Grandfather tossed into the air by 2,000lb bison in Yellowstone

A 65-year-old man was hurled metres into the air by a bison in Yellowstone National Park after stopping to take a photograph with his grandson. The bull bison, which witnesses said weighed 2,000lb (900kg), charged at Carl Isom-McDaniel and his grandson on Friday evening at Bridge Bay Campground near Yellowstone Lake. Video captured by Mike Macleod shows the pair walking at a safe distance before the animal, agitated, flops on its side repeatedly and then leaps to its feet. A white truck approaches but speeds off after the bison charges it. The animal then barrels towards the man and boy, leaving a cloud of dirt in its trail. They try to evade it by running through a thicket of trees, but the bison catches Isom-McDaniel. "The bison hooked him with his left horn on his hip and tossed him in the air," Macleod told the Cowboy State Daily. "He made a perfect flip and landed on his side." Isom-McDaniel sustained multiple injuries and was taken to hospital, according to the New York Times. He was conscious and "in good spirits, joking", Macleod added. The National Park Service (NPS) has not released any information about the attack. On its website, the NPS warns that bison have injured more people in Yellowstone than any other animal. "They can run 3x faster than humans, making it very important to give them plenty of space," it says. Visitors are advised to stay at least 25 yards (23m) from bison and to "never approach a bison to take a photo". The incident occurred during summer, the busiest season in the park. Nearly 60% of annual visitation happens in June, July and August. July also overlaps with the bison's mating season. Jennifer Barfield, a professor at Colorado State University and scientific lead at the Laramie Foothills Bison Conservation Herd, said testosterone levels among bulls are heightened during this period. "That's really going to drive their behaviour, and they're going to be potentially more unpredictable than at other times of the year," she said. Barfield added that her team stays away from the bison during mating season except for necessary observations. The fate of the bison remains unknown.