Every fall, a great migration begins as thousands of swans, geese and ducks leave northern breeding grounds and begin flying south.

The Chesapeake watershed lures these birds from Alaska, Canada, the Northcentral United States and New England as they seek out the open water of the Bay, its rivers and wetlands for habitat and food critical to their survival.

About a third of all waterfowl that winter on the Atlantic Coast do it right here. You may not realize just how many different types of wintering visitors we get. If, like me, you live in a suburban area away from water, you may only see mallard ducks and Canada geese. But check out a park or wildlife refuge this winter and you’ll be surprised by the vast variety.

Swans are the largest of waterfowl and the tundra swan travels the farthest — more than 4,000 miles — to winter primarily on the Delmarva Peninsula. 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 an invasive, nonnative bird from Europe. The mute swan competes with other waterfowl for food and habitat. Orange bills and s-shaped necks distinguish the invading mute swan from our native tundra swan.

Constant honking signals the arrival of the familiar Canada goose, with its black-and-white head, brown back and pale breast. A favorite quarry of hunters and birders, Canada geese feed in wetlands and farm fields. But keep your eye out for a lesser known visitor, the snow goose, easily distinguished by its white body, black wing tips and pink feet and bills.

The greatest diversity of wintering waterfowl is found in the many duck species. Ducks are often characterized by their feeding methods: dabbling or diving. Dabbling ducks feed by straining food from the water’s surface or by submerging their heads while their tails remain out of the water. Males are usually brightly colored while females are drab. Plants make up most of the dabblers’ diets. Dabblers take flight by leaping from the surface of the water and can be found on rivers and close to shorelines.

The most commonly recognized dabbler is the mallard duck. The male has a dark green head while the female is dusky brown.

Another dabbler is the American black duck. Both male and female American black ducks look similar to mallard hens, only darker. These two species often interbreed. Other dabblers include the American wigeon, green-winged teal, northern pintail (male has long black tail feathers), and northern shoveler (named for its large spatula-like bill).

Diving ducks have legs located to the rear of the body. This makes walking on land difficult. Diving ducks swim underwater, pursuing fish or searching the bottom for small animals and the roots and seeds of Bay grasses. They must run along the surface of the water to take flight. Diving ducks can be further separated into bay, sea and river ducks.

Bay ducks feed in shallow water, foraging for both plants and animals. Males have contrasting head and body colors while the females are dark or brown. The most famous is the canvasback, with its sloping black bill, red eyes and head, and white back. Canvasbacks congregate on the water in large flocks known as rafts. Other bay ducks include the greater and lesser scaups.

Sea ducks are commonly found in the deeper open water of the Bay. Most sea ducks feed primarily on animals like crabs, clams and barnacles. The long-tailed duck sports contrasting brown and white colors and long tail feathers. Sloping foreheads identify the white-winged, surf and black scoters. The bufflehead is a small black and white duck. Like its name implies, the male of this duck has an easily identified puffy head.

The three species of river ducks are all mergansers. The mergansers prey on fish caught in fresh and brackish water. Mergansers are identified by long thin serrated bills and crested heads. The red-breasted, hooded and common mergansers overwinter in the Chesapeake Bay area.

Where to Watch for Waterfowl

Nearby National Wildlife Refuges provide some of the best opportunities to see a variety of wintering waterfowl. Consider visiting one as part of your winter plans this season.

  • Bombay Hook National Wildlife Refuge: Smyrna, DE. 302-653-6872, fws.gov/refuge/bombay_hook/
  • Prime Hook National Wildlife Refuge: Milton, DE. 302-684-8419, fws.gov/refuge/prime_hook/
  • Blackwater National Wildlife Refuge: Cambridge, MD. 410-228-2267, fws.gov/refuge/blackwater
  • Eastern Neck National Wildlife Refuge: Rock Hall, MD. 410-639-7056, fws.gov/refuge/eastern_neck
  • Patuxent National Wildlife Refuge: Laurel, MD. 301-497-5580, fws.gov/refuge/patuxent
  • John Heinz National Wildlife Refuge at Tinicum: Philadelphia. 215-365-3118, fws.gov/refuge/john_heinz
  • Back Bay National Wildlife Refuge: Virginia Beach. 757-721-2412, fws.gov/refuge/back_bay
  • Chincoteague National Wildlife Refuge: Chincoteague, VA. 757-336-6122, fws.gov/refuge/chincoteague/
  • Eastern Shore of Virginia National Wildlife Refuge: Cape Charles, VA. 757-331-2760, fws.gov/refuge/eastern_shore_of_virginia/
  • Elizabeth Hartwell Mason Neck National Wildlife Refuge: Lorton, VA. 703-490-4979, fws.gov/refuge/mason_neck/
  • Great Dismal Swamp: Suffolk, VA. 757-986-3705, fws.gov/refuge/great_dismal_swamp
  • James River National Wildlife Refuge: Hopewell, VA. 804-829-9020, fws.gov/refuge/james_river/. Advanced reservations required.
  • Occoquan Bay National Wildlife Refuge: Woodbridge, VA. 703-490-4979, fws.gov/refuge/occoquan_bay/
  • Rappahannock River Valley National Wildlife Refuge Complex: Warsaw, VA. 804-333-1470 x1, fws.gov/refuge/rappahannock_river_valley/