Brookfield Zoo's Trumpeter Swans

In March 2006, two zookeepers from Brookfield Zoo took a trip to Clinton, Iowa, to assist in releasing one of the zoo’s trumpeter swans to the wild as part of the state’s Trumpeter Swan Restoration Program. The bird hatched at the zoo in June 2005 and has spent the winter months at a holding facility managed by Iowa’s Department of Natural Resources (DNR). The swan from Brookfield Zoo along with one from Lincoln Park Zoo was released at Gomer’s Slough, a backwater wetland along the Upper Mississippi River National Wildlife and Fish Refuge.

On Wednesday, June 14, the Chicago Sun-Times reported that the first pair of nesting trumpeter swans in Illinois in more than 150 years was successful. Steve Bailey, ornithologist for the Illinois Natural History Survey, reported the Carroll County pair had at least one young hatched by last week. The nesters come from the reintroduced swans in Iowa, which Brookfield Zoo assisted.

Brookfield Zoo has been a long-time partner and leader in swan breeding and reintroduction programs with neighboring states. As a participant in Minnesota’s Department of Natural Resources Trumpeter Swan Restoration Project, the zoo had provided 10 eggs and 28 cygnets between 1984 and 1992. The zoo has been a participant in Iowa’s swan restoration since 2001 and has released four birds as part of that program. A cygnet that hatched at the zoo in 2004 and was released in Iowa last spring has been sighted numerous times with another bird also released last spring along the Mississippi River in and near Clinton.

The parent swans at Brookfield Zoo were introduced to each other last April. The male swan was brought to Brookfield after the female lost her previous mate the year before. He is from Kellogg Bird Sanctuary, a rehabilitation center in Michigan. His left wing is slightly curled with feathers sticking out at an unusual angle caused by a fused fracture he sustained prior to coming to the zoo. The injury prevents him from flying, which would be critical for his survival in the wild.

Trumpeter swans are the largest North American waterfowl, weighting up to 30-35 pounds with up to an 8-foot wingspan. The distinctive trumpet-like call that gives them their name at one time resonated throughout the upper Midwest and central Canada.

The recovery of wild swan populations throughout North America is one of the outstanding conservation success stories of the 20th century. Trumpeter swans were driven to the brink of extinction in the early 1900s due to a combination of indiscriminate hunting and loss of breeding habitat as the human population expanded. As recently as 1932, there were fewer than 70 swans in the lower 48 states.

Through coordinated captive breeding and reintroduction programs overseen by the U.S. Fish and Wildlife Service and managed at the state level, wild swan populations in the region have now grown to an estimated 4,000.