One of the World's Last Two Northern White Rhinos Retires From Breeding Project Due to Old Age, Illness

The last male northern white rhino named Sudan died in 2018, leaving only two female white rhinos. Scientists hoped that hybrid embryos will save the species from extinction through a world-first breeding project.

However, scientists in Africa recently announced that Najin, the older of the two northern white rhinos, is retiring as an egg cell donor in the breeding program aimed to save their species. Doctors found that the white rhino is impacted by her old age and illness. Now, only her daughter Fatu is left in the program.

Najin, Retiring as Egg Cell Donor

BioRescue, the consortium assigned to the breeding program of the world's last two northern white rhinos, said in a statement that the team decided to retire 32-year-old Najin as a donor of egg cells after an in-depth risk assessment. It left the ambitious breeding program with just one female egg cell donor.

According to the Daily Mail, researchers pointed out Najin's old age and signs of illness have pushed them to make that decision. Doctors have found "multiple, small benign tumors in her cervix and uterus, as well as a 25-centimeter cyst in her left ovary."

They concluded that these two factors may have been the reason egg cell collections with her were not as successful as her daughter's. That is why they made up their mind that the most suitable role for Najin would be as an ambassador for the conservation of her species and to ensure her social knowledge and behavior will be passed to the next generation.

After Sudan died in 2018, there are no known living male white rhinos that scientists have found. More so, neither of the world's last two northern white rhinos can carry a calf to term.

World-First Breeding Program for White Rhinos

BioRescue project head Prof Thomas Hildebrandt said in the statement that every procedure of the breeding program involves a full ethical risk assessment and that retiring Najin is the best decision. They believe that developing clear ethical principles based on their knowledge, scientific expertise in animal welfare ethics and decision making is a fundamental basis of BioRescue.

The BioRescue team from the Leibniz Institute for Zoo and Wildlife Research in Germany is raising against time to save the northern white rhinos species, the world's most endangered mammal.

The first batch of embryos they created was in 2019, and since then, they have collected 80 eggs from both Najin and Fatu. But the all viable embryos all came from Fatu. According to Phys.org, the team of scientists has created more embryos in July this year, bringing the total to 12 viable embryos.

The team hopes to deliver its first northern white rhino calf in three years, and perhaps create a wider population in the next two decades. The embryos will be placed into surrogate mothers, most likely southern white rhinos.

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