** ADVANCE FOR WEEKEND EDITIONS, APRIL 11-12 ** FILE – In this March 17, 2005, file photo, a silhouette of a single snow goose is seen as it flies under the moon at the Middle Creek Wildlife Management Area in Kleinefeltersville, Pa. Snow geese are on their spring migration north to their nesting habitats in arctic tundra regions. A century after teetering near extinction, snow geese are so plentiful in North America that scientists fear their over abundance poses an ecological risk to its nesting habitats and wintering grounds. (AP Photo/Carolyn Kaster, File)
