The nearly two dozen trumpeter swans residing here on the Cedar River below the roller dam in Cedar Rapids attest to the success of the state’s swan reintroduction program.
“For all the effort that has gone into the program, a large flock in an urban area is a nice indication that it is paying off,” said Ken Carroll, a parks and natural resources assistant professor at Kirkwood Community College – an institution that has been deeply involved in the restoration effort since shortly after field work began in 1995.
Department of Natural Resources wildlife biologist Dave Hoffman, who coordinates the program, said he is not greatly surprised to learn of the swans’ concentration in the state’s second-largest city.
“The swan population is growing. They are attracted to open water, which is becoming hard to find right now. And the area has nearby crop fields where they can feed,” Hoffman said.
The swans have been on the Cedar since at least Monday, and Kirkwood students and staff have been regularly monitoring them since Tuesday.
Carroll said the birds’ presence on the river has prompted expressions of concern about their safety, following the wanton fatal shooting in February of a swan residing on a pond on the Kirkwood campus.
That incident remains under investigation, and a $1,000 reward remains in effect for information leading to the arrest and conviction of the responsible party, according to Dick Heft, board chairman of Turn In Poachers of Iowa.
Heft said pertinent information should be referred to local law enforcement authorities and can be provided anonymously by calling the TIP hotline, 1-(800) 532-2020.
Hoffman said shooting is the leading cause of mortality among swans and “one of our most frustrating challenges” in restoring the majestic birds to their native Iowa.
“We had three or four shooting deaths last year and 57 since the program began,” he said.
Some of the shootings have been classified as “mistaken identity” on the part of hunters, but others, including the Kirkwood slaying in February, have been classified as “thrill kills,” in which the shooter knowingly kills a legally protected bird.
Other leading causes of swan deaths, Hoffman said, are power line collisions, lead poisoning, predators, disease and, last year especially, the ill effects of drought, which dislocated many young swans when their natal wetlands dried up.
Despite more than 250 known swan deaths since the mid-1990s, Iowa’s swan population has grown steadily and is close to establishing a sustainable wild population, according to Hoffman.
The state now has about 50 wild nesting pairs raising about 80 cygnets to flight stage each year. Successful nests have occurred in at least 20 of Iowa’s 99 counties, mostly in north-central and east-central Iowa. Tagged Iowa swans have been observed in 17 states and two Canadian provinces.
Carroll said one of the swans on the Cedar River has a yellow neck band inscribed with “27T.”
“That’s a Wisconsin band, and the swans on the river are probably a mixture of Iowa and Wisconsin swans,” said Hoffman, who encourages Iowans to report nesting or marked swans by calling (641)-357-3517.
Following recent cold weather, Iowa has received an influx of waterfowl and other birds from Minnesota and Wisconsin, he said.
Before the reintroduction, the last nesting pair of trumpeters in the Iowa wilds was seen in 1893 in Hancock County in north-central Iowa. The birds became extinct in Iowa because of the drainage of wetlands for farm production and because the big birds were shot for food and feathers before the turn of the century.
Trumpeter swans, the only swans native to Iowa, are North America’s largest waterfowl, weighing up to 30 pounds at maturity and with a wing span of 7 feet. They are distinguished by their loud trumpet sound.