The Biologist Who Counted to One

In the late 1990s, when gray wolves were reintroduced to Yellowstone National Park, wildlife biologists fitted each animal with a radio collar and gave it a number. Wolf 9F — a breeding female in the Rose Creek Pack — became one of the most closely monitored animals in American conservation history. When her signal went silent one January morning, biologist Mike Phillips didn't shrug and say, "We still have fifteen others transmitting fine."…