Effect of Diet on Visceral Morphology of Breeding Wood Ducks

Abstract

Changes in Wood Duck (Aix sponsa) digestive organs reflect adaptations to accommodate changes in diet quality, metabolism, and food intake. The size of the gizzard, intestine, ceca, and liver of males decreased between fall and spring and correlated with a reduction in the fiber content of the diet. The mean size of the intestine, liver, and ceca of hens increased in response to high dietary fiber in fall and hyperphagia during laying. Decreases in the size of digestive organs in hens were associated with reduced feeding during incubation and decreased dietary fiber between fall courtship and prebreeding.