When Josef Vágner, head of the Dvůr Kralové Zoo, brought six Northern White Rhinos back from a trip to Sudan in the early 1970s he was criticized by the public for taking them from the wild. Now the zoo that he set up and the herd that was successfully bred there over the years may help to save the species that has been wiped off the face of the Earth by poachers. There are now three Northern White Rhinos left on the planet and all three belong to Dvůr Kralové Zoo and reside in a heavily guarded nature reserve in Kenya. Last week came the news that the last male was close to death due to a life-threatening infection. I asked Jan Stejskal head of the zoo’s special projects, to tell me how Sudan is faring at present.
“Sudan resides in the Ol Pejeta Conservancy in Kenya where he was transported in 2009 together with other at-the-time fertile Northern White Rhinos and we got news last week that his health had deteriorated significantly. He is taken care of by many veterinarians from Kenya and we consult his health with other leading vets from around the world. It now seems that the infection in his leg which gave cause for alarm is slightly better, but to be honest he is 45 which is quite an age for a rhino, so we have to accept that, given his age and health problems, we will have to think about euthanasia in the foreseeable future.”
Is this a death knell for the breed then? How many are left and what condition are they in?
“Actually, it may sound unbelievable, but even if Sudan died there would still be a chance that he could have offspring. There are two females that live in Ol Pejeta with him and we will try to harvest oocytes from these females and fertilize them in a laboratory in Europe. We would perform in vitro fertilization that would produce an embryo that would later be put into a surrogate mother – for this purpose we have frozen semen and we even have frozen semen from Sudan. So at some point in the future Sudan could still have offspring.”
So you have frozen semen from a number of Northern White Rhinos which could still help save the breed?
“Exactly, we from Dvůr Kralové Zoo, together with our partners in San Diego Zoo and in Berlin, have frozen semen from five bulls – it is not clear if the semen from all these bulls could be used for fertilization efforts but we are convinced that semen from at least four of them would be suitable.”
And what about the last two females –what condition are they in?
“They are fine. I saw them a few weeks ago and they were doing well. Najin is twenty-eight now and Fatu is eighteen, so it is quite a good age still for them to cycle. We conducted health checks on them in 2014 and we found that although they cannot reproduce naturally they still cycle and they produce oocytes. We assume that nothing has changed since and are hoping to harvest quite a good number of oocytes from them when we go there.”
So what are the possibilities?
“During the last two years we developed new techniques in Europe that would help us perform IVF. Together with our partners from Berlin and Cremona we developed techniques how to harvest oocytes and how to create an embryo. So in the coming months – I cannot say exactly when because we are still waiting for permits needed for transport of genetic material – we will go to Ol Pejeta for a first-ever attempt to harvest oocytes from Northern White Rhino females. That would be a major breakthrough in the project to save the Northern White Rhino through artificial reproduction techniques.”
If you manage to do that, then genetically you would have a Northern White Rhino but it would have to be carried by a Southern White Rhino female – is that correct?
“That’s right. The embryo would be “pure” Northern White Rhino but it would have to be carried by a Southern White Rhino female and we have surrogate mothers already prepared in Ol Pejeta.”
Has this proved successful with other breeds? Would a Southern White Rhino mother accept a Northern White Rhino baby?
“That’s a question we don’t know the answer to, because it has never been done before. But we assume that we could somehow overcome an immunity response in the mother if a problem should arise. But we will not know that until we try it. So yes, there may be some problems with the body of the female Southern White Rhino accepting a Northern White Rhino embryo, but we will see.”
When can we expect the first such calf to arrive – if you are successful?
“I get that question very often, but I really cannot say when we will succeed. This is cutting-edge science and it is really difficult to predict what obstacles we may meet on the way. So it is really hard to give you an answer. Even with human IVF and even in IVF with cattle and horses it took a number of trials before it was successful. We have to expect the same situation with Northern White Rhinos, so I really cannot say.”
If the Southern White Rhino mother were to reject the embryo – is that the end of the road for the Northern White Rhino?
“I think we would overcome that. There are various ways. For example, to put it simply, the outside layer of the cell that would be put into a surrogate mother would be that of a Southern White Rhino. These are options that we could explore.”
How long would it take to gradually bring them back?
“The ultimate aim of the whole project is to return Northern White Rhinos back to their natural habitat, but even if all goes well and we overcome all the hurdles on the way, I would not expect that to happen earlier than in, say, fifty years.”
How large a herd are we talking about?
“That is really far away. First you have to have babies and create a small population – ideally in Ol Pejeta but it would also be wise to create a small population in European zoos and maybe San Diego in the US. And only after you have this controlled population you can choose the right specimens to be introduced to their original habitat. And of course it would have to be a secure habitat in their original range, so we are talking about five animals, ten animals, we would see how many there would be and what would be the situation in 50 years’ time.”
Would they ever really be released into the wild? We don’t even know what the natural environment would be like in 50 years’time…
“Yes, it’s difficult to predict, but in any case, as is the case with all animals bred in captivity or semi-captivity after translocation they are always kept in some fenced area for a while because they need to adapt to the new environment. So definitely in the beginning they would be in some fenced-off area and we would have to carefully observe them and their reaction to their new surroundings.”
Are there any Northern White Rhinos left at Dvůr Kralové Zoo?
“No, no, these three that are in Ol Pejeta are the last Northern White Rhinos in the World. The last one that was left in Dvůr Kralové Zoo was the female Nabire - Sudan’s daughter actually – she died in July of 2015 and the last Northern White Rhino in North America was Nola, she was also transported there from Dvůr Kralové Zoo – she died in November 2015. So ever since there are only three Northern White Rhinos left. All belong to Dvůr Kralové Zoo and all of them reside in Ol Pejeta in Kenya.”
Would you say this is a life project for you? What are you hoping to achieve in your lifetime?
“It is difficult to say whether it is the most important project, because I am also working on other projects related to the conservation of rhinos. For example in the case of black rhinos we are not in so desperate a situation as in the case of the Northern White Rhino, and we may be more successful. What I would really like to see in my lifetime regarding Northern White Rhinos is to see them returned to their original habitat. I would be extremely happy and I would regard it as an outstanding success in conservation.”