Ducks are back in the landscape
In October, two groups welcome the sound of wings over the waters of our land: birders and duck hunters. The sight of the brightly-colored drakes and their duller-plumaged hens floating on wooded streams, flowing rivers and marshy ponds lifts our spirits.
While most people know at least the common mallard, they might be interested to know that there are four tribes of true ducks: dabbling ducks, bay ducks, sea ducks and stifftails. In the family of dabbling ducks belongs the mallard, as well as 11 other species that are native to North America.
This is the group we will explore in this article.
As do all ducks, dabbling ducks sport large, webbed feet to propel themselves through the water. Although the water may get cold, they have a physiological hack that shunts warm blood from the body into the returning cold blood to prevent the duck from suffering hypothermia.
The bills of the ducks are broad and fairly flat, with strainer-like structures called lamellae that aid in their feeding from the water’s surface or muddy bottom. An extreme example of the typical bill belongs to the Northern shoveler, which stirs up the bottom mud and swings its bill side-to-side, straining the water through its lamellae.
As is probably obvious from the name, dabbling ducks feed on water plants and invertebrates in shallow water. We often see just their tails, bottoms and feet when their heads are pointed down into the water. They also feed on the surface by straining water through their bills and forage for seeds and plants on land.
Wood ducks can be seen competing with squirrels for acorns. Unlike the three other tribes of ducks, dabbling ducks do not dive for their food.
Where are these ducks in the summer? Why do they disappear from our waterways? After breeding in the spring, drakes leave their mates to hatch and care for the young ducklings, while they fly off to a secluded, food-rich waterway. There they lose their flight feathers all at once, becoming vulnerable to predators.
They go through a molt into drab eclipse plumage that helps camouflage them, so they look much like female ducks from midsummer to fall. In the fall, when the water freezes, they fly to their wintering grounds, where they molt again into the plumage that we recognize (and the hens love). They display their bright new feathers and pair up in the winter.
Ducks lay 3-14 eggs, many in nests on the ground (mallards, gadwalls and blue-winged teals, for example). Mallards and pintails often nest on the ground in agricultural fields, where the nests are prone to destruction in farming operations. The handsome wood duck finds a hole where a tree branch has fallen off, usually 30-60 feet above the ground
It seems quite strange to see a pair of wood ducks standing together in a high tree. Their downy ducklings, soon after hatching, climb out of the nest and launch themselves into the air, falling with a soft thud on the ground below. They quickly make it to the water to join their mother and are fully capable of swimming and feeding themselves.
Despite the precocious behavior of the ducklings and large number of hatchlings, in general the nesting success in ducks is quite low. Ducklings are favorite meals of many predators on land, air and water, from hawks and eagles to minks, skunks and foxes to snapping turtles.
Duck populations are also affected by habitat loss. Duck hunting does not seem to affect duck populations, at least negatively, as organizations such as Ducks Unlimited work to restore and protect wetland habitat for ducks. This year, in fact, DU reported they had preserved one million acres of duck habitat, working with local landowners and state organizations.
Another challenge for waterfowl is a rise in the incidence of the highly pathogenic avian influenza virus (bird flu). This highly contagious virus affects domestic poultry and wild birds, causing loss of coordination, swimming or walking in circles, inability to fly, and a twisted neck, leading to death.
Although its effects on domestic poultry have been devastating — 99 million commercial and backyard poultry have been affected — scientists do not expect the virus to have long-term effects on waterfowl populations.
With all the challenges these ducks face, it is wonderful to see them repopulating our streams, rivers and lakes in the fall and winter. Take time to go outside and take a good look at our amazing waterfowl.
Kay Cramer is editor of Bird Lore and past president of Seven Mountains Audubon in Lewisburg. Her favorite birding spot is her own farm in southern Snyder County.