Czech and international experts looking to surrogacy to save virtually extinct northern white rhino

Officials from Dvůr Králové zoo and other international organisations have announced fresh progress in efforts to save the northern white rhino, of which only two remain alive. They have now created a third embryo that would be carried by another subspecies and the next step will be to identify suitable surrogates. I spoke to Dvůr Králové’s Jan Stejskal, who is coordinating efforts to preserve the northern white rhino.

Najin and Fatu are the last two northern white rhinos on the planet|Photo: Ami Vitale

“We did health checks on the last two, female northern white rhinos in Ol Pejeta [Kenya] and we found that they are not capable of natural reproduction.

“So the only way for them to have offspring is through advanced techniques of artificial reproduction.

“We needed to develop techniques for this.

“There is a group of co-operators – Dvůr Králové zoo, IZW Berlin, Avantea Laboratory in Italy, Ol Pejeta Conservancy in Kenya and the Kenya Wildlife Service – and during these years we developed a technique to harvest eggs from these females and to fertilise them with semen, from males that already deceased, that is frozen, and after fertilisation to produce an embryo.

“The task is that we need to get the embryo into a stage when we can freeze it.

“Because only frozen can we get it to somewhere.

“If we, for example, want to put it into a surrogate mother of southern white rhino origins in Kenya, then the only way to get the embryo there is to have it frozen.”

How difficult is this process?

Jan Stejskal checks on Fatu, the youngest of the two northern white rhinos on the planet the day before the procedure on Ol Pejeta Conservancy|Photo: Ami Vitale

“So far we have achieved embryos, and that’s a crucial step on our way.

“But of course in front of us is embryo transfer into a surrogate mother, because none of these northern white rhino females are capable of reproduction.

“So we have to find the right southern white rhino females.

“And we still have to optimise the technique for transfer.

“Actually the technique was already used in European zoos, but we have not so far achieved a successful pregnancy.

“We already did these procedures with embryos that were produced from southern white rhino eggs.”

When you select the surrogate southern white rhinos to carry the embryos, what qualities will they need to have?

“You try to find a female that is in the best age, which, let’s say, could be around 10 years of age.

“Ideally she would have already given birth in the past, because it means she would be a proven breeder.

“We also need to have this female in relatively controlled conditions, which means it shouldn’t be a female that is roaming free.

“In Ol Pejeta there is a very, very large enclosure for endangered species and there are already five southern white rhino females there.

“So we believe that at least one of these females will be suitable for the purposes of surrogacy.”

How optimistic are you that this surrogacy will work and ultimately help save the species?

Dr. Susanne Holtze from Leibniz-IZW, Prof. Dr. Thomas Hildebrandt from Leibniz-IZW and Prof. Cesare Galli, are searching for oocytes, photo: Ami Vitale

“We have to admit that there are still chances that we would fail.

“On the other hand, when we found out five years ago that the northern white females cannot naturally breed we didn’t know how to collect eggs.

“We didn’t know at that time exactly how to produce an embryo.

“So something has been achieved during the course of the years.

“And I think these achievements could make us a little bit optimistic that we would be able to overcome even the obstacles that might be in front of us.

“But definitely it will take years before we would be happy to see a northern white rhino calf being born.”