NAIROBI, Kenya (AP) — A rhinoceros has been impregnated through embryo transfer. This was the first successful use of a method that conservationists say could later make it possible to save the nearly extinct subspecies of northern white rhinoceros.

In tests on a different subspecies, researchers created a southern white rhino embryo in a laboratory from an egg and sperm previously collected from other rhinos and transferred it into a southern white rhino surrogate mother at the Ol-Pejeta Conservancy in Kenya.

“The successful embryo transfer and pregnancy is a proof of concept and allows (researchers) to now safely proceed with the transfer of northern white rhinoceros embryos – a cornerstone in the mission to save the northern white rhinoceros from extinction,” the group said in a statement statement Wednesday.

However, the team only found out about the pregnancy after the surrogate mother died of a bacterial infection in November 2023. The rhino was infected when spores of the Clostridium strain were released from the soil by flooding, and the embryo was discovered during a post-mortem examination.

Nevertheless, scientists are very optimistic about their results.

“Now we have clear evidence that an embryo frozen, thawed and produced in a test tube can give rise to new life, and that is what we want for the northern white rhinoceros,” is Professor Thomas Hildebrandt, lead researcher and director the reproduction department at BioRescue.

About 20,000 southern white rhinos still live in Africa. This subspecies, as well as another species, the black rhinoceros, are recovering from significant declines in their populations due to poaching for their horns.

However, there are only two known representatives of the northern white rhinoceros subspecies worldwide.

34-year-old Najin and her 23-year-old offspring Fatu are both incapable of natural reproduction, according to the Ol-Pejeta Conservancy where they live.

The last male white rhino, Sudan, was 45 years old when he was euthanized in 2018 due to age-related complications. He was Najin’s father.

Scientists stored his sperm and that of four other dead rhinos in hopes of using them for in vitro fertilization with eggs from female northern white rhinos to create embryos that will eventually be carried by southern white rhino surrogate mothers.

Some conservation groups have argued that it is probably too late to save the northern white rhino through in vitro fertilization, as the species’ natural habitat in Chad, Sudan, Uganda, Congo and the Central African Republic is being destroyed by human conflict became. Skeptics say efforts should focus on other endangered species with better chances of survival.

___

Corrects previous version of this story that said the pregnant rhino was alive and expected to give birth late next year.

___

Follow AP’s Africa coverage at https://apnews.com/hub/africa