Humans dressed up as birds, puppets, and ultralight planes. These are the ingredients in an ambitious plan to save the endangered whooping crane population of North America. And it 's workings. Slowly. Back in 1940, the entire whooping crane population was estimated at less than twenty. Now, the captive and wild population has increased to about 400. Not bad, given the obstacles that had to be overcome. Whooping crane chicks are being raised in captivity, by handlers dressed in white to hide their human form, with crane-head puppets attached to their arms. Which they use to teach the young birds crane behavior. When it is time to migrate south, the young cranes do not have adult cranes to lead them, si they don 't know the way. That 's