Story : The giant bison were at risk of disappearing forever. Now, in the Yellowstone caldera, the bison are back. But this symbol of America would not exist without its fearsome adversaries. And now, they are back too…the wolf and the grizzly, ready to kill. Here even the landscape can bring death. Then there is the war season, when the bison fight among themselves. For the first time in almost a century, the bison faces its ancient rivals in the “Serengeti of America”… Tonight on Superquark, in the fascinating National Geographic documentary. Numerous, as always, the reports and columns, including: Parkfield, a small town in California, is a center that is monitored carefully. And the studies that are carried out on site can be very interesting for us Italians, for radon and earthquakes. Alberto Angela takes us on a curious journey through the history of means of transport.