Back in 2009, Najin and her daughter Fatu were brought to the big enclosure in a last attempt to get them to breed and re-grow the population.
Though the four rhinos mated, neither of the females gave birth.
The two male rhinos die after a few years. One of them had to be put down, and the other dies of natural causes.
Scientists have collected rhino sperm to inseminate the remaining females ultimately.
Only two subspecies of white rhinos exist in Africa – the northern white rhino, which is nearly extinct, and the more frequently encountered southern white rhino.
Unfortunately, all insemination attempts failed.
The solution was fertilizing an egg by sperm in the lab. However, the new problem was obtaining the egg.
The ovaries of the rhino, which is where the eggs are stored, are located over 1.5 m inside of a female rhino, which made the task a lot more difficult for the veterinary expert that had to conduct the operation.
Also, the job was made harder by intestinal loops that got in the way.
Some makeshift device was used that did minimal to no harm to the rhino.
They managed to fertilize the egg successfully, but they’ll have to find a surrogate mom because neither of the two remaining females can bear an offspring.