Northern Prairie Wildlife Research Center
When flushed from the nest during egg-laying and early-incubation periods, female canvasbacks (Aythya valisineria) invariably leave by way a lane, swimming to open water, and then flying if approached too closely. Some leave while the canoe is still a quarter mile (0.4 km) or more away. Towards the end of incubation the female sits closely, flushing directly from the nest when the intruder is a few yards away. After absences induced by disturbance, the hen may return to find her brood dispersed and may fail to retrieve them all.