Hooded Merganser - Lophodytes cucullatus

The Hooded Merganser, Lophodytes cucullatus, is one of the last ducks to appear in the fall, and is always a welcome sight. They favor secluded ponds and streams, and are rather shy, so I was pleased to learn that a pair of Hooded Mergansers had returned to the pond just north of the Marin City shopping center, sharing the habitat with a score of American Wigeons. The "hood" refers to the crest, a rather spectacular oversized structure that can be quickly fanned in a startling display, as shown by this male trying perhaps to impress the American Wigeons that were crowding him in a channel off the pond. The female Hooded Merganser paid no attention to the activity.

Male Hooded Merganser swimming with crest retracted

In the next photo the male has started to erect his crest, either to impress the female Hooded Merganser or to intimidate the nearby American Wigeons.

Crest now fanned out to perhaps 60%. Doubt that the female has noticed.

The American Wigeons began to surround the Hooded Merganser, probably because there was simply not much room in this small channel. The birds showed no agonistic behavior, but it seemed that the closer the wigeons got the more the crest became erected.

Crest fully raised. Female merganser no longer close. Pictures are sequential.

Another shot of the male Hooded Merganser with his fanned crest. He's now surrounded by the wigeons, who essentially ignored him. Read more about mergansers below the photo.

The Hooded Merganser is 18" long, a bit smaller than the American Wigeons.

The Hooded Merganser winters here in a variety of freshwater habitats, such as quiet ponds, streams, rivers, and tidal creeks, avoiding marine areas and large open lakes and bays. It is our smallest merganser, and takes more crayfish and insects than it does fish. It's really not very closely related to the other mergansers, and shares an affinity to the Bucephala ducks (Goldeneyes and Bufflehead). In fact the Hooded Merganser and Common Goldeneye are unusual in that they both have the ability to change the shape of their lens (accommodation) to allow them to focus on close objects as they hunt for prey by sight when they dive, virtually always in clear water.

Lophodytes is a monotypic genus, and in fact the word means "crested diver" (Holloway, Dict. of Birds). The Hooded Merganser is the only merganser with a breeding range limited to North America, and there are no subspecies described. World-wide there are only 6 merganser species in all. 4 mergansers are in the genus Mergus (Common, Red-breasted, Scaly-sided, and Brazilian Mergansers), and the Smew, aka White Merganser, is in the monotypic genus of Mergellus.