Of only fifteen species of cranes in the world, just two species occur
in the western hemisphere: the sandhill crane, which is the most numerous, and
the whooping crane, the rarest. Why have the two North American species
experienced such different recent fates? By Elizabeth H. Smith (Prairie Fire Newspaper).
http://www.prairiefirenewspaper.com/2014/04/what-do-whooping-cranes-do-in-the-winter
