In 1967 the flock had 48 birds. Cranes normally lay two eggs, but it is rare to raise two chicks. Scientists began taking one of the eggs from a few whooper nests, leaving one egg for the birds to hatch. They took six eggs in all.

The biologists took the eggs to a special place to be hatched. The plan was to start a captive flock of Whooping Cranes. Those cranes would lay more eggs that could be released back into the wild. This would help grow the endangered Aransas/Wood Buffalo flock — the world's only natural wild Whooping crane flock.

Photo: Canadian Wildlife Service