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Black Tern Monitoring at St. Clair Flats

Black Tern in flight. Photo by David Fuller.

The largest Black Tern breeding colony in Michigan resides in St. Clair Flats. Studies have shown that many smaller breeding colonies are disappearing, making the St. Clair Flats colony especially valuable. Black Terns spend half their life flying over the ocean off the coast of Central and South America, and half breeding in U.S. and Canadian Marshes. The birds create their nests on mats of vegetation floating in the water. Despite their charm and unique lifestyle, the birds are not well understood and their populations are decreasing.

Volunteers counting Black Terns. Photo by Ava Landgraf.

Adult Black Tern feeding a juvenile. Photo by Diana Whiting/Audubon Photography Awards 2015.

Black Tern nest. Photo by Ava Landgraf.

We must act now!

If population numbers continue to drop, it will become increasingly difficult to restore the populations to sustainable numbers. Due to the urgent need for action, the Black Tern is receiving increasing attention from federal and state agencies. Only with continued research can we determine the causes of Black Tern population decline in Michigan and across North America.

Volunteer Rachel Gumpper releasing a banded Black Tern. Photo by Ava Landgraf.

Black Tern chick being weighed. Photo by Ava Landgraf.

Juvenile Black Tern with nanotag. Photo by Alex Jahn.

How is Detroit Audubon supporting Black Tern conservation?

Detroit Audubon has partnered with Audubon Great Lakes and National Audubon to monitor the St. Clair Flats Black Tern colony since 2013. Detroit Audubon Research Coordinator, Ava Landgraf, monitors and bands the Black Terns on St. Clair Flats for two days every week, between May 15th and August 10th.  Early in the season, Ava surveys St Clair Flats recording sub-colony and nest locations. As the season progresses, monitoring goals shift to capturing and banding adult Black Terns. Through this work, we can obtain a better understanding of Black Tern population dynamics–number of chicks successfully leaving the nest and the number of adults which return year-to-year. Understanding Black Tern population dynamics at St. Clair Flats will allow us to see when issues are occurring (during nesting, post-nesting, migrating etc.) and enable us to develop and implement a plan to address those issues.

In 2019, high water levels, frequent storms and limited vegetation mats seemed to decrease the nesting success of the Black Terns. Unfortunately, these variables are not likely to decrease. For 2020, Detroit Audubon will test the use of floating, man-made nesting platforms.

Past Research Coordinator, Erin Rowan banding a chick. Photo by Diane Cheklich.

Two Black Tern chicks. Photo by Ava Landgraf.

Partners, Dave Fuller and Jenni Fuller, installing a nest camera. Photo by Ava Landgraf.

Banding adult Black Tern. Photo by Diane Cheklich.

Get Involved!

If you are interested in supporting Detroit Audubon’s Black Tern monitoring, please contact our Research Coordinator, Ava Landgraf, at alandgraf@detroitaudubon.org.


Partner Jenni Fuller and volunteer Guadalupe Cummins counting Black Terns at St Clair Flats. Photo by Ava Landgraf.