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