CORNING – Lake Icaria north of Corning will be the new home for six trumpeter swans released Thurdsay as part of a cooperative statewide restoration program with the Iowa Department of Natural Resources, county conservation boards and zoos nationwide.
The swans that were released are juveniles, called signets, born last spring in zoos across the country. Released yesterday were four swans from the Kansas City Zoo, one from the zoo in Oklahoma City and one from a zoo in Maryland.
Tiffany Mayo, trumpeter swan species survival plan coordinator and lead hospital keeper, at the Cleveland Metroparks Zoo said “There’s only a couple of states that have active restoration and Iowa is one of them, so what zoos do is support whatever restoration program that is active. With Iowa’s being active, we have four zoos that sent signets here today.”
She added that the swans are raised at the zoo, and then in the fall prior to their release they are sent to Iowa for what is called a soft release where they can acclimate to a more wild environment before being released at their future homes in May.
“So far, we’ve released about 1,200 of these young signets into the wild and we’ve got 54 nests in the state,” said Dave Hoffman, a wildlife research technician with the Iowa DNR. “We only have two pair that are in the southern half, so that’s our goal, to eventually have a self-sustaining population where they can make it on their own.”
The plan to restore trumpeter swans to the area began in 1994 with the first release in 1995. The first nest was established in 1998. Prior to that first nest, swans had been absent from the Iowa landscape since 1883.
During a presentation he made to a large gathering of children from area schools, Hoffman explained that the reason swans disappeared was because early settlers hunted them for food and their feathers.
“The people of Iowa really are the ones that initiated it [the plan],” said Hoffman. “They said they’d like to have trumpeter swans back because it’s part of our heritage and it promotes our wetlands and water quality and improves our quality of life. A grandmother said, ‘I’m worried about my kids and grandkids moving to another state.’”
When the birds come to Iowa for release, they have never flown before. While they were living at the zoos and in the soft release area, their wings were clipped to prevent them from flying.
“They’ve grown up in the zoo where they’ve kept their wings clipped,” said Travis Paul, conservation director on the Adams County Conservation Board, “so these birds have never flown. They will go through a molt and regrow feathers, and they will fly for the first time here at the lake. They typically imprint on the area where they learn to fly. What they will know as home is the area where they learn to fly. The idea is that these birds will join in with wild trumpeters that are migrating south for the winter, and then when they come back north in the spring, this area – so southern Iowa – will be their stop.”
There is a 75 percent mortality rate for the young signets released in the wild. Mortality factors for swans include lead poisoning, powerlines, disease and getting shot.
Swans mate for life and both parents will typically share the duties of caring for the young. Bonded pairs do not typically begin forming until swans reach 5 to 6 years of age, which is one reason there are only 54 nesting pairs in the state.
Few swans in the wild will reach sexual maturity, age 6 for females and age 3 for males, so establishing a sustainable population is simply a matter of releasing enough swans so that the number that survives begins to outweigh the number lost.
“In the wild, if we can average 7 or 8 years, it’s going to be good,” said Hoffman.
Trumpeter swans are large birds. Their wing span stretches out more than 6 feet and they can weigh anywhere between 20 and 30 pounds. Because the swans released at Lake Icaria are still juveniles, their feathers are still grey, but once they go through their summer molt, they will be pure white.