Black-crowned Night Heron - Photo Mick Thompson

Researchers from The Ohio State University and the Ohio Division of Wildlife have helped solve the mystery of where Ohio’s Black-crowned Night Herons migrate to in the winter.

The Ohio researchers teamed up with scientists at the Smithsonian National Zoo and Conservation Biology Institute in Washington, D.C. to track night herons that breed at the Zoo and along Lake Erie in Ohio.

Scientists attached transmitters to 28 night herons at their breeding grounds to see where they migrated for the winter.

One purpose was to see if where the birds wintered may play a role in why the Ohio population is declining, while the D.C. Zoo population is stable.

The researchers found that all the birds from the Ohio colonies migrated in winter, while some birds from the Zoo migrated shorter distances, some longer distances and others didn’t even migrate. The birds that did migrate from the Zoo shared similar wintering areas as the birds from Ohio, including Florida, Cuba, Honduras and Nicaragua. Some birds stayed in one place throughout the entire winter, while others moved around to different areas.

Most birds that were tracked for more than one year returned year after year to where they spent the summer, no matter where they spent the winter. This means that where the birds spend the winter may not be the reason the Ohio Black-crowned Night Heron colonies are declining. However, birds from these two distant areas mainly used only three locations to overwinter. Therefore, these areas may be important for conservation of the eastern North American population of Black-crowned Night Herons.

This project was done in collaboration with Chris Tonra and Kristie Stein from The Ohio State University; and Laura Kearns from the Ohio Division of Wildlife.