New residents to the area are sparking a triumphant comeback story. Perhaps it is a sign of a thriving waterway full of aquatic prey, but a resurgence for a species of birds is making its presence known. Once considered endangered in Illinois, ospreys are returning to Illinois and making a visit to local waterways and even made a visit to the Stickney Water Reclamation Plant.

Senior Environmental Research Technician Paula Brinkman-Lowe from the Metropolitan Water Reclamation District of Greater Chicago (MWRD) Aquatic Ecology section said she has observed a growing number of ospreys nesting since 2017.

“I am lucky enough to be able to spend a fair amount of time on the rivers on our boats. Over the last four years, I have noticed a growing number of osprey nests - from one at our SEPA (Sidestream Elevated Pool Aeration) Station to four last summer, two on the Chicago Ship and Sanitary Canal and two on the Cal-Sag Channel,” said Brinkman-Lowe. “Ospreys have been endangered in Illinois, so this is wonderful news!”

Decades ago, an osprey would be a rare sight. Experts say the osprey population began dwindling in the early 1950s due to the rampant use of DDT in pesticides. The U.S. banned certain pesticides in 1972, during the same year as the federal Clean Water Act, and ospreys have been making a comeback ever since. In 2020, the Illinois Department of Natural Resources listed the osprey (Pandion haliaetus) as threatened.

Described by the Audubon Society as a “fish-hawk,” the ospreys are formerly classified as a hawk. The osprey lives near rivers, lakes, reservoirs and coasts and migrate south during the winter in the southern United States and as far as South America. With a majestic six-foot wingspan, they fly over the water, hover, and then plunge feet-first to catch fish in its talons. They also share a resemblance to eagles without the eagle’s full white head or tail. Ospreys have a broad brown band through the eye, a brown back and white belly, according to the Chicago Botanical Garden, which helped install an osprey nesting site in 2016 near the Skokie Lagoons in Glencoe with the Cook County Forest Preserve District and Friends of the Chicago River.

It also benefits the ospreys to have access to fish thriving in a clean water supply protected by the MWRD.

“We have known for some time that the Chicago-area waterways provide better-quality habitat for fish and aquatic life than they did a half-century ago,” said MWRD Commissioner Debra Shore. “All the components of an ecosystem are interlinked, so that when you improve conditions in one part, you will see effects up and down the ecological chain. The reemergence of ospreys is a sign that we are doing something right.”

From 10 known species in 1974, that number has ballooned to 77 by 2019, including 60 that have been found in the CAWS since 2000. A study unveiled in 2020 by the MWRD and Shedd Aquarium demonstrated that there has been a gradual increase in both the total number of fish and fish species in the CAWS. The number of invasive species also declined.

In 2020, the MWRD also documented how dam removals have increased fish migration. A largemouth bass caught by a fisherman in the Skokie River had been caught and tagged by MWRD aquatic biologists seven months earlier for research in the North Branch Canal by Goose Island.

“This rare find would never have been possible if not for a partnership effort to remove a century-old dam on the North Branch of the Chicago River as part of a restoration effort by the U.S. Army Corps of Engineers-Chicago District, Chicago Park District and MWRD,”
said Commissioner Mariyana Spyropoulos.

Osprey return_PR_R.pdf