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Migration 2000  

Migration Offers Navigation Challenges

Ducks Unlimited Canada National Head Office, Oak Hammock Marsh, Man., September 20, 2000-Ducks Unlimited says we can gear up for another awe-inspiring migration. Ninety million ducks are expected to wing their way south this year according to estimates released by the United States Fish and Wildlife Service, the coordinating body of waterfowl surveys in Canada and the United States. This year's fall migration is tied with that of 1997 for the second highest migration on record following last year's record-breaking estimate of 105 million birds. Migration of geese is expected to be comparable to last year's good numbers.

While migration is the greatest journey undertaken by waterfowl, no maps are marked for the trip. The birds will follow migration paths passed on from one generation to the next. According to Brian Gray, Ducks Unlimited's director of conservation programs, migration watchers are also taking part in a time-honored tradition. Bird migrations are very much a part of human history.

"Human admiration of birds' biannual travels is not misplaced. Research by biologists throughout the centuries has repeatedly identified how in-tune birds are with their environments," Gray said. Today, biologists believe birds' migratory journeys are guided by a combination of elements including the stars, sun, the Earth's magnetic field and geographic landmarks.

"Of all the navigational tools used by waterfowl, geography is where the greatest changes occur from one migration to the next," Gray said.

Changes in geography, which usually result in habitat loss, are challenging to birds that rely on the same habitats year after year. Along the pathways of some migratory birds, especially shorebirds, are key wetland rest stops called staging areas where birds eat to regain energy and rest for the next part of the journey. When key habitats are lost to development, migrants are hard pressed to find alternatives. Wintering ground habitats are also important. Recent harlequin duck research on British Columbia's coastal wintering grounds has shown that bonds between males and females are retained for many years because the birds meet and re-pair at the same point every winter.

Habitat loss also impacts migrating waterfowl that return in the spring. At this time, certain female ducks like mallard and canvasback hens, lead their mates back to the area where the females were raised. It's a waterfowl tradition that Gray says can help to increase a hen's chance of raising a brood.

"The hens benefit because they're familiar with their surroundings and can make optimal use of resources. If their habitat is gone, the birds expend energy searching for new habitats or the hen ends up nesting in suboptimal conditions," Gray said. Wetlands used by migratory birds range from seasonally flooded areas to larger wetlands but they all have an important place when it comes to waterfowl migrations and life cycle needs of a variety of wildlife species. Ducks Unlimited is working with landowners across Canada to develop land management plans that will ensure both wildlife and people can continue to benefit from the country's wetlands and associated habitats.

Wetlands benefit people by filtering impurities from water and they moderate the impacts of floods and droughts. Ducks Unlimited Canada is a private, non-profit organization dedicated to the conservation of wetlands and associated habitats for waterfowl, other wildlife and people.

 
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