All 18 of the young whooping cranes that were led south from Wisconsin to Florida by ultralight aircraft last fall were killed by the storms that hit Florida February 1, 2007. They were being kept in an enclosure at the Chassahowitzka National Wildlife Refuge near Crystal River. Over the past six years, this carefully tended migratory flock has grown to 81 birds, but now it’s back to 63. Operation Migration will continue its work with the new chicks that are expected to hatch in two months. The whooping crane, the tallest bird in North America, was near extinction in 1941 with only about 20 left. (James A. Carlson, AP, 2/4/07)