A: To prevent time-wasting edit warring. As the name has been agreed years ago please spend your valuable time improving the article and the lives of the animals instead of arguing about the name.
Q: I am proud to be Ruritanian and these Ruritanian leopards have been mentioned in a scientific paper. So can I add "Ruritanian leopard" as an English name?
A: The paper might have been referring to the population which lives in Ruritania to distinguish them from the same species in another country. But IF the name becomes COMMONLY used nowadays in English for the species rather than the population then go ahead and add it.
