I am very glad I borrowed and read Return of the Whooping Crane by Robin W. Doughty. While the book is at this point 25 years old and there must be more of the whooping crane story to tell, I was totally absorbed by the details of the story from which I come to two conclusions
The first is that whooping cranes in the wild are not really saved yet. There is stability in that the flock that migrates between the Aransas National Wildlife Refuge in Texas and Wood Buffalo National Park in Alberta and the Northwest Territories has in recent decades constantly grown. It was up to 278 cranes in 2011 (International Crane Foundation) There were at the same time 321 whooping cranes in other locations, including preserves, zoos, and a recent East Coast migratory flock. But the Florida non-migratory flock is shrinking, and the Rocky Mountain flock has already failed.
The second point is that it is really difficult to reintroduce cranes to the wild. Doughty documents years of trying to get sandhill cranes to foster whoopers to start that Rocky Mountain flock. The sandhill parents usually did well-enough to hatch and raise the whooping crane chicks, but mature whooping cranes never seemed to mate even when they found each other. Also, many birds raised in captivity and released into the wild died in bad weather, in accidents with electric lines, or in predation by wolves, coyotes, foxes, cougars, and eagles. At least for whooping cranes through 1989, reintroductions resulted in more dead cranes than survivors.
Despite these difficulties, Return of the Whooping Crane is a hopeful book. It tells how laws were passed just in time to stop the feather trade and how low the world's population fell. It recounts extreme efforts by conservationists in the U.S. and Canada over many decades to save the species. It also tells much about crane biology and behavior and includes many beautiful color photographs of whooping cranes. This beautiful book is dated but succeeds still in instilling appreciation and devotion for the cranes.
Doughty, Robin W. Return of the Whooping Crane. University of Texas Press, 1989. 182p. ISBN 0292790414.