Waterfowl Migration in Autumn

wood duck Aix sponsa — Wood Duck (Aix sponsa) on the Wissahickon Creek.

Waterfowl fly south as cold weather approaches. As the cold temperatures take hold waterways such as ponds, lakes, river and streams become partially or completely covered with ice. Ducks and geese which depend on the open unfrozen water to find food would struggle to survive. They must move where waters are still unfrozen and food is still readily available. The great waterfowl migration south begins.

Duck Hunting in the Eastern Woodlands

Birds that breed in the far north in the cold and tundra areas of North American fly southward to winter along the coastal waterways. Heavy concentration of ducks are found up and down the east coast waterways, particularly freshwater or saltwater marshes, ponds, lakes, rivers, streams, fens, bogs, bays and inlets.

The spring and fall migrations of waterfowl such as ducks and geese were a time of plenty for indigenous and other hunters. The birds overwinter in vast numbers in their wintering grounds.

The waterways of the Tidewater and Chesapeake Bay areas, are key destinations for migrating waterfowls such as Snow Geese, Green-winged Teal, Northern Shoveler, and Canvas back ducks. In fall after the agricultural harvest had been gathered and preserved for winter eating, hunting of migratory waterfowl takes place.

Rappahannock hunters of Tidewater Chesapeake Bay area, hunt waterfowl during the fall migration. The hunters would leave a trail of seeds from the water’s edge further into the bush. The birds follow the trail and eat the seeds. The hunter wouldn’t trap the birds on that first day. The second day the procedure was the same but the birds would be caught this time. If a local resident bird, such as a cardinal was caught in the trap instead of waterfowl, the hunter would release the local bird. This custom not to trap local birds but only ‘stranger’ birds which were passing through on migration. This custom benefited the continued workings of the local ecosystem.

Molting: Preparing to Migrate

Before migrating, ducks molt their feathers. some species lose all their feathers including flight feathers. Flight feathers may take up to five weeks to grow back. At this flightless time, the birds are vulnerable. Female ducks loose some of their feathers before breeding and nest sitting. They molt the rest of their feathers after the breeding season is over and before migration to wintering areas. Male ducks undergo a complete molt, losing all wing feathers, before migration.

bird female mallard duck — Female Mallard Duck (Anas platyrhynchos).

What Triggers Autumn Duck Migration?

The day length (photoperiod) shortens as autumn approaches. Waterfowl know they will need to move south to warmer temperatures, open water, and more abundant food. Like many of Earth’s organisms, birds can sense the shortening of day length.

In northern latitudes such as arctic tundra, and frigid winter areas of Turtle Island (North America) food plants stop growing and producing seeds, insects and tadpoles hibernate, and worms and crustaceans dig deeper into the mud.

Autumn waterfowl migrate south when weather conditions consist of north to northwest winds, falling temperatures and high-pressure systems.

bird duck male mallard — Male Mallard Duck (Anas platyrhychos).

Time of Day and Waterfowl Migration

Each species has their preference of when during the day or night they migrate. Canada Geese migrate during the day which is known to anyone who has listened to their honking calls as the fly overhead during the day. Snow Geese migrate during the day or night. The Dabbling duck species and pochards migrate typically at night.

Migration Along Flyways

As the days shorten waterfowl begin putting on weight, storing fat on their body as fuel for long flights. The birds feed heavily during migration to have the energy to complete their journeys. Many waterfowl use predictable routes during their fall migration. Humans refer to these routes as flyways.

Flyways are predictable routes used by migrating birds along waterways, valleys, and ridges. Along these routes birders enjoy watching the spectacle of fall migration. Most waterfowl migrate.

Geese honk while flying to encourage each other to stay in a V-formation during flight. Honking is also a method flock members use to communicate.

Geese have been reported to fly at very high altitudes during migration. They have been spotted move over land at altitudes of 1,000 to 5,000 feet. Birds have been observed even higher at 20,000 to 27,000 feet. Once when I was flying to Las Vegas a Snow Goose was flying right beside the plane. Our eyes meet as the bird was passed by the fast-moving jet.

How Far Can a Duck Migrate in a Day?

Whether ducks, geese and swans migrate and how far is determined by the availability of food and open water. Some birds travel thousands of miles and others less than one hundred.

Migrating Waterfowl

Not all waterfowl migrate. Those species that live in relatively mild climates may stay all year round in those areas. But they have to make do with the food availability instead to flying to better food areas.