• Hartman, Fred E.
  University of Maine Graduate School
  

Studies were conducted on the ecology of waterfowl, chiefly the black duck, in the Penobscot Estuary during late fall and winter of two years. The important aspects of this study were the food habits of the birds, and their movements and behavior with respect to the abundance of food organisms and environmental factors in the intertidal zone was investigated.

A definite relationship exists between the availability of food organisms and the types of food consumed by black ducks. The intertidal zones containing the largest numbers of clams are usually utilized the heaviest by ducks for feeding. Animal organisms, chiefly clams, constituted the bulk of the food material taken during fall and winter. Other prominent animal foods are snails and amphipods. Vegetable foods are most important in areas in which considerable marsh habitat prevails. Cordgrass is the principal vegetable food at these seasons. Edible mussels and clams form the bulk of the diet of goldeneyes and scaup.