Kenyan Northern White Rhino Najin Retired from the Breeding Scheme

By Lauren Chalouhi, Staff Reporter, The Pawprint

Scientists have stepped back from one of the world’s last two northern white rhinos from a breeding program to try to save the species from going extinct.

This decision to stop harvesting the 32-year-old Njin’s eggs was followed by an “ethical risk assessment” which considered her age and many other factors. Both Najin and her daughter Fatu are unable to carry a rhino calf to term. The last male rhino of the species died back in 2018, but they collected his sperm and it has been used to try to fertilize eggs.

The procedure involves a team of vets who extracted the rhino’s eggs, using techniques they developed through many years of research. The eggs are then sent to an Italian lab for fertilization, using the sperm they harvested from the two deceased male rhinos. 

Twelve embryos have been created so far, and scientists have high hopes that these embryos will be successful and be born through surrogate mother rhinos selected from a population of southern white rhinos.

The scientific group leading the program, ‘BioRescue,’ said that it has weighed up several risks before deciding to put an end to harvesting Najin’s eggs. The head veterinarians, Frank Göritz and Stephen Ngulu said that “retiring one individual from a conservation program because of animal welfare considerations is usually not a question to think about for long… but when one individual is 50 percent of your population, you consider this decision several times.” 

Because of Najin’s age, the ultrasound scans revealed many small benign tumors on her cervix as well as her uterus and a cyst on her left ovary. However, BioRescue said that Najin would remain part of the program in other ways, by providing tissue samples for further stem cell research.

Scientists hope that she can also “transfer her social knowledge and behavior” to future offspring. Northern white rhinos have been brought to the edge of extinction because of poachers and loss of habitat. Najin was born in a Czech zoo but was then moved a decade later to ‘Ol Pejeta Conservancy in Kenya,’ she has been living under armed protection there since.