Biologists in California are bringing back the red-legged frog

02:00

The iconic red-legged frog, California's state amphibian, was almost wiped out at Yosemite National Park thanks to natural and man-made enemies. The San Francisco Zoo is making history by breeding a new generation of the amphibian in captivity, hoping to create a model for other threatened species. Now the frogs are ready to take their first leap back into the wild.