The Female Northern White Rhino Will Never Have Calves Again. Only Two of This Subspecies Remain in the World

Scientists have managed to create 12 embryos, which they plan to implant into surrogate mothers.

Scientists have removed from the breeding program a female northern white rhino, of which only two remain in the world. The decision to stop collecting eggs from 32-year-old Najin was made after an “ethical risk assessment” that took into account her age and other indicators. 

Neither Najin nor her daughter Fatu is able to carry a rhino calf. The last male of this species died in 2018, but his sperm was collected and used to fertilize eggs. During this procedure, a team of veterinarians retrieves a rhino egg using methods developed over years of research. 

The eggs are then sent to a laboratory in Italy, where they are fertilized with the sperm of two deceased males. To date, scientists have created 12 embryos, which they hope to implant into surrogate mothers selected from the southern white rhino population. 

The BioRescue research group, which manages this scheme, said that after weighing the risks they decided to stop collecting eggs from Najin. Chief veterinarians Frank Göritz and Stephen Ngulu noted: “Removing one individual from a conservation program for the sake of animal welfare is usually not a problem, but when one individual makes up 50% of the entire population, you think about it more than once.” 

In addition to the female rhino’s advanced age, ultrasound scans revealed several small benign tumors on and inside the cervix, as well as a cyst on the left ovary. However, the team of scientists said Najin remains a participant in other aspects of the program. 

They take tissue samples from her for stem cell research. There is hope that she will also be able to “pass on her social knowledge and behavior” to future offspring. 

Poaching and loss of habitat drove the northern white rhino to the brink of extinction. Najin was born in a Czech zoo, but decades later she was moved to the Ol Pejeta Conservancy in Kenya, where she lives under armed protection. 

The last northern white rhino male in the world died after months of illness. 45-year-old Sudan lived in Kenya at the Ol Pejeta Conservancy. He died from complications related to age. Without a male, the only two females in the world, his daughter and granddaughter, are left. 

All hope for preserving the northern white rhino species lies in developing artificial insemination methods. However, attempts to use Sudan to continue the species with the two females have failed. 

A profile was even created for him on the dating app Tinder, not to find love, but to raise funds for artificial insemination of rhinos. Sudan had fans around the world who have missed him for several years, and because of the approaching extinction of the subspecies (the northern white rhino is one of two subspecies of white rhino). 

Sudan’s genetic material was collected, so scientists have tried to recreate northern rhinos using advanced cell technologies, using the preserved sperm and eggs of females Najin and Fatu. 

In human years, the male was 90 years old. He was treated for degenerative changes in muscles and bones, as well as large skin wounds. Sudan could not stand on his own legs and suffered greatly during the last day of his life.