Constructed Wetlands Help Trumpeter Swans Thrive in Iowa

By Andi Anderson

A recent research project in Iowa shows that constructed wetlands designed to improve water quality also play an important role in supporting wildlife, especially Trumpeter swans. Graduate student Jayden Jech, who studies wildlife ecology, spent last summer leading detailed observations at more than 80 privately owned constructed wetlands across Iowa.

The main goal of these wetlands is to reduce nutrient runoff and improve water quality. However, Jech and his research team also wanted to understand how these wetlands contribute to wildlife conservation. With support from the Iowa Department of Agriculture and Land Stewardship and the Thamodaran Family Innovation in Agriculture Student Award, the team monitored wetland features and swan nesting activity from April through September 2025.

Using drones, the researchers measured wetland size, vegetation types, and other features such as muskrat huts that encourage swans to nest. Once a nest was found, the team visited regularly to track the survival of cygnets, or baby swans. Over the summer, more than 20 swan families were monitored. Out of 113 cygnets hatched, 106 survived through late August, showing a 93 percent survival rate.

“Seeing high survival was an exciting way to kick off the start of this multi-year project,” Jech said.

This success is especially meaningful because Trumpeter swans disappeared from Iowa in the late 1800s and did not return until the 1990s. Their growing presence reflects long-term conservation efforts by the Iowa Department of Natural Resources and its partners. According to Jech, constructed wetlands built for water quality improvement now appear to be helping the swan population expand.

“Jayden set an ambitious goal to see if he could visit nearly every constructed water quality wetland built in Iowa over the last two decades,” said Adam Janke, associate professor and Jech’s advisor. “He worked hard to connect with all these farmers and landowners, and it paid off with some fascinating insights into how wildlife, water and people can all benefit from agricultural conservation practices like wetlands.”

As warmer weather returns, Jech and his team are preparing to continue the project. They plan to use their findings to recommend better wetland design and management practices that support clean water, wildlife, farmers, and rural communities.

“Through this experience, I’ve gained an appreciation for finding innovative ways to address challenges of enhancing constructed wetlands to improve Iowa’s water quality, while also supporting wildlife and benefitting farmers and rural communities,” Jech said.

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