When Jack Connelly first began studying the greater sage grouse in Idaho in the late 1970s, "it was not unusual to see 500 in a single flock," says the biologist, who is retired from the Idaho Department of Fish and Game. "Today, it would be unusual to see 200." That dramatic decline has made the sage grouse—a large, pointy-tailed bird with showy mating habits—the subject of one of the biggest endangered species battles ever in the United States.