Mergus merganser americanus
Goosander, saw bill, fish duck, sheldrake, grand harle, mergo mayor
Rare in winter and rare to occasional in spring and fall in primarily the Tennessee Valley region. Low Conservation Concern.
A large diving duck with a length of 21.3-27.1 inches and weight of 2.1-4.5 lbs. Males have a greenish black crested head and upper neck. The lower neck, breast and underside are creamy white with a pink wash. The back is black with white scapulars on the upper wing coverts. The females are dull gray with a reddish head and white chin. Both sexes have a long narrow bill with serrated edges that is red with blackish culmen and nail. Legs and feet on both sexes are a deep red.
Among some of the largest duck species, common mergansers are less stocky than elders and goldeneyes. When in flight, the common merganser flies close to the water surface in a trailing line and each individual looks elongated compared to other ducks in flight
Common mergansers are found from Alaska to New Foundland, southward to New Jersey, Minnesota, New Mexico and California during the breeding season. As winter migration season begins, common mergansers will move south from Southern Canada to North Carolina, Kentucky, Arkansas and Northern Mexico and farther north along the coast. They will also migrate to Eurasia southward to northern Africa and northern Vietnam.
During the breeding season, common mergansers prefer lakes and rivers that are bordered by forest. During the winter months, they can be found resting and feeding on large lakes, rivers, coastal bays and estuaries.
Common mergansers feed by diving under water to obtain both marine and freshwater amphibians, crustaceans, mollusks, and a variety of invertebrates but mainly fish species.
LIFE HISTORY AND ECOLOGY:
Common mergansers will start forming breeding pairs once they reach their breeding grounds in the north. Common mergansers will nest in tree cavities, nest boxes, cliff crevices, holes in the ground, hollow logs or old buildings that are next to water in forested regions and mountainous terrain. The female will line the nest with downy feathers from her chest. She will then lay a clutch of 6-17 creamy white eggs and incubate them for 28-35 days.
Once the eggs have hatched, the young will leave the nest in about one to two days. The female will lead her young to water where they will feed mostly on aquatic insects then switch to fish at about 12 days of age.
Bellrose, F.C. 1976. Ducks, geese and Swans of North America, 2nd ed. Stackpole, PA
CORNELL LAB of ORNITHOLOGY, All About Birds-https://www.allaboutbirds.org/guide/Common_Merganser
Phil Miller, Wildlife Biologist, Division of Wildlife and Freshwater Fisheries