Northern Shoveler - Anas clypeata

In September the ducks return to the San Francisco Bay Area in good numbers, but most will be starting molting from their cryptic eclipse plumage into the bright breeding plumage they wear most of the year. Juvenile ducks and male duck in eclipse plumage often strongly resemble the adult female, so identification can be a challenge.

The Shoveler shown here was seen on Sept 17 at Las Gallinas. I figured it was a female Northern Shoveler, but several features suggest it may well be a male in eclipse plumage. The yellow-orange iris is similar to the bright yellow in the adult male, whereas juveniles and females have a browner iris. The head is a dark gray, while females and young shovelers would be more brown. The chest, breast and flanks on this birds have an attractive rufous wash, unlike the muted browns seen on females and youngsters. Bill color much like a female's, but the male's bill will only become black in full adult breeding plumage. So I'm going the an adult male in eclipse plumage.

Here's an older shot of a female. Note the brown iris and pale brown head.

Male Shovelers go through a more variable and prolonged molt than most other dabbler species, so most of them won't display the deep green-black head, rich chestnut flank color and striking white breast until late November.

Northern Shoveler - Anas clypeata

By November most of the male ducks are in "alternate" plumage, meaning they have largely completed the molt into the bright breeding costume worn most of the year. The Northern Shoveler is an exception, as Ralph Palmer writes (Handbook of NA Birds,  Vol. 2), "…in some individuals either the whole (molting) process is gradual and prolonged, or the major portion of it occurs late…". Thus, at times we see some interesting and at times puzzling male Northern Shovelers.

The first photo, 11/22/13, shows a typical female Northern Shoveler, with the cryptic feathering on back and flank common to most female dabbling ducks in the genus Anas. Her large spatulate bill always has some orange coloring, and her face has only a subtle post-ocular stripe.

The male in eclipse plumage looks a lot like the female, with cryptic coloring on the back and flank, but his yellow iris, black bill and darker head help with the ID. Some of the male shovelers that we seen in Nov-Dec. retain parts of the cryptic feathering on the back and flank, and shown in the second photo (Colusa NWF, 12/07/13). Part of the flank now shows the chestnut color and his head is well along to the black color of winter. It's fun to see one with a white crescent on the face near the bill, sort of like a Blue-winged Teal male.

The next photo shows a typical male in alternate plumage, with dark head and back, black bill, rich chestnut on the flanks, and bright white breast. 

Below we get a peek at the powder blue wing patch in this less typical back view. Note the bright orange legs.