In a groundbreaking effort to save the Northern White Rhino from the brink of extinction, scientists have embarked on an ambitious mission—implanting lab-created embryos into surrogate rhinos in hopes of reviving the species.
With only two females left in the world, this high-stakes project at Kenya’s Ol Pejeta Conservancy is pushing the boundaries of reproductive technology. As poaching and habitat loss have driven these majestic creatures to near oblivion, conservationists are now racing against time, harnessing cutting-edge science to give the species a second chance.
The process involves preparing a Southern white rhino surrogate mother to carry an already fertilised egg belonging to their close relatives- the Northern White rhinos to term.
The use of vitro fertilisation and exploring surrogacy has been used for seven years now.
In the latest procedure that was undertaken at the close of February 2025, the researchers undertook a sterility check on 'Jomo', a Southern White Rhino teaser bull.
The bull's role in the process is to detect whether the female surrogate Southern White Rhinos is ready for the embryo transfer.
“Ensuring his sterility is imperative to prevent the risk of impregnation of the Southern White Rhino surrogate females during the surrogacy process,” Bio Rescue team noted in a statement.
The researchers have also been preparing Daly, one of the selected surrogate mothers where they conducted a pregnancy test.
“A pregnancy check was conducted to confirm her status and suitability as an ideal candidate for carrying a Northern White Rhino embryo to term," researchers noted.
"For the assisted reproduction to succeed, it is essential that the surrogate mother is not already pregnant and the reproductive tract is healthy so as to ensure she can safely carry a Northern White Rhino embryo,” they further noted.
In March 2018, the last male Northern White Rhino, Sudan, died, dealing a blow to conservation efforts.
Sudan left behind Najin and daughter Fatu, who have reproductive challenges and hence cannot carry pregnancies to term. Najin, has however been retired from the process of oocyte collection as a result of her old age.
The death of Sudan revealed the vulnerability of the sub-species, unearthing the poaching crisis of the 1970s and 80s.
Poaching is fueled by the demand for rhino horn in Traditional Chinese Medicine in Asia and dagger handles in Yemen that wiped out the northern white rhino populations in Uganda, Central African Republic, Sudan and Chad.
In 2019, a consortium of scientists and researchers started exploring advanced Assisted Reproductive Technologies (ART), including IVF to rescue this subspecies given the condition of the two females.
The Biorescue team has since been undertaking the procedures in phases.
In the initial phases, researchers collected the immature eggs (oocytes) from the only two surviving female rhinos in Ol Pejeta and immediately transported them to Avantea laboratory.
At the laboratory, the eggs are matured and fertilised with the semen collected from northern white rhino males before they die.
Once the embryos are developed, they are stored in liquid nitrogen.
As of February 2024, scientists had created 30 northern white rhino embryos through in vitro fertilization, which are stored in laboratories in Berlin and Cremona, Italy.
They are awaiting transfers to the surrogate mothers, the northern white rhino species, who will carry pregnancy to term.
One of the remaining two females known as Najin, has since retired from the process of oocyte collection as a result of her old age.
Although the northern white rhinos did not exist in Kenya historically, they were introduced in the country in 2009 when the world’s last four potential breeding rhinos were in captivity in a zoo in the Czech Republic.
They were later moved to Ol Pejeta Conservancy, with hope that the wild conditions would stimulate them to breed.
However, this did not, a crisis further exacerbated by the death of Suni and Angalifu in October 2014.
In 2022, researchers announced a breakthrough after successfully fertilising eleven eggs from semen that were collected way back.
The semen was collected from Suni, who died aged 34 in 2014 and Angalifu, who died in December the same year.
Before the male northern white rhinos, including the last one, Sudan, who died in 2018, researchers harvested semen and kept them in laboratories.
The last of northern white rhino subspecies were wiped out at Garamba National Park in the Democratic Republic of the Congo during the 1990s and early 2000s.
By 2008, the northern white rhino was considered by most experts to be extinct in the wild.
Through collaborative efforts, conservation stakeholders and researchers came together through Biorescue Consortium, which brings together Kenya Wildlife Service, the Leibniz Institute for Zoo and Wildlife Research-Berlin, Safari Park Dvůr Králové-Czech Republic, the Wildlife Research and Training Institute-Kenya.
Avantea Laboratories-Italy, Padua University-Italy, Max Delbbruck Centre for Molecular Medicine (MDC), Kyushu University-Japan and Ol Pejeta Conservancy, among other partners.