You had heard of St Matthew Island, the narrow strip of arctic tundra far out in the Bering Sea. You had heard how in 1944 the US Coast Guard had shipped in twenty nine reindeer as food for the navigation station personnel, and how in the rush of the end of the war they had been left behind.
You were curious about what would have happened to a herd with abundant food and no predators, and in 1957 you got a chance to visit. You found 1,350 fat reindeer. It seemed ideal; the herd density matched the capacity of the land. But small patches of overgrazing made you wonder.
Six years later you went back to find innumerable tracks and droppings and bent-over willows. The reindeer numbers had exploded to 6,000, but they were thinner now, stressed.
The winter of 1965 was too severe to return. A plane flew over but saw no deer. The pilot refused to fly lower. Did you miss them? In July 1966 you found an island littered with skeletons and only forty two reindeer. There were no active males. Soon the herd would be extinct. The unintended experiment had come full circle; arctic foxes would again be the largest mammal on this windswept island.