Butterflies, snakes and flowers: In rugged Baja canyons, San Diego scientists unlock an unsung region’s biodiversity

Sulphur butterflies glide across Zorrillo Canyon, hundreds of them, moving back and forth against the cerulean sky. It’s nothing short of a fairy wonderland for the scientists below.

At least, that’s how Jon Rebman, curator of botany at the San Diego Natural History Museum, describes it as he begins the hike into the canyon on a late October morning.

Jon Rebman, curator of botany at the San Diego Natural History Museum, hikes through Zorrillo Canyon in the S...