Should the condor, which had almost been wiped out by habitat loss, hunting, and eating carcasses that were poisoned by lead bullets, be left to die in the wild?

Or should scientists take the remaining 22 condors into captivity and breed them, which would cost millions of dollars?

Sanjayan's view was that humans had a moral responsibility to save North America's largest flying bird.

That's exactly what happened: Captive-born condors were reintroduced into the western United States in the early 1990s. There are now more than 200 in California, Arizona, and northern Mexico.

On a recent trip to the Grand Canyon, Sanjayan—now the lead scientist at the Nature Conservancy—looked up and spied one of the big black birds soaring above.

"That's pretty incredible if