Common Merganser
Mergus merganser
Synopsis: Nests widely throughout Oregon along lakes, larger streams, and rivers. Nests in tree cavities or on ground.

Habitat Associations:
strongest
Lake/Pond Shoreline & Islands (498115 acres)
Western Oregon Riverine Woodland (22952 acres)
strong
Streamside/Wetland Shrubland (2171 acres)
lesser
Red Alder (50097 acres)
Edges of Freshwater Marsh (10399 acres)

Relative Detectability: Easy to spot and to confirm nesting, usually by noting fledglings accompanied by adults.

Challenge: Improve knowledge of distribution along eastern Columbia River and its tributaries.