Egg size, body size, locomotion, and feeding performance in captive King Eider ducklings

We studied the effect of egg volume and body size on swimming speed. endura nce, and feeding rate in captive King Elder (Somateria spectabilis) ducklin gs in the Canadian arctic. Sprint speed, endurance, and feeding rate were p ositively related to egg size and body size. Large ducklings from large egg s performed better than small ducklings from small eggs. Ducklings that are more capable swimmers and have higher feeding rates may grow more quickly and be more effective at predator evasion. Thus, ducklings from large eggs may have a survival advantage over those from small eggs under conditions w here predation and nutrition may constrain survival.