by Valerie Wong (’24) | February 2, 2024
In 2018, the northern white rhinoceros was declared functionally extinct with the death of its last male, Sudan. Now, new advancements in fertility science could provide a glimmer of hope for the critically endangered subspecies.
Northern white rhinos were once prevalent throughout central Africa. However, illegal poaching due to political instability decimated the wild population. These poachers are driven by poverty; rhino horns are more valuable by weight than gold and diamonds. Now, only two infertile females—Najin and Fatu—remain, living under constant surveillance in the Ol Pejeta Conservancy in Kenya.
A team at BioRescue, a consortium dedicated to combating extinctions, has made promising advancements in the field of in vitro fertilization (IVF) that could save the northern white rhino population with the help of their southern subspecies. The team collected sperm from Athos, a southern white rhino at the Zoo Salzburg in Austria, and eggs from Elenore, a southern white rhino at the Pairi Daiza Zoo in Belgium. Then, in September 2023, they implanted the lab-created embryo in a southern white rhino named Curra at the Ol Pejeta Conservancy.
Tragically, Curra passed away in November 2023 due to an unrelated bacterial infection. However, researchers found that she had been seventy days pregnant at the time of her death. The fetus was found to be developing well, with a 95% chance of survival if carried to term. Researchers hope this method can be applied to the northern white subspecies as well.
Currently, thirty northern white rhino embryos exist, stored in liquid nitrogen at facilities in Italy and Germany. BioRescue hopes to implant these embryos in a southern white rhino mother to revive the species as soon as May or June of this year. They will then be able to reunite the new rhino with the remaining two in Kenya.
Unfortunately, IVF alone will not be enough to save the subspecies from extinction. All thirty existing embryos were created by eggs from Fatu and sperm from two deceased males, meaning that there is little genetic diversity in the gene pool. To resolve this, researchers are trying experimental procedures such as gene editing and creating sperm and eggs from stem cells. If successful, researchers hope to create five to six more pregnancies in the coming months.
The process of using IVF in rhinos is not without criticism. Some argue that too much money and resources are being poured into the conservation of a functionally extinct species when they could be used more effectively to save lesser-known species. But as Thomas Hilebrandt at the Leibniz Institute for Zoo and Wildlife Research argues, “it is our responsibility to save every species humans have the capability to save, especially because humans caused the degradation of rhino populations to begin with.”
The future of white rhinos is becoming more and more encouraging because of these new advancements. Southern white rhinos have risen in population to over 16,000 individuals, and poaching rates have gone down significantly since 2018. For the northern white rhinos, new IVF technology provides a last hope for the subspecies. A successful pregnancy could even pave the way for conservation efforts of the Sumatran rhino, a critically endangered species with only forty individuals remaining in the wild. After many trials and tribulations, these conservation efforts have been a resounding success, proving that it is possible for humans to mitigate some of the damage they have caused to species around the world.
