The sheer size and wildness of Yellowstone National Park's signature bison provide a magnificent subject for camera-toting tourists. But officials caution visitors not to come within 25 yards of the animals, noting that they are unpredictable and able to sprint three times faster than people can run. A 62-year-old Australian man who ventured to within 3 to 5 feet of one bison was seriously injured Tuesday when the animal charged and tossed him into the air several times, park officials said in a statement. This is the second such incident within weeks. A 16-year-old Taiwanese exchange student was gored by...