Northern White Rhino Functionally Extinct, Two Females Remain.
The northern white rhinoceros (Ceratotherium simum cottoni) was declared functionally extinct following the death of the last male, Sudan, on March 19, 2018, at the Ol Pejeta Conservancy in Kenya. Only two females, Najin, 35, and her daughter Fatu, 24, survive, both unable to reproduce naturally due to health issues, making population recovery through natural means impossible.
Once widespread across Uganda, Chad, Sudan, the Central African Republic, and the Democratic Republic of Congo, the subspecies numbered over 2,000 in the 1960s. Poaching for their horns, fueled by demand for unproven medicinal uses and ornamental value, combined with habitat loss and regional conflicts, reduced their population to 15 by the 1980s. By 2008, northern white rhinos were extinct in the wild. Sudan, Najin, and Fatu were moved from a Czech zoo to Ol Pejeta in 2009, but breeding attempts failed.
Najin and Fatu, now under constant armed guard at Ol Pejeta to deter poachers, cannot carry pregnancies. Najin has weak hind legs, and Fatu has uterine complications. The subspecies’ genetic diversity was further diminished by a historical bottleneck, limiting resilience.
The BioRescue consortium has developed 36 embryos using Fatu’s eggs and sperm from deceased males, including Sudan, for implantation into southern white rhino surrogates, a subspecies with over 15,000 individuals. A 2024 trial successfully implanted a southern white rhino embryo, but the surrogate died at 70 days from an unrelated bacterial infection. Scientists aim for a northern white rhino embryo implantation by late 2025. Other efforts include stem cell research to generate eggs and sperm and Oxford University’s work to harvest eggs from deceased rhinos’ ovaries.
Conservationists, including Jo Shaw of Save the Rhino International, caution that the limited genetic pool may prevent a viable population, even with successful embryo transfers. Attention is also shifting to protect other critically endangered rhinos, like the Javan and Sumatran, each with fewer than 50 individuals. The northern white rhino’s decline highlights the critical need for stronger anti-poaching and habitat conservation measures.