The Northern white rhinoceros (NWR) (Cermatotherium simum cottoni) is the rarest large mammal on earth. It is accepted that it is extinct in the wild and reduced to two surviving individuals in semi-captive conditions in Ol Pejeta, Kenya.
General consensus is that the NWR is a subspecies of the more numerous Southern white rhinoceros (SWR) (Cermatotherium simum simum) (Harley et al. 2016) . Using dental morphology and cranial anatomy Groves et al (ref) had described them as a separate Recent genetic studies (Moodley et al. (in prep)) found the two white rhino subspecies to have exchanged genetic material as recently as 100,000 years ago.
The NWR formerly ranged over parts of north-western Uganda, southern Chad, south-western Sudan, the eastern part of Central African Republic, and north-eastern Democratic Republic of the Congo (DRC). Poachers reduced their population from 2,200 to 15 through the 1960s and 1980s. Through in situ conservation initiatives in Garamba National Park the population recovered to more than 32 animals by 2003. However uncontrolled poaching as a result of the civil unrest in the DRC saw the wild population go extinct.
In January 2005, the Government of the DRC approved a two-part plan for the translocation of five Northern White Rhino from Garamba to a place of safety at the Ol Pejeta Conservancy in Kenya. Unfortunately, a last-minute political glitch put an end to this after all the infrastructure was in place.
In August 2005, ground and aerial surveys conducted under the direction of African Parks Foundation (who presently manage Garamba) and the African Rhino Specialist Group (AfRSG) only found four animals. A solitary adult male and a group of one adult male and two adult females. They have never been seen again.
Although SWR are commonly kept in zoos globally, in 2009 only zoo Dvur Kralove in the Czech Republic and San Diego Zoo in the USA held NWRs. In 2009 Zoo Dvur Kralove in the Czech Republic’s captive population comprised the following animals:
A male, “Sudan”, aged 32 years, who was in good health.
A male, “Suni”, aged 18 years, who was in good health.
A female, “Najin”, aged 18 years, also in good health. Najin is Sudan’s daughter.
A female “Fatu”, 8 years old and in good health.
A female, “Nabire”, aged 25 years. She never bred as she had cystic ovaries.
An elderly female with locomotor problems not suitable for relocation.
In 2009 the San Diego Wild Animal Park in the USA had two Northern White Rhinos, a female “Nola” and a male “Angalifu”, who were wild-caught. They were too old to breed. A massive effort was made between the San Diego Wild Animal Park and the Czech Republic to get as much as possible of Angalifu's semen to the female rhinos in captivity. However, this did not result in success.
With the failure of numerous artificial breeding attempts, Zoo Dvur Králove requested Back to Africa to investigate a free-ranging venue in Africa to enhance the breeding potential of these rhinos.
A meeting was held at Dvur Kralove in 2008 to discuss the matter of moving the rhinos to Africa. There were many expert delegates including members of the IUCN African Rhino Specialist Group (AfRSG). Most agreed it was the right decision to move the animals to Africa. However, it must be pointed out that the EAZA studbook keeper for white rhino at the time Mr Lars Versteegte did not support the move. This, created some rancour when the decision was made to move them to Africa which took place on the 20th December 2009.
HOW IMPORTANT IS TO SAVE THE NORTHERN WHITE RHINO?
With the morphological differences between the two subspecies being so small there has been debate as to how important it is to save the NWR. Would the effort be a wise use of limited resources?
Could SWRs not fill the same ecological niche? Do these animals carry genes that are important to preserve?
With only four potentially fertile animals left on earth, was there sufficient genetic material to perpetuate the NWRs?
Should the achievement of a pregnancy of a pure NWR be the primary objective or should perpetuation of their genes in the form of inter-crosses as advised by the IUCN AfRSG be the route to follow. This became a point of contention in the project.
RATIONALE TO MOVE THE REMAINING NWRS TO AFRICA
Southern white rhinos breed well in natural conditions and conservationists in Southern Africa and Kenya regard it as unusual to see a female without a calf at foot. As a result of over-exploitation, SWRs were reduced to less than a hundred animals in 1890s. However, through protection, good management and sustainable use, their population has increased to 20 000 (Knight 2015). As part of this species recovery an extralimital population of 58 SWRs were introduced to Kenya between 1965 and 1994 and they now number close to 400.
They historically have not breed well in zoos with pregnancies in captive SWRs being perceived as a major event – although it is improving (Versteege, 2012) Artificial reproduction techniques have often been used effectively to achieve these and this technology evolved due to the poor breeding performance of white rhinos in zoos.
As at the time, white rhino did not breed well in zoos, there was a dilemma: Go the artificial route in the zoo, or allow nature to do its work naturally.
One must not forget the Northern Whites in Dvur Kralove were repeatedly manipulated by European reproductive experts without success. Pregnancies had not been achieved and such artificial manipulations can interfere with natural reproductive potential.
This work however confirmed they were potentially fertile at the time of moving to Africa..
Prolonged reproductive inactivity often leads to degeneration of female reproductive tracts as result of cervical leiomyomas (tumours) and tubular obstruction. Time was running out.
Moving the animals to Africa seemed the logical, responsible thing to do. It was logical therefore that after many visits to Africa where the breeding success of wild white rhinos clear to see the Dvur Kralove staff decided to pursue a more holistic approach.
At the time of moving the Dvur Kralove NWRs to Kenya there had been unconfirmed reports of rhinos existing in Southern Sudan in the Sud swamp (ref..). This is a vast area and is politically unstable making it awkward to achieve effective surveillance. Fauna and Flora International (FFI) became involved in Southern Sudan and Matt Rice of FFI was residing in the area had attempted to locate these stragglers. Plans were afoot to get cooperation from the Sudanese authorities to catch them and move them to a safe haven for their protection.
If indeed there were animals there and the genes of these animals could participate in the breeding project then there was a chance the NWR could be saved. There was a better chance of moving animals from Sudan to elsewhere in Africa than exporting them to Europe and this was another factor which mitigated in favour of moving the zoo animals to Kenya. Unfortunately, the stability of the region deteriorated progressively so the chance of finding and using these animals became less and less likely.
In summary there were four live fertile animals, possibly additional animals in southern Sudan, stored semen, stored tissue samples that could be used to produce gametes using stem cell technology.
There was a chance that the NWR could be saved.
CHOICE OF SITE
Hamish Currie took the then-zoo director of Zoo Dvur Kralove, Dana Holeckova to Africa to investigate potential sites. The first site visited was the farm Rooipoort in the Kimberley area of the Northern Cape Province of South Africa. This belongs to Oppenheimer family who are considerably involved in conservation projects in South Africa. Ol Pejeta Conservancy in Kenya was also investigated on the advice of world renowned rhino conservator Mr Ian Craig. This latter site was selected for the NWR project.
On the 20th December 2009 the four last fertile NWRs in the world (Sudan, Suni, Najin and Fatu) touched down at Jomo Kenyatta Airport, Nairobi from Prague in a Martinair 747 cargo aircraft. Accompanying them on their flight was Back to Africa director and veterinarian Dr Peter Morkel.
Indeed natural conditions did change their behaviour, cycling was noted, mating was observed but sadly a pregnancy was never achieved. The project was done in partnership with FFI under the direction of Dr Rob Brett and of course with Ol Pejeta conservancy and Kenya Wildlife Services. A move is now underway with reproductive experts from the Berlin Institute led by Professor Thomas Hilderbrandt to harvest ova from the last remaining females , mother and daughter Najin and Fatu . Using frozen semen the eggs will be fertilized producing embryos that will be implanted into SWR females. Pure NWR could be produced in this manner. To this end Prof Hilderbrandt and his team have been collecting ova from SWR in European zoos and refining their technique. On the 22nd August 2019 Prof Hilderbrand and his team successfully harvested 5 ova from each female. These were flown by helicopter to Nairobi and then flown to Italy where they were matured. Using frozen sperm two embryo’s have been produced have been stored for eventual implantation into surrogate southern white rhino cows.Concurrent efforts are underway in South Africa with Dr Morne de la Rey having developed his own technology to do ovum pick up. He is working in collaboration with the San Diego Zoo who are using stem cell technology to produce ova.