Keeping a watch on Trumpeter Swans

Posted: Friday, October 06, 2000

October is the best month to see wild North American swans in Southeast Alaska.

The Trumpeter Swan is the heaviest bird in North America and, perhaps, the heaviest flying bird in the world, something reaching 40 pounds.

Trumpeters once nested across mid North America, but as agriculture progressed across the continent they were exterminated. In the 1930's less than 100 could be found, a small population in the vicinity of Yellowstone National Park. We now know a few survived in Alberta and in the Boreal Forest of Alaska.

Alaska Trumpeters have increased from about 3,000 in 1968 to over 20,000 this year. Trumpeters nest in the rain forest too, near Cordova, Yakutat and Haines, and more recently at Berners Bay, Taku River and Whiting River.

It is thought our Trumpeters declined greatly as the estuaries of western British Columbia and Washington, where they wintered, were converted for log rafting, navigation, flood control and waste disposal. The swans learned to eat waste from products such as grains, potatoes and carrots in the fall and new grasses early in the year. This rich food enabled them to return north in peak nesting condition and produce large families.

A few Trumpeters do winter in Southeast on natural habitat generally in groups of less than 100. Cordova, Yakutat, Petersburg and perhaps other places have regular wintering flocks where people can see them. Others are remote and seldom seen.

Alaska Trumpeters and some from the Yellowstone have been used to reestablish nesting populations in South Dakota, Minnesota, Wisconsin, Michigan, Iowa, Ohio and Ontario. Eighty percent of the world population of Trumpeters still nest in Alaska.

Tundra Swans also suffered during the freewheeling hunting days of the 19th and early 20th centuries. But farming never reached their far north nesting range so they were able to survive in larger numbers. They have been increasing slowly since the protection afforded by our 1916 Migratory Bird Treaty with Canada and now number about 230,000 with a little over half nesting in Alaska.

The western populations nests primarily from the Bristol Bay lowlands to the river valleys of Kotzebue Sound, and use migration routes on both sides of the Coast Range to reach their winter home in California's Central Valley. They too are sustained by agricultural waste, particularly rice.

An eastern population of Tundras that nest from Alaska's North Slope to Hudson's Bay in Canada winter from Maryland to North Carolina.

Sometimes we see migrant flocks containing both Trumpeters and Tundras. Then they can be easily identified because of the greater size and deeper voice of the Trumpeters. More often they are separate and it is harder to identify them unless you know the call or can see the little yellow spot on the otherwise black bill of the adult Tundra Swans.

The first-year young of these swans always appear gray when not flying, although in flight their underside is quite white. Swans normally migrate in family groups and even in a large flock an observer can often pick out one or rarely as many as nine gray young with their two white parents in close attendance.

Trumpeters often migrate as a single or several families. They tend to fly lower and stop more often than the Tundras. So seeing a Trumpeter family on any lake in Southeast during fall or spring migration is a possibility.

Tundra Swans are more often in long lines or wedges high above communicating with their more flute-like than trumpet-like call. They prefer clear or broken skies and a tail wind. Sometimes we can see flock after flock go over, hundreds of birds in an hour and thousands of tens of thousands in a day. If the moon is bright one can even see as well as hear them at night. As weather varies every year so to does the migration pattern.

If low ceilings and southeast winds persist the Tundra Swans flocks may have to stop for the night or sometimes a day or two in a shallow bay or larger lake.

When the weather patterns are adverse the weaker youngsters may drop out. Orphan swans are vulnerable, but if they can find good feed they may get their strength back and proceed perhaps finding other late migrants.

Juneau Audubon Society is sponsoring a field trip to Petersburg Nov. 4-5 to view Trumpeter Swans at Blind Slough. For further information contact Judy Shuler at 789-9544. Members of the Juneau Raptor Center will present the monthly program beginning 7:30 p.m. Oct. 12 in Dzantik'i Heeni Middle School Library.

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