhino before his death.