The common merganser (North American) or goosander (Mergus merganser) is one of the largest ducks but is less stocky than the eiders and goldeneyes. It is a large seaduck of rivers and lakes in European, Northern and Central Palearctic, and North America forest areas. These are large, long-bodied ducks with thin, spiky wings. Their bills are straight and narrow, as opposed to a “typical” duck’s broad, flat bill. Females in the back of their heads have shaggy crests. The first formal description of the common merganser was by the Swedish naturalist Carl Linnaeus in 1758 within the tenth edition of his Systema Naturae. In-flight, they seem more elongated than other ducks, flying in trailing lines near the water’s surface. Common male mergansers have a crested greenish-black head and upper neck. The lower neck, breast, and underparts are creamy-white with a pink wash variable. They have white scapulars on their black backs and upper wing coverts. The bill is red with a nail and a blackish culmen. The feet and legs are deep red. Female common mergansers have a tufted red-brown head, which is clearly defined by a clear whitish chin from the lower neck. Silver-gray on the back and sides, white on the breast and belly. The bill is red with a nail and a blackish culmen. Her feet and legs are bright red.
Common Mergansers dive underwater to catch fish. After the chicks leave the nest in summer, the feminine stays with them as they develop while males furl flocks. Mergansers form large flocks at inland reservoirs and rivers in winter. They stay to feed and court in those tight flocks during the cold months. They mix with other fish-eating, diving ducks such as Bufflehead, goldeneyes, and other merganser species during migration and winter. Common mergansers breed from Alaska, the southern Yukon, Labrador, and Newfoundland south to focal California, Arizona, New Mexico, southern Chihuahua, and east of the Rockies to Minnesota, Michigan, New York, New England, and Nova Scotia. Basic mergansers home in tree cavities, home boxes, bluff fissure, and on the ground, by and large, close to clear-water waterways in forested areas and on the rocky landscape. Average 9-12 eggs were laid by female common mergansers. In particular, the majority of the Western European male population migrates north to estuaries in northern Norway’s Finnmark (mainly Tanafjord) to moult, leaving the females to care for the ducklings. A lot of littler quantities of males additionally use estuaries in eastern Scotland as a shedding region. These ducks live for the most part on freshwater streams and lakes. They are uncommon in the sea, yet they here and there use saltwater estuaries in winter. They home in tree cavities in northern backwoods close to streams and lakes. Presently, exact populace data doesn’t exist for normal mergansers. However, populations are thought to be stable.