The colors
on the male common merganser -- the long white sides and the breast contrasting
with the dark head and dark back -- show a pattern unlike any other
waterfowl. Although this bird can be seen from far away on a calm river
or lake, the dark and white patterns match the dark shadows and sunlit
patches of the forest and the dark water and white rapids of the stream.
These colors are an adaptation for being perfectly "hidden"
while spending summer nesting seasons in, over, and near a forest stream.
The females are better camouflaged than the males. Their back and sides
are gray, their head reddish brown with a crest of feathers protruding
off the back of the head. Other adaptations for both the male and female
include a long, straight bill, with a saw-edged upper mandible to be able
to hold onto fish.
When feeding, mergansers dive quickly with a forward curving plunge.
They swim swiftly underwater. Their diet includes minnows, sticklebacks, suckers,
fish eggs, insects, larva and crustaceans.
In that hidden place by the mountain lake or stream the female lays 8
to 11 eggs that she incubates for about 30 days. When the young leave the
nest after 24 to 48 hours they can find their own food and follow their
mother. She tends the young until they can fly, about 70 days. |