Atlantic Flyway

The Atlantic Flyway spans roughly 3,000 miles, from the Arctic breeding grounds in Greenland, Iceland, and northern Canada to the wintering areas in the Caribbean and northern South America. It encompasses the Atlantic coastal plain, including major estuaries such as Chesapeake Bay, Delaware Bay, and the Pamlico Sound, as well as offshore islands and barrier beaches. The flyway is defined by the U.S. Fish and Wildlife Service for management purposes, and it includes the Atlantic provinces of Canada, the eastern United States, and parts of the Caribbean.¹

The route is not a single narrow corridor but a broad zone, with birds using a variety of habitats, from coastal marshes to inland forests. The Appalachian Mountains form a western boundary for many species, though some birds cross them. The flyway's southern terminus is not fixed; many birds continue to the Amazon basin, while others stop in the Caribbean islands.²

The Atlantic Flyway supports a remarkable diversity of birds, including iconic species such as the Snow Goose, Canada Goose, and the endangered Red Knot. Shorebirds, such as the Semipalmated Sandpiper and the American Oystercatcher, rely on the flyway's coastal mudflats and beaches, especially Delaware Bay, which is a critical stopover for horseshoe crab eggs that fuel their migration. Waterfowl, including the American Black Duck and the Northern Pintail, winter in large numbers in the flyway's estuaries and coastal wetlands.

Songbirds, such as the Blackpoll Warbler and the Baltimore Oriole, also use the flyway, often following the coast or crossing the Atlantic Ocean directly from the northeastern United States to the Caribbean. The flyway's habitats range from boreal forests and tidal marshes to urban parks, and each supports different species at different times of the year. The National Wildlife Refuges along the coast, such as the Edwin B. Forsythe National Wildlife Refuge in New Jersey, are critical for providing resting and feeding areas.³

Conservation of the Atlantic Flyway is coordinated by the U.S. Fish and Wildlife Service and the Canadian Wildlife Service, along with state and provincial agencies. The Atlantic Flyway Council, established in 1952, develops management plans for migratory game birds, setting hunting regulations and habitat conservation priorities.¹ The North American Waterfowl Management Plan, an international agreement, also guides habitat protection and restoration efforts across the flyway.

Threats to the flyway include habitat loss due to coastal development, sea-level rise, and pollution. The Deepwater Horizon oil spill in 2010, though centered in the Gulf of Mexico, affected birds that also use the Atlantic Flyway. Climate change is altering migration timing and habitat availability, with some species shifting their ranges northward. Conservation efforts include the protection of key stopover sites, such as the Delaware Bay, and the restoration of wetlands through programs like the North American Wetlands Conservation Act.⁴

One lesser-known aspect is the flyway's role in the migration of the Arctic Tern, which travels from the Arctic to the Antarctic and back, passing through the Atlantic Flyway on its extraordinary journey. Another is the historical use of the flyway by the now-extinct Passenger Pigeon, which once migrated in enormous flocks along the coast. The flyway also includes a significant overwater leg: many birds, such as the Blackpoll Warbler, fly nonstop from the northeastern United States to the Caribbean, a journey of up to 2,000 miles.⁵

In addition, the flyway is a key route for the migration of the Monarch butterfly, which is not a bird but uses the same coastal corridors. The flyway's importance extends to human culture: it has influenced the location of birdwatching festivals, such as the Cape May Autumn Birding Festival, and the development of birding tourism. The flyway also has a military connection: during World War II, radar operators noticed bird migrations on their screens, leading to the study of bird migration and the establishment of the U.S. Navy's bird strike prevention programs.

Flyway

A geographic route used by migratory birds between breeding and wintering grounds.

Stopover

A resting and feeding site used by migratory birds during their journey.

Horseshoe crab

A marine arthropod whose eggs are a critical food source for migrating shorebirds.