From February to early April over 500,000 Sandhill Cranes, Grus canadensis, or about 80% of the North American population, gather along the Platte River in Nebraska where they feed on the on the crop remains in the nearby cornfields.   Rowe Audubon Sanctuary in Gibbon, Nebraska, is at the center of the area where the cranes stop  on their way to places as far away as Eastern Siberia.   The Sanctuary provides an interpretive center, blinds for watching the cranes, and tours of the area.    Sandhill Cranes are one of the oldest bird species alive today with fossil remains of essentially the same bird dating back nine million years.  These images are taken at the Rowe Sanctuary and nearby.