It was a cold, quiet Saturday in February, when a couple dozen people gathered by the open water behind McHenry Dam on the Fox River.
They huddled together, bundled up in the parking lot. A few stooped behind spotting scopes, which are essentially long-range telescopes set up on a tripod. A few were trained on a huge nest up in a tree on the other side of the river.
They were looking out for bald eagles.
This gathering was part of an eagle-watching series the Illinois Department of Natural Resources, McHenry County Audubon and other conservation groups host. The eagles are easier to see in the winter before the trees leaf out.
The bald eagle used to be a rare sight in Illinois. Now, there are more than 3,000 that spend the winter here. Illinois is home to the largest wintering population of eagles in the continental U.S. according to the IDNR. It's considered a conservation success story.
At one point in the course of the morning, the pair of eagles returned to their nesting site. They perched together on a tree across the dam, just far enough away to appear as two brown dots on a branch.
The scopes the IDNR and McHenry Audubon set up for this event are much more powerful than binoculars alone. Bird enthusiast Susanne Petersson liked being able to see the birds with much more clarity.
“We get to see eagles up close and personal, because we don't have this type of equipment,” Petersson said. “We would see a spot in the sky. So this is really terrific.”
There have been eagle watching events throughout the state in January and February. But, because the nest is so visible from this vantage point, IDNR’s natural resource coordinator Stacy Iwanicki said visitors can see them pretty easily here.
“They'll come to where they can find the open water, which when the river freezes, generally, is just on this on the downstream side of dams,” Iwanicki said. “Which is what makes McHenry Dam such a great location.”
Seeing these creatures would have been nearly impossible a few decades ago.
Bald eagle populations were almost nonexistent in Illinois in the 1970, mainly because of the widespread use of DDT, a pesticide that built up in the fish that eagles ate. The pesticide disrupted their endocrine system, thinned their eggshells and ultimately decimated the reproduction of eagles. DDT was banned in 1972. Soon after, IDNR and the Audubon Society started protecting habitat for the birds. In the late 70’s, there was just one nest found in Illinois. Now, bald eagle nests are found in most counties in the state.
A recovery like this one demonstrates the potential for humans to change course and take action, Iwanicki said.
“It was also a success story,” she said. “It was humans realizing there was a problem, understanding what that problem was, and knowing there was a solution, and coming together and agreeing to make the solution happen.”
It was a good day for birders at McHenry Dam; Iwanicki pointed out some ducks splashing around in the open water.
"I am looking at common golden eyes and redheads,” she noted. “There's two redheads. They're kind of self-explanatory; their heads are very red.”
And the eagles usually like to stir up the Canada geese as well.
“Seldom do they ever catch one of the geese, but it gets their attention, and the whole raft of geese will just float up all at once. It has not happened yet today, but it's impressive when it does.”
Events like this are special because they get people outside and away from their screens, said Jim Bolm, who’s on the board of directors at the Friends of Moraine Hills State Park.
“(It’s meaningful) to the people to be able to come to a place where you have some quiet,” Bolm said. “You can see other animals—whether it's the birds or beavers, turtles, snakes, all these things—and to be able to see that instead of being constantly in an artificial world.”
Susanne Petersson has been coming to the eagle watching event for the past few years, and she was excited to witness a nesting pair.
“It's just the grandiosity of nature, she said. “They're just so beautiful. And I mean, I get excited over the geese too.”
The event is simple — visitors just have to show up, observe and maybe meet another bald eagle enthusiast. But there’s something deeper, Iwanicki said.
“Nature's a great equalizer,” she said. “We can all come together, regardless of what the rest of our life looks like, and just enjoy nature. Bald eagles are a gateway to understanding nature in a broader scale.”
Nesting season is currently underway. Pairs will take turns incubating their eggs, which usually hatch in March and April. That means eaglets may be visible at the dam in the coming months.
