The northern white rhino once occurred in southern Chad, the Central African Republic, southwestern Sudan, northern Democratic Republic of the Congo (DRC), and northwestern Uganda. As recently as 1960, there were more than 2,000 remaining.
However, poaching has led to their extinction in the wild. And now there are only 2 individuals left on earth - both of them in captivity. The future for this subspecies is very bleak.
The Story of the Northern Whites:
On December 20th, 2009, four of the world’s last remaining seven northern white rhinos were transported to Ol Pejeta conservancy in Kenya. Najin, Fatu, Sudan and Suni had been living in Dvur Kralove Zoo in the Czech Republic. Previous attempts of breeding the rhinos in the zoo did not go as planned hence the transfer to a more conducive habitat in Ol Pejeta with the hope that it would provide them with more favourable breeding conditions.
With breeding attempts being unsuccessful in the conservancy, it was decided that a southern white male would be introduced to Fatu and Najin in the hope of producing offspring that would at least preserve some of the northern white genes. Again, this proved unsuccessful.
In October 2014, Suni passed on in his enclosure out of natural causes. His death left Sudan as the only northern white male in the world capable of breeding. In early 2015, checks by vets from the Czech Republic showed neither of the females were capable of natural reproduction, and Sudan’s sperm count was disappointingly low (but not surprising given his age). In July 2015, Dvur Kralove Zoo in the Czech Republic lost Nabire, and in November 2015, San Diego Zoo lost Nola - leaving just three northern white rhinos left on the planet.
On the 19th of March, 2018, Sudan died. He had been suffering from age-related health issues and from a series of infections. Once his condition worsened significantly and he was unable to stand up and evidently, suffered a great deal, the decision to euthanise him was made by his veterinary team. Good news!
The vet checks did conclude one last ray of hope – that artificially assisted reproduction was a possibility. The future of this subspecies now lies in the development of in vitro fertilization techniques and stem cell technology, costly and complicated procedures that have never before been attempted in rhinos.
Progress so far
Fast forward to 2019 experts from the Avantea laboratory in Italy in conjunction with Ol pejeta conservancy began working on the IVF process. Sperms collected from male northern white rhinos had been frozen. All the scientists needed to do was harvest eggs from the last two females. A lengthy and complicated process which had never been tried before. This approach may, if it is successful yield several births of northern white rhino calves but it has limits. First, the egg collection is a complicated procedure and can only be conducted three times a year so the number of natural gametes and therefore possible attempts is limited. Second the genetic variability is limited as the sperms and eggs come from a small number of individuals. To add onto the complications a surrogate mother from the southern white rhino also needed to be found since Najin and Fatu are unable to carry a pregnancy.
In August 22nd 2019 the team of scientists started the process of egg harvesting. A probe guided by ultrasound was inserted into the rhino’s uterus. 10 eggs were harvested in total later on an announcement was made that 7 out of the 10 eggs (4 from Fatu and 3 from Najin ) were successfully matured and inseminated with the frozen sperm from 2 white rhino bulls. The scientists later stated that three eggs had developed into a blastocyst (early embryo) stage. This therefore means that now a southern white rhino surrogate can be identified to carry the embryo.
This in itself is a big achievement as it is the first time that scientists have been able to produce embryos for Northern white rhinos using the IVF process. Other IVF procedures have been performed on Najin and Fatu and now there are 5 viable embryos which are all stored in liquid nitrogen awaiting a surrogate mother.
Am sure having real all that you might be thinking “Why go through all this to save one species”.
Well, we are the sole cause of to their close extinction. Think about it as compensation for the poaching of rhinos. The northern white rhinos represent the last known individuals of an important megafauna of central Africa and so contain valuable genes that must be preserved. Equally rhinos provide a unique bio service to other communities such as small antelopes, birds, insects and bats. Some of these bio services cannot be comprehended and they are better off alive than dead
White rhinos are the second largest land mammal after the elephant. Adult males can reach 1.85m in height and tip the scales at a massive 3.6 tonnes. Females are considerably smaller but can still weigh in at an impressive 1.7 tonnes. White rhinos are also known as the square-lipped rhinoceros due to their square (not pointed) upper lip. Their name comes from the Afrikaans word “weit”, which means wide and refers to the animal’s muzzle. Compared to black rhinos, white rhinos have a longer skull, a less sharply defined forehead and a more pronounced shoulder hump. They have almost no hair and two horns. The front horn averages 60 cm, but occasionally reaches 150 cm in length.
Comentários