Autums arrives on the wings of waterfowl.
Tundra Swan (Cygnus columbianus), USFWS
Tundra Swan (Cygnus columbianus), USFWS

As the days shorten and temperatures drop, the Chesapeake Bay area is inundated with some 20 species of swans, geese and ducks that journey from northern breeding grounds to overwinter here or stop over on their way further south.

About 1 million waterfowl from Alaska, Canada, north central United States, and New England migrate to the rivers, creeks, and wetlands of the Chesapeake Bay in search of hospitable habitat and food critical to their survival.

Swans are the largest of waterfowl and the tundra swan travels the farthest, more than 4000 miles, to winter here. These large white birds are easily recognized by their black bills and straight necks. Tundra swans often flock together on shallow ponds.

Another swan, the mute swan, is a nonnative, invasive bird from Europe. The mute swan competes with native waterfowl for food and habitat. Orange bills and s-shaped necks distinguish the nonnative mute swan.

Canada Goose (Branta canadensis), USFWS
Canada Goose (Branta canadensis), USFWS

Autumn would not be complete without the familiar V-shaped flocks of geese in the sky. Constant honking signals the arrival of the Canada goose. A favorite quarry of hunters and bird watchers, Canada geese feed in wetlands or cultivated fields. A lesser-known visitor, the snow goose is white except for black wing tips and pink feet and bills. The small black Atlantic brant also winters here.

Ducks are characterized by their method of feeding; dabbling or diving. Dabbling ducks traditionally feed by straining food from the water's surface or by submerging their heads while their tails remain out of the water. The most common dabbler is the mallard. The male has a dark green head while the female is dusky brown. Both male and female of another dabbler, the black duck, look similar to mallard hens, only darker. These two species often interbreed. Other dabblers include the American widgeon, green-winged teal, northern pintail (male has long black tail feathers), and northern shoveler (named for its large spatula-like bill).

Northern Pintail (Anas acuta), USFWS
Northern Pintail (Anas acuta), USFWS

Diving ducks swim underwater, pursuing fish or searching the bottom for small animals, roots and seeds of Bay grasses. Diving ducks are further separated into bay ducks and sea and river ducks.

Bay ducks feed in shallow water, foraging for both plant and animal foods. Males have contrasting head and body colors while the females are dark or brown. The most distinctive is the canvasback, with its black bill, red eyes and head, and white back. Canvasbacks congregate on the water in large flocks known as rafts. Redhead ducks are similar to canvasbacks but with shorter bills and round heads. Other bay ducks include the greater and lesser scaup.

Sea ducks are commonly found in deeper, open waters of the Bay. Most sea ducks feed primarily on crabs, clams, and barnacles. The old squaw sports contrasting brown and white colors and long tail feathers. Sloping foreheads identify the white-winged, surf, and black scoter. The ruddy duck, like the canvasback, masses in rafts. The bufflehead is a small black and white duck.

The red-breasted, hooded, and common mergansers are river ducks. Mergansers prey on fish caught in fresh and brackish water. They are easily identified by long thin, serrated bills and crested heads.

Snow Goose (Chen caerulescens), USFWS
Snow Goose (Chen caerulescens), USFWS

If you don’t live on the water, however, you may never see this great variety of waterfowl. Luckily there are many National Wildlife Refuges around the Bay area. They provide great opportunities to watch and photograph waterfowl and other wildlife. So get out this fall and see the birds.