There are two types of bison, American and European. There are also two types of buffalo, African and Asian. I have seen herds of Cape Buffalo in Africa and have also seen Water Buffalo in Asia.
I just returned from our Western Explorer trip and we saw a great number of American Bison which are commonly and mistakenly called Buffalo. There are no native buffalo in North America.
African Cape Buffalo
And since the statues that stand on the outskirts of Buffalo New York are actually bison should the city be re-named, Bison New York? And should their sports team be called the Bison Bills?