Formerly extinct ibis taught to migrate by following light aircraft

Birds bred in captivity are led on their three-week migration south from Germany by human 'foster parents' in light aircraft Leaning out of an ultralight aircraft, Corinna Esterer turns toward a flock of peculiar black birds soaring just a few metres away. "Come, come ibis," she yells through her megaphone. Drawn by Esterer's voice, the birds dart to the aircraft, and follow it to a field overlooking Lake Constance in southern Germany. Once on the ground, the ibis flock to Esterer. To the birds,...