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Before European settlement, as many as 150,000 trumpeter swans lived in the Eastern United States. By the end of the 19th century, they were all dead, victims of pioneer settlers who wanted their meat, or hat-makers who wanted their feathers. (Hatters played a major role in conservation: their use of feathers from the great blue heron and the bald eagle helped spark the formation of the Audubon Society and the passage of laws protecting migratory birds.)
Today, 36 nesting pairs of the ghostly trumpeter swans grace the marshes of northern and central Wisconsin, courtesy of a program that began brining the birds home more than 10 years ago. The population has doubled in the past two years, according to Sumner Matteson, an avian ecologist with the Wisconsin Department of Natural Resources (DNR) who works on the reintroduction project.
When the streams, lakes and marshes of the Eastern United States lost the trumpeter swan, they lost a majestic bird with snowy white feathers whose bills, legs and feet are trimmed in jet black. With a wingspan between 7 and 8 feet, the swan is the largest waterfowl in the United States; males can weigh 35 pounds.
"It's an absolutely stunning sight, on a fall morning, in the fog, to see this pure white bird with its black bill," says Matteson. "In these still mornings, it has one of the most haunting calls you'll ever hear."
After two years of false starts, DNR biologists began collecting eggs in Alaska in 1989. The swan's historic breeding range extends in a wide band from the Bering Sea east through most of Canada and south to Missouri, Illinois, and Indiana. The Alaska population was healthy, and removing 50 eggs per year caused no harm.
The eggs were incubated and hatched at the Milwaukee County Zoo. From there, cygnets -- young swans -- went into one of two programs:
Captive rearing
Cygnets were raised in pens on the shore of a pond for 12 weeks. Then they were allowed to roam the entire pond with some flight feathers removed to prevent them from taking wing. After two years on the pond, they were transported to wetlands in northern Wisconsin and released.Decoy rearing
Five days after hatching, cygnets were flown to the wetlands, separated into groups of up to 10, and tended for the summer by University of Wisconsin-Madison undergraduate interns. The interns sat inside a blind mounted on an inner tube and tied to a swan decoy and ushered the cygnets to feeding spots. If a great horned owl, coyote, fox, bear or human appeared, the interns played a warning sound on a hidden tape recorder. Matteson says the birds must be taught to fear predators.
Soggy
but satisfying: In return for wading around all summer long, wildlife
ecology students inside this blind-decoy contraption got to watch a marsh
up close and personal while "baby-sitting" groups of cygnets. Goal: to
teach cygnets to recognize food, fear danger, and respond to the "follow
me" call. Courtesy Sumner Matteson.
Given the recent successes, Matteson expects the population to continue growing, and to reach perhaps 50 pairs in state. The exact goal will be determined by a computer program that hasn't yet been run.
Despite the success, problems remain. The majestic swans are being poisoned from eating lead shot pellets, which still pollute the bottom of wetlands even years after being banned. Just a pellet or two, Matteson says, is enough to kill a swan, or sicken it enough to be easy prey for predators. As old pellets oxidize, they become more toxic, so the "problem will always be with us."
And hunters continue to shoot swans, either because they don't know that the bird is protected by federal law, they can't recognize them. (The only white waterbird that might be mistaken for a trumpeter swan is a snow goose, which is less than half the size. Snow geese have black wing feathers; the trumpeter swan's feathers are solid white.) The birds winter in Illinois and Indiana, and the shooters that Matteson calls "vandals" are mainly found in Illinois. The penalty for intentional shooting ranges up to $5,000.
Still, the project, which was funded mainly by private donations, is succeeding, says Matteson. The birds have established what he calls "a migratory tradition," and their health indicates that their marshes are in good condition. "Trumpeters are a symbol of nature's majesty, and a wonderful vehicle for promoting wetland conservation in the state," says Matteson. "They're ambassadors."
How do you train captive animals that are born to be wild?
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