To look at, most would be hard pushed to tell the difference between a northern and a southern white rhino. The northern variety is smaller on average, with a straighter and more level back than those in the south. They also have a distinctively shaped skull, which is less concave and a lot flatter, and they have hairier ears and tails. Their dentition is also distinct from the southern variety.
These morphological differences, and genetic evidence to suggest that the two populations have been separated for at least a million years, has led to some suggesting that the northern and southern rhino should actually be classed as distinct species in their own right. If so, it means there are profound implications for the animal’s conservation, making the loss of Sudan all the more significant and tragic.
While the southern white rhino is one of conservation's biggest success stories – at one point there was as few as 15 individuals – the decimation of the northern white rhino is one of embarrassment. Because of where the northern ones resided, in countries that have experienced little stability over the last century, they were more heavily targeted by poachers. Considered part of the same population as the southern rhino, little action was taken when it was needed.
This resulted in the species going extinct in the wild, with all hopes pinned on the few that remained in captivity. Eventually, the four northern white rhinos left at a zoo in the Czech Republic, which included Sudan's daughter and granddaughter, were moved to Kenya where they were given 24-hour armed protection. Now they are the last survivors.
With all efforts now being plunged into IVF, the technology could not only be used to save the northern white rhino but also the critically endangered Javan and Sumatran rhino, which are also very close to extinction.