Counts of reaction distances and reaction behaviors by flocks of sandhill cranes Antigone canadensis in flight toward a transmission power line marked with FireFlys and Swan Flight Diverters bisecting the National Audubon Society's Lillian Rowe Sanctuary in Gibbon, Nebraska, from 4 March to 8 April 2009, compared to flights toward power lines marked with aviation balls and toward unmarked power lines reported in Morkill and Anderson (1991). Small flocks were composed of one to three individuals; large flocks were composed of four or more individuals (Morkill and Anderson 1991).