Seasonal energetics and behavior of captive canvasbacks (Aythia valisineria)

Dramatic changes in the food habits and distribution of Chesapeake Bay canvasbacks (Aythya valisineria) generated a desire to better understand the energetics and behavior of this species on its wintering grounds. Captive canvasbacks were maintained ad libitum on 5 diets during the winters of 1978-80 to evaluate varying protein and energy levels in the diets. Food consumption, weight, blood, and behavior were variables measured to assess affect of diet. Food consumption was higher (P