Vancouver Island has a large population of Common Merganser Ducks who live here year-round. The common merganser is a beautiful duck, it is a freshwater diving duck, feeding mostly on fish but will also take insects, mollusks, crustaceans, worms, frogs, small mammals, birds, and plants.
This species is referred to as the sawbill due to its long, serrated bill which helps hold onto slippery fish which can be handy because gulls and eagles will wait for these deep-diving ducks to surface and then attempt to steal their catch.
The male in his breeding plumage has a white belly, white breast, and white flanks, along with a gray rump and black back. The head is dark green, the bill is red, and the eye is dark. The female common merganser has a solid gray body with a brown head. She has a narrow, red, serrated bill and a white chin patch at the base of the lower jaw. The short crest of the female is often not obvious.
Common Merganser Ducks like to nest in tree cavities by freshwater lakes or rivers in wooded areas. Nothing is added except some females down. The nest cavity is normally an old nest that was excavated by pileated or other large woodpeckers or where a larger limb has broken off, although I have seen them nest up on rocky cliffs above a stream in elk falls canyon. The common merganser prefers a cavity situated 3 to 8 meters up a tree. When nesting on the ground, the nest is a hollow basin lined with nearby plants and soft feathers.
The Common Merganser Ducks will lay up to 12 eggs, and they are tended to by the female alone. Once hatched, the young remain in the nest for a day or two before leaving with the female. The mother will protect the young, but will not feed them. Fledglings learn to dive to catch their own food quickly, They feed on mainly aquatic insects but learn to catch fish at about 12 days, and they become independent in 5 weeks’ time