In the black water of a wooded pond, a pair of ducks quietly rest. The female is a somber gray brown with a rusty-colored head and a bushy crest. The male, in contrast, is striking.
The head sports a large, white, rounded crest bordered in black that shows brightly even in the shadowed pond. The crest is lowered most of the time, but the white still shows as a broad line behind the eye. The white breast is marked by two black slashes beginning at the shoulder. The sides are a warm rusty brown, and the black feathers of the back are long and streaked with white. The hooded merganser is one of the most beautiful ducks anywhere and a regular resident in our area in winter. This is also the time of year they select their mates.
Courtship can be an undignified affair for many animals — even humans. At least that’s how it often appears to an outsider. This applies to the hooded merganser, as well.
In the dim light of a sheltered pond in the drear of winter, the bold black-and-white plumage is used to full advantage when courting mates. The performance is rarely observed. The one time I had the fortune to observe the display, three males were competing for the attention of two females. The males would rise up in the water, spread their impressive crest and throw their heads back — bill to the sky — as they settled back into the water. The yellow eye accented the display and gave them a slightly crazed look as they performed. This was accompanied by a soft croaking call as well as much head shaking and posturing proudly displaying the bold crest. One after another the males repeated their exaggerated dance as the group paddled among the shadows of the willows rising from the water.
My bike often takes me along Bear Creek. I watch and listen for wildlife as I ride, especially for mergansers in winter. I typically see four to six of the larger common merganser and more often than not a pair of hooded mergansers.
As in all mergansers, the long, thin bill is lined with small tooth-like projections. These aren’t real teeth but serve a similar function. Instead, they are made of keratin, the same substance that makes up the bill (and your fingernails). These tomial teeth, as they are called, help secure the slippery items that make up their diet.
This winter I have seen fewer mergansers than usual along Bear Creek, especially hooded mergansers. This suggests that food in the creek is not as abundant this year. They feed extensively on aquatic insects such as caddis flies and stoneflies, as well as fish and crayfish. Warm temperatures and low stream flows last summer likely had an impact on their food supply, especially some of the more desirable aquatic insects. I also suspect that last year’s heat and low water may have discouraged some salmon from coming far up the Bear Creek drainage, producing fewer young in the creek in winter.
Stewart Janes is a biology professor at Southern Oregon University. He can be reached at email@example.com.