It’s December and the ducks — lots of them — are here

Winter is the season for watching ducks. In spring, the great majority of our ducks will head to their nesting grounds to the north, leaving mallards as our only common and widespread breeding species. And their fall return is later and more gradual than that of wading shorebirds, which become notably abundant in July and August, with many ducks continuing to arrive over the course of October and November.

But now it’s December and the ducks are here.

There are a lot of them: teals and wigeons, gadwalls and shovelers, pintails and scaups, buffleheads and canvasbacks, ruddy ducks, goldeneyes, mergansers and more. They are large, often stay relatively still for an extended period of time, and many have bold and distinctive colors, making them a good family for beginning birdwatchers to study.

So how can you start to get a handle on the wide world of waterfowl?

A wise starting point is to clarify which birds are ducks and which are not. You probably have a general idea of some of their most prominent characteristics: relatively wide bills and webbed feet, both of which are shared with their relatives the swans and geese. Ducks, swans and geese are collectively referred to as waterfowl; ducks are generally smaller, have distinct male and female plumage, and raise their young through maternal guardianship only, while swans and geese are larger, have similar male and female plumage, and raise their young in two-parent families.

Note that there are a number of other swimming waterbirds that are not ducks. Coots, gallinules, grebes and loons have a superficially similar shape and are seen similarly floating on the surface of the water or diving for food. Remember to look for the broad bills and webbed feet of ducks if you’re confronted with something that doesn’t match the patterns I describe here—maybe it isn’t a duck at all.

When you do find a pond full of authentic, genuine, legitimate ducks, however, you’re still faced with a rather large suite of possible identities. If you’d like some kind of organizing framework rather than one long list of species, the most general division is between “dabbling ducks” (or “puddle ducks” or “surface-feeding ducks”) and “diving ducks.”

The first group is less internally varied, with most of our local representatives falling in the same genus (Anas) and sharing a broadly similar anatomy. Familiar mallards epitomize this group, with a wide bill and legs relatively central under the body (to favor walking, rather than the more rear-mounted legs of diving birds). There is some variety: northern shovelers have the widest bills, green-winged teal are significantly smaller, northern pintails have elegant white neck patterns and long pointed tails in males. But the overall shape and habits of these ducks are broadly similar, along with other relatives such as gadwalls, cinnamon and blue-winged teal, and American wigeons.

The diving ducks are much more varied, although smaller groups of related birds can still be picked out. We have three mergansers (“sawbills”), which have teeth-like protuberances on their bills for gripping fish: common, red-breasted, and hooded merganser. Goldeneyes and buffleheads are relatively small, black and white diving ducks. Scaups and canvasbacks often gather in large rafts on the bay. One of the most unique is the ruddy duck, our only representative of the “stiff-tail” group and an endearingly cartoonish little duck possessed of numerous equally endearing folk names such as little soldier, copper breeches, and stub-and-twist.

So where can you go to see ducks around the North Bay? The classic birder suggestion is to head to your nearest water treatment facility, where year-round nutrient-rich water is always reliably found, often paired with easy proximity to town and flat, easily-accessible paths. Our two best such locations are the Las Gallinas Ponds in San Rafael and the Ellis Creek Ponds in Petaluma.

For more natural settings, head to the Cemetery Marsh area of Rush Creek Open Space Preserve, Marin Audubon Society’s Bahia Lagoon, Pacheco Pond, and the Hamilton Wetlands (all in Novato); the San Rafael Bay Trail; Corte Madera Marsh, Rodeo Lagoon in the Marin Headlands, and Limantour Estero and Abbotts Lagoon in Point Reyes.

Jack Gedney’s On the Wing runs every other Monday. He is a co-owner of Wild Birds Unlimited in Novato and author of “The Private Lives of Public Birds.” You can reach him at jack@natureinnovato.com.