Editing Common merganser (section)

===Habits===
In most places, the common merganser is equally at home in salt and fresh water. In larger streams and rivers, they float down with the current for a few miles and either fly back or, more commonly, fish their way back, diving all the way. In smaller streams, they are present in pairs or smaller groups, and they float down, twisting round and round in the rapids, or fishing vigorously in a deep pool at the foot of a waterfall or rapid. When swimming leisurely, they position themselves in the water much like dabbling ducks, but they also swim deep in the water like cormorants, especially when swimming upstream. They often sit on a rock in the middle of the water, similar to cormorants, often with their wings half-open to the sun. To rise from the water, they flap along the surface for many yards. Once they are airborne, their flight is strong and fast.<ref name=Hume1880/> 

They often fish in a group forming a semicircle and driving the fish into shallow water, where they are easy to catch. Their normal vocalisation is a low, harsh croak, but during the breeding season, males and juveniles produce a plaintive, soft whistle. They are generally wary, and one or more birds will remain on sentry duty to warn the flock of approaching danger. If disturbed, they will often disgorge food before moving.<ref name=fbi6/> Although they move clumsily on land, they resort to running when pushed to do so, assuming a very upright position similar to penguins, and frequently falling and stumbling.<ref name=Baker1922/>