The objectives of the Shorebird Migration Program have been 1) to describe the routes that individual shorebirds take in migrating from wintering areas to breeding grounds; (2) to determine if timing and routes of spring migratory shorebirds vary among years; (3) to estimate for how long birds stop at sites during migration and to determine what variables affect stopover duration; and (4) to compare strategies of different species.

 

More than 340 Western Sandpipers (Calidris mauri) have been radio-tagged during 5 spring seasons.  In 2001 the program radiotagged 3 species of shorebirds that had never been tracked over long distances during spring migration:  Dunlin (C.alpina pacifica), Long-billed Dowitcher (Limnodromus scolopaceus), and Short-billed Dowitcher (L. griseus caurinus).  We have found that during spring migration shorebirds alter their behavior and physiology.  As birds move northward they stay shorter periods of time at stopovers.  And, the later the date, the shorter the stay.  At the same time, shorebirds will travel faster the closer they get to their breeding grounds and deposit fat faster.  The cooperative research has also shown repeatedly that along the Pacific Flyway, the intertidal mudflats of the Copper River Delta provide the most significant known stopover site for the Western Sandpiper, Dunlin, Long-billed Dowitcher and the Short-billed Dowitcher.

The Pacific Flyway Shorebird Migration Program

Co-Principal Investigators

Mary Anne Bishop, Ph.D., Prince William Sound Science Center, mbishop@pwssc.org

John Takekawa, Ph.D., US Geological Survey, San Francisco Bay Estuary Field Station

Nils Warnock, Ph.D., PRBO Conservation Science

Tony Williams, Ph.D., Simon Fraser University

 

Funding

US Fish and Wildlife Service, USDA Forest Service, Canadian Wildlife Service, Alaska Department of Fish and Game Nongame Program, Chase Wildlife Foundation, Skaggs Foundation, Grays Harbor Audubon Society, Moore Foundation, National Fish and Wildlife Foundation, Goldman Fund, Ducks Unlimited, Pacific Coast Joint Venture

And the over 70 collaborators who have helped us in numerous ways

 

Recent Publications:

Williams, T.D., N. Warnock, J. Y. Takekawa, and M.A. Bishop.  2007.  Flyway Scale Variation in Plasma Triglyceride Levels as an Index of Refueling Rate in Spring-Migrating Western Sandpipers (Calidris mauri).  Auk 124(3):  886-897.

Bishop, M. A., N. Warnock, and J. Y. Takekawa.  2006. Spring Migration Patterns in Western Sandpipers Calidris mauri.   Pages 545-550 in G.C. Boere, C.A. Galbraith, and D.A. Stroud (eds.), Waterbirds around the world.  The Stationery Office, Edinburgh, U.K.

Bishop, M.A., N. Warnock, and J. Takekawa.  2004.  Differential spring migration of male and female Western Sandpipers at interior and coastal stopover sites. Ardea 92:185-196.

Warnock, N., J.Y. Takekawa, and M.A. Bishop.  2004.  Migration and stopover strategies of individual Dunlin along the Pacific Flyway.  Canadian Journal Zoology 82:1687-1697.

The Pacific Flyway is the corridor which birds pass through en route to their central Canadian and Alaskan breeding grounds. For many species of shorebirds, certain coastal routes and areas are consistently used during migration because of winds patterns, available habitat, and an abundance of prey. 

 

Since 1995, the Pacific Flyway Shorebird Migration Program has begun to reveal how individual Western Sandpipers (the most numerous shorebird on the Pacific Flyway) and other shorebirds migrate from Mexico north to their breeding grounds in Alaska.  By attaching small (<2 grams) radio-transmitters to birds on their wintering and at their stopover areas, we have been able to track birds over long-distances.  Dr. Mary Anne Bishop at the Prince William Sound Science Center has been one of the co-Principal Investigators on this long-term study.

The Copper River, 30 miles east of Cordova, emptying into the Gulf of Alaska, shown here in color infrared imagery from NASA.

Long-billed Dowitcher fitted with a lightweight radio tag