Sandhill Cranes in the dark Bosque Del Apache wildlife refuge

My son in law and I made our almost annual trip to Bosque del Apache wildlife refuge near Socorro New Mexico last week, The bird numbers were way down from normal years but we managed to fine enough to keep us busy shooting. On the last morning we arrived well before sunrise and could hear the birds but couldn't see them, I tried to focus somewhere in the dark and with camera on tripod took a 2 second exposure, after several attempts to guess at focus I finally got this shot. I'm always amazed how a digital camera can find light in the dark.