Trumpeter swan taking flight. (Photo by Karl Heil/USFWS)

Once pushed to the brink of extinction by hunters selling their skin, feathers, meat and eggs, trumpeter swans have made an incredible comeback, thanks to an international treaty and wetlands restoration efforts.

Iowa is now at the forefront of research to better understand the habits of this protected species.

Related: Iowans charged with shooting trumpeter swans

Learn more about those research efforts in this information provided by the U.S. Fish and Wildlife Service:

Trumpeter swans have been making an incredible recovery across Canada and the United States since restoration efforts began in the 1930s, with more than 46,000 estimated to live across North America today. While biologists know a great deal about them, there’s so much left to learn about their preferences for breeding sites, migratory movements and overwintering. Biologists at Union Slough National Wildlife Refuge in Iowa are working together with colleagues from Iowa State University and the Iowa Department of Natural Resources to find out.

Thanks to the generous support of the Friends of Union Slough, the research team was able to double their efforts. In addition to Friends-funded GPS collar that the team placed on a swan captured at the refuge, Iowa State University funding covered the cost a second collar for a young swan that the team captured on Maynard Reece Waterfowl Production Area. The collars are expected to provide valuable information for approximately three years. During this time, we will be able to help Iowa State University and Iowa Department of Natural Resources biologists evaluate trumpeter swan breeding locations, migratory movements and wintering areas.

Trumpeter swan protection and recovery has a long history in North America, that dates back to the Migratory Bird Treaty Act of 1918. This international treaty between the United States and Canada stemmed from the extreme degradation of trumpeter swans and other migratory bird populations that started in the 1800s. By the early 1900s, trumpeter swans were pushed to the brink of extinction by market hunters for their skin, feathers, meat, and eggs.

National wildlife refuges have been outdoor classrooms and living laboratories since the first refuge was established in 1903. Wildlife biologists, forest ecologists and ornithologists have partnered with federal land managers and biologists to better understand and protect America’s natural resources. Union Slough National Wildlife Refuge has been a part of this tradition since it was established in 1938, with a focus on migratory waterfowl and providing unting opportunities for upland game like pheasant, gray partridge, and cottontail rabbit.

Even though the refuge welcomed 10 trumpeter swans back in 1996, as part of Iowa’s reintroduction effort, this is the first time they have directly participated in a swan research project. Information collected will be used by The Trumpeter Swan Society and all coordination for the project was with Dr. Stephen Dinsmore at Iowa State University. The data collected will also be analyzed by the ornithology class at the university in the spring of 2018, which complements the educational aspect of this project. Information will further educate the public about trumpeter swan ecology and movements through a website that provides regular updates on marked swan locations.

Healthy habitats make for healthy swans

Quality habitat has always been available at Union Slough National Wildlife Refuge and in the almost eight decades since it was established by Franklin Delano Roosevelt, the refuge has been a welcome stopover for migrating waterfowl. Once the trumpeter swan reintroduction program started, it was just a matter of time before there were successful nesting pairs at the refuge.

In 1994, Iowa Department of Natural Resources began releasing trumpeter swans in Iowa. The goal was to establish 15 wild nesting pairs by 2003. That goal was later revised to have 25 wild nesting pairs, which was achieved in 2005. The current goal is to have a self-sustaining population in the state of Iowa. Iowa Department of Natural Resources biologists, and other researchers like Dr. Dinsmore, are working to determine how many nesting pairs are needed for a self-sustaining population. The refuge currently has the highest concentration of nesting swans in the state and in the past year had six nest sites out of the 55 known trumpeter swan nest attempts in Iowa. That’s 11% of all nesting pairs in the state!

“We recently restored several acres on Maynard Reece Waterfowl Production Area and some other waterfowl production areas close to the refuge. Any time we can restore a semi-permanent wetland in the northern part of the District, there’s a high probability of nesting trumpeter swans there,” said Project Leader Edward Meendering.

Since 2003, the refuge and the nearby waterfowl production areas have successfully hatched 305 cygnets. Having quality habitat on the refuge and restoring as many wetlands as possible within Iowa Wetland Management District has definitely supported the trumpeter swan reintroduction program. This ongoing work also benefits upland game hunting opportunities, a wide community of pollinators, and helps to improve local water quality.

The slough that makes up part of the refuge landscape is all that remains of a pre-glacial riverbed and the name “Union” refers to the connection of two watersheds, the Blue Earth River and the east fork of the Des Moines River. Native Americans called this area Mini Akapan Kaduza, meaning “water which runs both ways.”

During the early settlement times, Union Slough covered 8,000 acres and was considered useless for farming. Many levees and ditches were built in this area in an attempt to control water levels and improve the area for agriculture. In spite of these habitat changes, the area continued to support an abundance of waterfowl, as well as wetland and upland wildlife species. Refuge uplands surrounding Union Slough still contain remnant tallgrass prairie, a rare commodity in an intensively cultivated area. Today, Union Slough National Wildlife Refuge encompasses 3,334 acres of both marsh and upland habitat.

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