INFL

Showing posts with label Aythya valisineria. Show all posts
Showing posts with label Aythya valisineria. Show all posts

Friday, April 19, 2013

Canvasback


Canvasback

 
Aythya valisineria


canvasback-diver-duck.jpg
Canvasbacks are diver ducks well equipped with their own form of flippers—large webbed feet that make them smooth and graceful swimmers.
Photograph by Jac6.Flickr, Flickr
Canvasbacks are diver ducks well equipped with their own form of flippers—large webbed feet that make them smooth and graceful swimmers. They spend much of their time in the water and use their long bills to feed by digging through bottom sediments in search of aquatic plant stems and roots, or submerged insects, crustaceans, and clams.
On land, canvasback movements are clumsy and the ducks seldom stray too far from the water’s edge. But when “cans” take to the air they can cover a lot of ground.
Each year when winter weather begins to chill northern lakes, ponds, and prairie wetlands, the canvasbacks’ food becomes scarce and the ducks take flight in enormous flocks. Thousands of birds migrate together each year to traditional wintering sites like the Chesapeake Bay, San Francisco Bay, Gulf Coast, and Mexico. The majority of North American canvasbacks breed in the Prairie Pothole wetlands and migrate via the Mississippi Flyway to the Mid-Atlantic and Lower Mississippi Alluvial Valley, or along the Pacific Flyway to the California coast.
The Chesapeake Bay’s Susquehanna Flats area was once the winter home of perhaps half of the North American canvasback population. But the shoals’ lush beds of wild celery have declined with compromised water quality and increased sedimentation. Chesapeake canvasback numbers followed suit and have declined some 80 percent over the last 50 years.