The rhino is one of my favorite animals and I think of them as nature's tank. There are basically two species of rhino, the white and the black. The white rhino is larger and somewhat calmer. Calmer maybe, but I would not suggest encroaching on their comfort zone. Calmer does not mean tame. The white rhino weighs in at about 5000 pounds for males and 3500 for females. The name white rhino has nothing to do with their color, but comes from the old term "Wydt Rhino" which aludes to the wide upper lip, used for grazing. The black rhino has a more rounded lip and is more aggressive, although smaller weighing in at approximately 1900 pounds. One should exercise extreme care in the vicinity of these animals. After all, even the black weighs twice as much as a large grizzly. One interesting behavior is that when running, the calf of the white rhino will run ahead of the mother while the mother runs with her head down. The black rhino will preceed the calf and run with its head up. Apart from man, the adult rhino has no natural predators. The rhino does though back down from an elephant. Or at least I've seen the white do this, not sure of the black. On our most recent trip to Africa, we were fortunate to encounter a black Rhino in Etosha park Namibia as well as one just off the road in Kruger. The sighting in Kruger is rare.