Wildlife spotlight: Common mergansers

Common mergansers (Mergus merganser) are a species of streamlined ducks that float gracefully down small rivers and other waterbodies in North America. They are numerous along rivers in the Northern United States and Canada, including here in Jackson Hole where they reside year-round. 
 
Male mergansers are elegant with clean white bodies, dark green heads, and a slender, serrated red bill. The gray-bodied females have rich, cinnamon heads with a short crest. 
 
Common Mergansers are sometimes called sawbills, fish ducks, or goosanders. The word “merganser” comes from the Latin and roughly translates to “plunging goose”—a good name for this very large and often submerged duck. 
 
In summer, you can find them leading ducklings from eddy to eddy along streams or standing on flat rocks in the middle of the current. In winter they form flocks on larger bodies of water. 
 
These large ducks nest in hollow trees and often in holes carved out by large woodpeckers. Young Common Mergansers leave their nest hole within a day or so of hatching. The flightless chicks leap from the nest entrance and tumble to the forest floor. The mother protects the chicks, but they catch all of their own food. They start by diving for aquatic insects and switch over to fish at about 12 days old.