Winter Visitors Arrive

Trumpeter Swans again feeding in the fields

 

Trumpeter Swan in flight

© 2008 R. Pera

The changing season heralds the return of the magnificent Trumpeter swans to Puget Sound in northwest Washington.  Small flocks of swans are being seen along the I-5 corridor, north to Whatcom County and the Canadian Border, and south into Snohomish County.

Large regions in central Alaska are summer breeding grounds for Trumpeters.  In the autumn, as these areas begin to freeze over, the swans start their annual fall migration.  The freeze-thaw conditions are a signal for groups of swans to gather together.  They arrive down here at historical roost sites as families and as extended families.  These families include sub-adults, adults and adults with juvenile swans.  They jump from Alaska, down to the lower British Columbia and Washington.  Also, they will eat in one area and roost in another, so they move around all the time.   When they first arrive, they continually move from one location to another.  Biologists believe that this movement allows time for extended families to catch up with those members lost during the migration.  After December, they settle into traditional feeding and roosting sights.  The northerly spring migration starts when their body weight increases and sunlight starts photosynthesis in the vegetation.

An estimated 3,846(1) swans from the central Alaska population winter in Skagit County, the Bellingham area and Padilla Bay.  During the day they are seen feeding on upland grasses and waste grain in the fallow agricultural fields. After the weather freezes, and when they can find them, they enjoy cultivated tubers such as sweet potatoes and white potatoes (carrots and turnips, too).  They also feed while swimming in local waters and can be seen up-ending or dabbling to reach submerged aquatic plants. 

Trumpeter swans are named for their trumpet-like honk, which has been compared to a French horn and maybe heard for up to a mile away.  The best time to hear them calling is in the early morning or at dusk as they fly in small ‘V’ formation flocks to and from estuaries, fresh water ponds and interior lakes where they spend the night.

 

Trumpeter Swan standing

@ 2008 Ron Pera

They are the largest North America waterfowl, if measured in terms of weight and length, and are the largest swan in the world.  The male swan, called a cob, ranges in length from 57 to 64 inches and weighs between 26 to 35 pounds.  The female, called a pen, is smaller with a length of 55 to 60 inches, and weights 22 to 28 pounds.  The wingspan of the average male is 6 to 8 feet.  However, an exceptionally large cob can have a wingspan of 10 feet.

The plumage in both sexes is snowy white; the short legs and webbed feet are black.  They have long slender necks with bills that are black with a subtle salmon-pink mark along the lower mandible.  If you look closely, some of the swans in the fields have rusty colored necks and heads.  This coloration is caused from feeding in ferrous (containing iron) waters.  The juveniles, called cygnets, have sooty gray plumage, their feathers becoming white after the first year.

Hunted to near extinction, by 1940 there were only 69 swans south of the US-Canada border, with a small population discovered in Alaska.  Over the past half-century, through many conservation efforts these splendid swans are slowly recovering and re-occupying areas they have not been found in for decades.  Today, the Alaska population is approximately 13,000 swans.

However, our Trumpeter swans face another threat.  This is in the form of lead poisoning from ingesting remnant lead shot found in their feeding areas.  Since 1999 an average of 306(2) swans die annually in Sumas, Canada, Whatcom, Skagit and Snohomish Counties.  Lead shot for waterfowl hunting was banned in Washington in 1989 and in Sumas Prairie Canada in 1992.  The concern for the swans is the residual and accumulative shot left in the fields (prior to the ban) where they feed and on their traditional roosting sights. 

A working group comprised of Canadian Wildlife Service, Washington Department of Fish and Wildlife, U.S Fish and Wildlife Service, Trumpeter Swan Society, and University of Washington have been working since 2001 to locate the sources of lead shot and end, or minimize, swan mortalities.  A successful hazing program around Judson Lake, one of the lead poisoning source areas, seems to have reduced lead-caused swan mortalities around that lake(3). 

While this is a good start to eliminating lead-poison mortalities in swans more needs to be done in the future if we are to continue enjoying these majestic Trumpeter swans each winter.

The Washington Department of Fish and Wildlife hotline to report dead or dying swans is (360) 466-4345 ext: 266.

  1. Figure from 2007(8) National Audubon Christmas Bird Count
  2. U.S Fish and Wildlife Service: “Swan Lead Poisoning Information Sheet 2007-2008 Progress Report” 
  3. U.S Fish and Wildlife Service: “Trumpeter Swan Population Status 2000”

 

Written by Sheila Pera

Beach Watcher Class ’03

 

Published December 2008

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