They are white with black tipped wings and a bare red spot on their heads, however, if they are less than one year old they are a rusty-red in color. One of nature's most impressive and closely watched events, the migration of the endangered whooping crane, will occur across America's heartland during the middle weeks of October. Whooper population reached its lowest population in the winter of 1941-42 with only 15 birds remaining. Southward migration requires up to 50 days including a two-day flight from the breeding range to southern Saskatchewan grain fields. The birds remain one to five weeks, followed by a rapid one to two week trip across U.S. prairie states.
Migration begins with northerly winds, good visibility, and increasing barometric pressure.
The first whooping cranes pass through the Dakotas, Montana, Nebraska, and Kansas is typically sometime in the middle days of October. The first whooping cranes arrive at Aransas NWR around the middle of October . In the Rocky Mountains, three of four whoopers began their migration south from Yellowstone National Park this week to the Rio Grande Valley of central New Mexico, and are currently in southeastern Idaho. Two of the cranes are the only remaining survivors of a sandhill crane foster parent program. This was a trial run where whooping crane eggs were placed in sandhill crane's nests.