The northern white rhino could still be saved if an unusual plan somehow works. The last two of the species left on the earth are both female and cannot carry a pregnancy. And time is fast running out for the last of the northern white rhino at the Ol Pejeta Conservancy in Laikipia, Kenya.
Nothing can be a more potent symbol of extinction than these two female species and as they are not able to articulate their predicament, someone needs to do it for them, says Zacharia Mutai, the keeper of the Northern White rhinos at the conservancy.
Najin, one of the rhinos was brought from a Czech zoo where she grew. She now resides in an immense area in the conservancy that has been fenced off. She is among the four rhinos that were transported from the Dvur Kralove Zoo so that they might be encouraged to breed in the large open enclosure. But neither Najin nor Fatu, her daughter, gave birth even after mating. Both the males died subsequently. The younger, Suni died in 2014 from natural causes. Sudan, 45, had to be put down 4 years later due to severe illness and degeneration in his bones and muscles.
Daring Plan To Save The Northern White Rhino
Scientists around the world were not deterred by the setbacks and came up with an unusual plan. They plan to use the sperm of the dead males, Sudan and Suni, which were carefully frozen. The sperm was collected with the plan to artificially inseminate the female rhinos at the conservancy, including the two northern white rhinos.
But conventional attempts at artificial insemination failed. They then hatched an unusual plan to create an embryo. But to do that they had to get hold of an egg from the female pair.
Procuring eggs from a female rhino is a complicated process as the ovaries, the storing place for the eggs, are almost 4.9 feet (1.5 meters) inside the female rhino. The veterinary experts had to deal with the intestinal loops inside the rhinos which kept obstructing the process, according to Dr. Thomas Hildebrandt of the Leibniz Institute for Zoo and Wildlife Research, Berlin.
Neither can a tube be inserted in the vagina of the rhino, something which is possible with horses and humans. Veterinary doctors go across the abdomen of big cats to reach their ovaries, says Dr. Hildebrandt, head of the reproductive unit at the IZW.
But that process would be complicated and involve cutting through the thick skin of the Northern White rhino, which is about 2 inches (5 centimeters) thick.
While the skin protects the rhino in case of a fight, once cut it refuses to heal properly, and they might eventually die of an infection. Dr.Hildebrandt came up with an instrument of his own to gather the eggs of the Northern White rhino. It consists of a tube that is inserted through the rhino’s anus. A delicate and long needle at the end of the tube is used to pierce the ovary follicle, which stores an egg. A device connected to the needle sucks out the egg through the tube.
Dr. Hildebrandt says that the whole procedure has to be done precisely with the tube, a process patented by him. A mistake could lead to a puncture in a major blood vessel, some of which are as thick as a child’s arm. This would lead to internal hemorrhage and might prove fatal.
So Dr. Hildebrandt uses a 4-dimensional ultrasound scanner. This device enables him to keep continuous track of the whole extraction process. This invasive procedure, though complex, has a minimal consequences on the female rhinos, but the whole process has to be completed in a couple of hours. That is the maximum time for a rhino to be kept under sedation.
Using this process, Dr. Hildebrandt managed to remove 19 eggs from both Fatu and Najin.
A Dash Across Continents To Save The Northern White Rhino
The subsequent step of the process involved fertilizing the eggs with the dead northern white rhinos’ sperm which has been kept frozen in labs. This process needed the assistance of an IVF expert. Cesare Gallim an in vitro fertilization expert based in Avantea Private Lab in Italy was chosen for this task. So the collected eggs were rushed to Italy.
Normally sperm collected from rhinos are of poor quality as they contain urine. Professor Galli knew what he was up against as he had faced this problem in the past. Sperm is extracted artificially from male rhinos by electrocuting them. This causes the discharge of sperm, urine, and various other liquids.
It took Dr. Galli years to refine the method to form an embryo. He used electrocution to make the egg fuse with the sperm and form the embryo. He had perfected the procedure with the southern white rhino and the Sumatran rhinos. This method worked perfectly. He was also confident about the process that would produce an embryo of the Northern white rhino. The first two embryos were made with the initial batch of eggs delivered to him in August 2019. The second batch delivered 4 months later yielded another embryo.
The embryos have been preserved in Dr. Galli’s lab. But now he needs a womb for them to grow. But tragically neither Najin nor Fatu is incapable of holding an embryo in her womb. An examination revealed that she did not have the uterus lining needed to complete a pregnancy.
Najin, Fatu’s mother had a different complication. Her hind legs are weak from the hormone, progesterone, released when she was pregnant. It severely affected her legs. She would have been unable to get up once she fell, killing the embryo and harming the mother.
Using Surrogates To Save The Northern White Rhino
Previous attempts to place embryos in the southern white rhinos had not been successful. Getting the timing right has always been an issue for scientists trying to impregnate a rhino through surrogacy.
Knowing the exact time when the body is ready for the embryo to attach to the lining of the uterus is difficult. In women, the time to implant an embryo is determined by their menstrual cycle.
The scientists determined that the chances of the surrogate successfully carrying the embryo to its birth is highest if it is impregnated after she has sex.
The scientists have employed that strategy by waiting for the southern white rhinos to have sex with a sterilized male and then placing the embryo of the Northern White rhino in her womb. All they can do is now wait and hope.