Photograph by Joel Sartore, National Geographic Creative
The largest flying bird in North America, the California condor (Gymnogyps californianus) has a wingspan of nearly ten feet.
A captive-breeding program is slowly restoring the species, its numbers reduced to a few dozen by egg poaching and poisons in the 1970s.
Photographed at Phoenix Zoo, Arizona.
The National Geographic Photo Ark is a multi-year effort with photographer Joel Sartore to photograph all captive species and save these animals before many disappear.