I have a confession to make. Waterfowl identification in autumn is hard. Blame the ducks.
For starters, ducks aren’t particularly comfortable around humans right now. Most ducks won’t let you get within shotgun range during hunting season, so you need to identify them at a distance. Even then, they’re likely to fly off as you approach.
There are exceptions, of course. Some waterbodies are located in towns where ducks can’t be hunted. Hundreds gather in Sebasticook Lake this time of year, practically in downtown Newport. These ducks are typically closer to shore. It’s a great place to practice duck identification.
Some key field marks are easier to see when ducks are flying. Blue-winged and green-winged teal are named for their bright wing patches, but those are hidden on a sitting duck.
American black ducks and female mallards look quite similar, sitting on the other side of the pond. In flight, the mallard displays a white wing stripe. The black duck doesn’t.
Colorful field marks are only useful when you’re close enough to see them. Depending on light and distance, duck identification may require three steps.
Step one
Is the duck a dabbler or a diver? Even a quarter mile away, you can tell if a duck goes completely underwater. If it’s just tipping up, it’s a dabbler. Based on that one behavior, the entire duck world is divided in two, making it easier to sort out the possibilities.
Diving ducks have legs farther back on their bodies, so they can swim underwater more efficiently. When they take off, they must run along the surface to get airborne. Dabblers can just jump straight up out of the water.
Step two
What size is it? In fresh water, mallards and American black ducks are typically the largest dabblers, also called “puddle ducks.” Since you’ve seen a gazillion mallards over the years, you should have a sense of their size. It’s a safe bet that anything that looks smaller than a mallard isn’t a mallard.
Teal tend to be the smallest dabbling duck alternatives. At half the size of mallards, green-winged teal are even smaller than blue-winged ducks.
Body parts differ by size and shape. Northern shovelers have huge bills. Northern pintails have long necks and slender heads. American wigeons are dainty, with relatively short bills and a rounded head. Gadwalls are similar, with a less rounded head. Wood ducks have block heads. Ruddy ducks cock their stiff tails. These features make good clues at a distance, even if all you can see is a silhouette.
Diving ducks provide similar clues. Mergansers are long and sleek. Goldeneyes, scaups and ring-necked ducks are more squat. Common eiders are the largest ducks in North America, seen mostly on saltwater. They look bigger than every scoter. White-winged scoters are bigger than surf and black scoters. Size matters.
Step three
Finally, field marks. Close views of ducks in breeding plumage make identification easy. Unfortunately, they don’t keep their breeding plumage. After mating, males molt into drab plumage for the rest of summer.
Some of them are coming back into breeding colors now, but there are a lot of confusing plumages out there. It doesn’t help that males and females look vastly different.
There are at least 26 species of ducks found in Maine each year. Many nest here. Others are just passing through. Some spend the winter. I can’t describe them all in one column, but here are a few identification shortcuts.
Four similarly sized diving ducks are mostly black and white. Common goldeneyes and ring-necked ducks have solid black upper backs, whereas greater and lesser scaups are light gray on top. By focusing on the back pattern, you can reduce your identification challenge to two species, rather than four.
Four male dabblers have black butts in November, which makes them tricky at a distance. Gadwalls have the most black. Wigeons come in second. Northern pintails and northern shovelers have the least, though it’s usually still visible.
When you see this black butt pattern, you’re only sorting between four species. Then size, shape and field marks become more useful.
There are three merganser species in Maine. All have crests. Females don’t change much in autumn, but the males go drab. Common mergansers are largest and have the whitest breasts.
Red-breasted mergansers are midsize, with a dingy breast. They also prefer saltwater almost exclusively. Hooded mergansers are smallest, with a thick crest that makes them look blocky.
There are other tricks, but start with these. Good duck luck.
