ONCE UPON A time in Wyoming, I watched a pack of wolves hunt and kill. I stopped the car and got out because a row of people were standing by the road, staring out over the scrubby hills of Yellowstone National Park. At first I couldn’t see anything, but then a flicker of movement in the far distance, black against a pool of snow, caught my eye. Something – several things – were running very fast indeed.

Next to me were a huge man and his little wife. They were serious wildlife watchers, with several pairs of high-powered binoculars and a lens on a tripod. The man said grudgingly that I could take a look through the lens, as long as I didn’t touch it. The flickers turned into a line of tiny wolves racing after an elk. They twisted and turned, sometimes I lost them altogether, but they always reappeared. After a few minutes they took down the elk and it was all over. I could see them gathered round the body but no blood, no tearing and devouring, even with the lens it was too far away.