Every late autumn, winter, and early spring, I look forward to seeing a variety of migrating and/or wintering ducks, geese, and swans in southeastern Pennsylvania.

During those times, there is a variety of dabbling ducks that tip up in shallow water to feed on aquatic vegetation. And there are several species of diving ducks that dive from the water’s surface to get food near the bottoms of waterways and impoundments.

Three kinds of handsome diving ducks — buffleheads, ring-necked ducks, and hooded mergansers — commonly pass through and/or winter here. They have at least a few traits in common, including being petite and nesting around water in forests farther north.

They also prefer wintering on inland impoundments that are surrounded by woods, because of where they hatched.

These little ducks are adapted to wintering on smaller bodies of fresh water, including human-made ponds, though they have relatives that winter on salt and brackish waters.

Males of these duck species have striking feathering. Their mates are mostly brown, which camouflages them while incubating eggs and raising ducklings.

Drake buffleheads have black backs and wings, white underparts, and iridescent-green heads with a white “bonnet” on each one.

Both genders of locally wintering buffleheads spend days on impoundments of all sizes, weather permitting, where they dive for aquatic insects, crustaceans, and mollusks on the bottoms of those waters.

Buffleheads hatch ducklings in abandoned northern flicker cavities in trees by lakes in the woods of Canada and Alaska. Flickers are medium-sized woodpeckers, so female buffleheads have to squeeze into those deserted nesting hollows.

Ring-necked duck males are dark on top with light-gray sides and a vertical white bar in front of each flank. Often associating with buffleheads on the same local impoundments in winter, ring-necks dive to ingest submerged water plants, thus reducing competition for food with buffleheads.

Ring-necked hens lay their eggs on mats of emergent vegetation along the shores of lakes in the forests of Canada and New England. Ring-neck ducklings feed on aquatic invertebrates to get protein for growth.

Hooded mergansers dive under water to consume invertebrates and small fish, and they have pointed, serrated beaks to do that job. Female mergansers lay their eggs in tree cavities and nest boxes erected for them and for wood ducks in woods in the eastern United States, from southeast Canada down to the Gulf Coast.

Hoodies don’t compete with woodies for food, but they do for nesting hollows.

Both genders of hooded mergansers have crests they can raise and lower on their heads. Those crests show the ducks’ emotions and help us identify them.

These kinds of lovely, wintering ducks have certain characteristics in common, though each is a member of a different genus of ducks. They are somewhat similar because of the small impoundments they live on in wooded areas.


Clyde McMillan-Gamber is a retired Lancaster County Parks naturalist.

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