Monday April 14, 2025
Ol Pejeta, Kenya

The grass at the foot of Mount Kenya looks delicious. The two female rhinoceroses feast quietly on it, indifferent to the immense global effort underway to prevent their species from dying out with them.
Najin and her daughter Fatu are the last two surviving northern white rhinos, an African subspecies that could soon join the list of animals that humans have poached to extinction.
But thanks to a recent scientific breakthrough, an embryonic northern white rhino could be growing by 2025. A development that would be spectacular for this sub-species declared technically extinct after the death of its last male, Sudan, in 2018.
Neither Najin nor Fatu, Sudan’s daughter and granddaughter respectively, can carry a pregnancy to term due to uterine problems.
But Fatu still produces viable eggs, which could be sown in in vitro fertilization (IVF).
For several years, scientists have been collecting her eggs in the Ol Pejeta private game reserve in central Kenya, where the two females live under 24-hour surveillance.
The eggs are sent to Europe where, in a laboratory, they are fertilized with sperm from various deceased males.

Researchers have now obtained 36 fertilized eggs – or embryos – ready for implantation, says Jan Stejskal, project coordinator for BioRescue, the world’s largest initiative to resurrect the species.
These experts believe that Fatu can still produce around ten more eggs.
“We hope to achieve the first successful pregnancy with a northern white rhino embryo this year,” says Stejskal.
“But I can’t promise it.”

– “Joy and sadness” –
The idea is to use a female southern white rhino, a closely related species, as a surrogate mother.
A year ago, scientists had announced a breakthrough: the first IVF had been successfully performed on a surrogate mother – but with a southern white rhino embryo.
And, like many steps in this long and difficult process, joy was soon “mixed with sadness”, points out Samuel Mutisya, Ol Pejeta’s research director
. After around two months, the surrogate mother died of an infection unrelated to her pregnancy.

The team is determined to try again, this time with a northern white rhino embryo.
There are other avenues. In Japan, researchers are attempting to use stem cells to create male and female gametes.
If successful, this would radically increase both the number of embryos and genetic diversity for future IVF.
According to Stejskal, this research is about halfway through, and embryos could be produced in around 4 years’ time.
Meanwhile, Oxford University is attempting to use ovarian tissue from deceased female rhinos to create new eggs. Even after the death of Najin, 35, and Fatu, 24, scientists could then exploit the immature eggs in their ovaries.
Suzannah Williams, who leads the initiative, estimates that a few hundred eggs could be recovered “at best”, although not all would be viable.
The ideal scenario would be for a new baby to be born while Najin and Fatu are still alive, to teach it how to behave as a northern white rhino.
– Too late –
Nobody knows exactly what the chances are of a single IVF attempt resulting in pregnancy. It took three a year ago.
Many other stages could come to nothing in a gestation period lasting 18 months.
But Mr Stejskal remains optimistic: “We’ll save them”, he says, while Ms Williams believes the question is “when, not if”.

Many other stages in the 18-month gestation period could come to a halt.
But Mr Stejskal remains optimistic: “We’ll save them”, he says, while Ms Williams believes it’s a question of “when, not if”.
Others are less convinced.
Even if babies were to be born, genetic diversity would be “too low” to revive the subspecies, Jo Shaw, director of the NGO Save the Rhino International, told AFP.
It’s probably already too late for the northern white rhinos, she says, and attention should instead be focused on the Java and Sumatran subspecies, which each number fewer than 50 individuals.
But researchers working on the northern white rhino stress that the techniques they are developing will help all these behemoths, as well as other species. BioRescue’s work is already helping to save the Sumatran rhino,” says Stejskal.
In their Ol Pejeta enclosure, Najin and Fatu’s main carer, Zacharia Mutai, argues that humans are responsible for their extinction, and therefore for their resurrection.
Mr. Mutai, who also knew Sudan, believes that the birth of a baby would be “celebrated worldwide.”
“And I’ll look after the baby,” he adds with a smile, while behind him Fatu and Najin continue to feast on grass.

Humaniterre with AFP