World’s Last Male Northern White Rhino: New IVF Success Offers Hope

The northern white rhinoceros (Ceratotherium simum cottoni) is on the brink of extinction, with only two surviving females—Najin and her daughter Fatu—remaining under 24-hour armed guard at the Ol Pejeta Conservancy in Kenya. The last male, Sudan, passed away in 2018, leaving the subspecies functionally extinct in the wild. However, a groundbreaking in vitro fertilization (IVF) breakthrough offers a glimmer of hope for their survival.

Scientists have successfully created viable northern white rhino embryos using preserved sperm from deceased males and eggs from the remaining females. This milestone, achieved through international collaboration, could pave the way for the first northern white rhino calf born via IVF—a critical step in preventing their total extinction.

The Decline of the Northern White Rhino

Historical Range and Population

Once roaming across parts of Central and East Africa, including Uganda, Chad, Sudan, and the Democratic Republic of Congo, the northern white rhino population was decimated by poaching and habitat loss. By the 1960s, an estimated 2,000 individuals existed, but unchecked hunting for their horns—highly valued in traditional medicine and as status symbols—reduced their numbers to just 15 by the 1980s.

The Last Stand in Captivity

The last wild northern white rhinos were believed to have been poached in Garamba National Park, Democratic Republic of Congo, in the early 2000s. Conservationists captured several remaining individuals and relocated them to zoos in Europe and the U.S., but breeding efforts failed due to limited genetic diversity and health complications.

In 2009, the last four fertile northern white rhinos—Sudan, Suni, Najin, and Fatu—were moved from the Dvůr Králové Zoo in the Czech Republic to Ol Pejeta Conservancy in Kenya, in a final attempt to encourage natural reproduction. Despite mating attempts, no pregnancies occurred. Suni died in 2014, and Sudan, the last male, was euthanized in 2018 due to age-related complications.

The IVF Breakthrough

Harvesting Eggs and Sperm

With natural reproduction no longer possible, scientists turned to assisted reproductive technologies. The BioRescue Project, a consortium of international researchers led by the Leibniz Institute for Zoo and Wildlife Research (IZW) in Germany, has been at the forefront of these efforts.

• Egg Collection: Using a specialized probe, veterinarians harvested immature egg cells (oocytes) from Najin and Fatu in delicate procedures. These eggs were then flown to Avantea, an Italian lab specializing in animal IVF, where they were matured and fertilized.
• Sperm Utilization: Frozen sperm from four deceased northern white rhino males—including Sudan and Suni—was used to fertilize the eggs.

Successful Embryo Creation

In 2019, the first two northern white rhino embryos were successfully created using Fatu’s eggs and Suni’s sperm. Since then, additional embryos have been produced, bringing the total to at least 30 viable embryos stored in liquid nitrogen.

Next Steps: Surrogate Mothers

The final challenge is implanting these embryos into surrogate southern white rhino females, a closely related subspecies. Southern white rhinos share enough genetic similarity to carry northern white rhino pregnancies, and several have been identified as potential surrogates.

• First Successful Pregnancy Attempt: In 2023, scientists achieved a milestone by successfully transferring a southern white rhino embryo into a surrogate, proving the technique’s feasibility. The next step is attempting the same with a northern white rhino embryo.
• Timeline for Birth: If successful, the first IVF northern white rhino calf could be born within the next few years.

Challenges and Ethical Considerations

Genetic Bottleneck

Even if IVF succeeds, the limited gene pool—derived from just a few individuals—poses long-term risks. Inbreeding depression could lead to health issues in future generations. To address this, scientists are exploring stem cell technology to create artificial gametes from preserved northern white rhino cells, potentially expanding genetic diversity.

Cost and Feasibility

The BioRescue Project has cost millions of dollars, raising ethical questions about resource allocation. Critics argue that funds could be better spent protecting other endangered species with larger remaining populations. However, proponents emphasize that saving the northern white rhino could advance conservation technologies benefiting other species.

Ecological Role of Rhinos

Rhinos are keystone species, shaping their ecosystems by grazing on grasses and creating water holes used by other animals. Their loss could disrupt African savanna ecosystems, making their restoration ecologically significant.

Broader Implications for Conservation

Lessons for Other Endangered Species

The techniques developed for northern white rhinos could be applied to other critically endangered species, such as the Sumatran rhino or the Javan rhino. IVF, stem cell reproduction, and genetic banking may become vital tools in preventing extinctions.

Public Awareness and Anti-Poaching Efforts

The plight of the northern white rhino has drawn global attention to the rhino poaching crisis. Increased awareness has led to stricter anti-poaching laws and stronger demand-reduction campaigns in Asia, where rhino horn is illegally traded.

Conclusion: A Race Against Time

The northern white rhino’s fate hangs in the balance, but scientific advancements offer a fighting chance. While challenges remain, the successful creation of IVF embryos marks a historic step toward reversing their extinction. If a northern white rhino calf is born via surrogate in the coming years, it could herald a new era in conservation—one where even the most critically endangered species have a shot at survival.

For now, the world watches and waits, hoping that science, perseverance, and a bit of luck will bring these majestic creatures back from the brink.

Key Takeaways:

• Only two northern white rhinos remain, both female.
• IVF has produced 30 viable embryos using eggs from Fatu and sperm from deceased males.
• Southern white rhino surrogates may carry the first IVF northern white rhino calf.
• Genetic diversity remains a challenge, with stem cell research offering potential solutions.
• Success could revolutionize conservation for other endangered species.

The story of the northern white rhino is a stark reminder of humanity’s impact on wildlife—but also a testament to our ability to innovate in the face of ecological crisis.