Kearney, Nebraska is the Sandhill Crane capital of the world, and there's a big sign at the entrance of the city to prove it. Every year, one of earth's greatest spectacles occurs between March and April, where over 600,000 Sandhill Cranes make a pit stop to feed in the Platte River before continuing their journey north. The sound alone is something you will never forget.  Sandhill Cranes have a distinct call,  like a soft, high pitched rattle.  It's hard to describe, but,  t