Flyways are heavily traveled routes bird use during migration.
Wherever humans live they discover the natural patterns and rhythms of the land. Indigenous peoples knew which areas birds congregate at during their annual migrations. These gathering places were prime hunting locations.
In the 1930’s western scientists and investigators became impressed by what appeared to be four broad, heavily traveled “highways” in North America. This concept was based on several thousand records of migratory waterfowl. The “highways” were only approximate and many birds migrate outside of them.
W.W. Cook identified seven generalized routes for birds leaving the United States on their way to various wintering grounds (see map above). The routes by which birds return northward in the spring are not as well-known.
During migration, birds tend to follow physical features such as coastlines, mountain ranges and river valleys. Birds that don’t fly over the open ocean in their migrations, tend to use the same overland routes during both north (spring) and southward (fall) migrations.
Variations in where birds fly over depends on weather patterns, en route resources and the geographical features that bird encounter.
Why Do We Study Bird Migration Routes?
The “flyways” concept helps humans to coordinate our efforts to protect areas important to birds for their migrations. In the United States, National Wildlife Refuges are strategically placed along bird migration routes to provide safe places for birds to land, refuel, and rest.
Main Bird Migration Routes in North America
Look over the following list and the map above to see if you live on or near a fall bird migration route. The seven flyways are located within the four larger geographical areas.
Atlantic Oceanic Route (route 1)
This route mostly travels across the Atlantic Ocean. It stretches from Labrador and Nova Scotia to the Lesser Antilles, then through a small group of islands to the mainland of South America. Since this route is almost entirely over water, the only way humans know about it, is through observations on islands like Bermuda and those islands along the way. Birds usually fly this route by both day and night.
Atlantic Coast Route and Tributaries (route 2)
The Atlantic coastline is a regular route of travel. It has many famous birding hotspots for observing both land and water birds. About 50 different kinds of land birds that breed in New England follow the coast southward to Florida and travel by island and mainland to South America. At no time are these air travelers out of sight of land. It is not however the favored migration highway. Only about 25 species of birds use this route to go to their winter homes beyond Cuba to Puerto Rico. This was known as the Atlantic Flyway. This is the route that covers the sky over Philadelphia, Delaware and the Jersey Shore.
Mackenzie Valley-Great Lakes – Mississippi Valley Routes and Tributaries (route 3)
Some routes in this flyway have been renamed.
This bird migration route is the longest of any in the Western Hemisphere. It extends from the Mackenzie Valley past the Great Lakes and down to the Mississippi valley. Its northern end is on the arctic coast in the regions of Kotzebue Sound, Alaska and the mouth of the Mackenzie River. The southern end lies in Argentina.For more than 3,000 miles, from the mouth of the Mackenzie to the Mississippi delta, this route is uninterrupted by mountains. Because it has plenty of trees and water, the area is a great place to view great numbers of migrating birds.
During the height of migration, going to birding hotspots in the Mississippi Valley, allow birders to can see large numbers of many species. Swarms of birds are spotted on the islands off the coast of Louisiana. This was known as the old Mississippi Flyway. (route 4)
This route begins in the Mackenzie River delta in Alaska. Some places in this area, such as the National Bison range at Moise, Montana, have food in such abundance that birds stop here during migration to refuel. This was known as the old Central Flyway.
The Pacific Coast Route (route 5)
This bird migration route is not as long or heavily traveled as some of the others. Because of the nice living conditions, many species of birds breeding along the coast from the northwestern states up to southeastern Alaska either do not migrate or else make short journeys. This route has its origin chiefly in Western Alaska around the Yukon river delta. Large numbers of arctic-breeding shorebirds also use this route. This was known as the old Pacific Flyway.
Pacific Oceanic Route (route 6)
This route is mainly over water. It extends from the islands of the Bering Strait through the islands of the central Pacific and northward along the Asiatic Coast. Many seabirds that breed in the far northern coasts, southern coasts and islands migrate across the Pacific away from land and except when the breeding season approaches. Incredibly, birds navigate to tiny isolated islands in the middle of the vast Pacific Ocean.
Arctic routes (route 7)
Some arctic nesting birds travel only a short distance south in winter. They fly mainly along the coast. The best defined arctic route in North America follows the coast of Alaska.
Sources: Information courtesy of: “Migration of Birds: Routes of Migration”,http://www.npwrc.usgs.gov/resource/birds/migratio/routes.htm March 09, 2007.More Bird Migration Information
More Bird Migration Routes Information
Fall Bird Migration Hotspots – National Wildlife Refuges
National WIldlife Refuges (NWR) are strategically placed along major bird migration routes. They are excellent places to see fall bird migration. See the NWR list of best places.
Cape May National Wildlife Refuge, Cape May, New Jersey (FWS.org)
Bear River Migratory Bird Refuge National Wildlife Refuge, Utah (FWS.org)
Horicon National Wildlife Refuge, Wisconsin (FWS.org)