Flyways
The Flyway Systems:
There are many routes followed by migratory birds, and while some of them can be easily traced, others are a little more complicated. No two species follow exactly the same path from beginning to end. Differences in distance traveled, in time of starting, in speed of flight, in geographical position, in the latitude of the breeding and wintering grounds and in other factors all contribute to great diversity.
The terms "migration route" and "flyway" are common terms used when talking about migration. Migration routes may be defined as the lanes of individual travel from any particular breeding ground to the winter quarters of the birds that use them. Flyways, on the other hand are broader areas in geographic region. They are wide 'roads' to which the routes are tributary.
There are four (4) major North American flyways that have been named the Atlantic, the Mississippi, the Central and the Pacific Flyways. Except along the coasts, the flyway boundaries are not always sharply defined. |
Atlantic Flyway:
The Atlantic Flyway may be described as extending from the offshore waters of the Atlantic Coast west to the Allegheny Mountains where, curving northwestward across northern West Virginia and northeastern Ohio, it continues in that direction across the prairie provinces of Canada and the Northwest Territories to the Arctic Coast of Alaska. The flyway embraces several primary migration routes and many more that are important as tributaries, some of the latter being branches from primary routes of other flyways. The Atlantic Flyway route from the northwest is of great importance to migratory waterfowl and other birds some of which are flocks of Canvasbacks, Redheads and Lesser Scaups that winter on the waters and marshes south of Delaware Bay. The coastal route of the Atlantic Flyway, which in general follows the shore line, has its northern origin in the eastern Arctic islands and the coast of Greenland. This is a regular avenue of travel, and along it are many famous points for the observation of migrating land and water birds.
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Mississippi Flyway:
This flyway is relatively simple although it presents some features of interest, chiefly as they affect the migratory waterfowl. It's eastern boundary runs through the peninsula of southern Ontario to western Lake Erie, then southwestwardly across Ohio and Indiana to the Mississippi where it rather closely follows the river to its mouth. Well timbered and watered, the entire region affords ideal conditions for the support of hosts of migrating birds. The two rivers that mark it, the Mackenzie emptying on the Arctic coast and the Mississippi in the Gulf of Mexico, have a general north-and-south direction, another factor in determining the importance of this route which is used by large numbers of ducks, geese, shorebirds, blackbirds, sparrows, warbler and thrushes,
The majority of North American land birds, seeking winter homes in the tropics, that come south through the Mississippi Flyway take the short cut across the Gulf of Mexico in preference to the longer, though presumably safer, land or island journey by way of Texas or the Antilles. During the height of migration some of the islands off the coasts of Louisiana and Texas are
wonderful observation places. |
Central Flyway:
In the United States, the Central Flyway merges toward the east with the Mississippi Flyway and bounded in that direction by the Missouri River. In the south on this side, it runs through western Missouri, Arkansas and Louisiana, and then follows the Gulf coast of Mexico southward. It may be called "the flyway of the Great Plains" as it encompasses all of that vast region lying between the valley of the Mississippi River and the Rocky Mountains, the principal wheat-growing region of both Canada and the United States. The Central Flyway is relatively simple, as the majority of the birds that use it make direct north and south journeys from breeding grounds in the North to winter quarters in the South. |
Pacific Flyway:
The Pacific Flyway includes the Arctic archipelago as Melville, Banks and Victoria islands from which region the eastern boundary tends to the southwest between Great Bear and Great Slave lakes to the western boundary of the Central Flyway along the eastern base of the Rocky Mountains in Canada. The territory of this flyway, comprises the western Arctic, including Alaska and the Aleutian Islands and the Rocky Mountain and Pacific coast regions of Canada, the United States and Mexico, south to where it becomes blended with other flyways in Central and South America.
The longest and important route of the Pacific Flyway is that originating in northeastern Alaska and passing for most, if not all, of its length through the interior. Most of the waterfowl that travel the United States section of this route come from Alaska and the Mackenzie Valley and other interior areas.
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For more information about All-Bird Conservation, contact Deb Hahn at 202/624-7890 or dhahn@fishwildlife.org. |
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