May 26, 2015, Los Angeles, California — When you’re searching for a California Condor, two field marks are particularly helpful: Look for (1) a bird so big it may be mistaken for a small airplane, and (2) the large number tags on each wing. (Remembering, of course, that airplanes also have registration numbers.) You’ve probably heard about California Condors, North America’s largest land bird, but their story bears repeating. The species came within a pinfeather of extinction in 1987, when the population dropped to just 22 individuals, all of which were taken into captivity. A last-ditch breeding program has since boosted numbers up to several hundred birds, and, with heavy support from a few dedicated humans, released condors are nesting again in several spots in the western U.S. Their existence remains tenuous, however, perhaps more so than most of us realize. Condors, because they eat carrion, are prone to ingesting lead shot from animal carcasses. Many of them depend on...