By nesting in colonies, usually in bare trees above marshy areas, herons gain
 protection from predators. Photo by Forest Preserve District of DuPage County.

Rookery rebound

(published 7-1-22)

When leading a bird walk, I’m secretly grateful whenever a great blue heron comes into view. Lurking on the edge of a pond, or rowing across the sky, a “GBH” always makes an impression. It’s a big, majestic bird that everyone in the group gets to experience—a welcome respite from the challenge of spotting little birds in leafy trees.

For kids, especially, bigger is better. As a boy, I loved when great blues glided low over our suburban Ohio neighborhood, preparing to land on the nearby golf course. They looked huge and prehistoric. I’d shout out “Crane!” to anybody listening.

 Yeah, not proud of that, but I was 10. Butterflies and moths occupied my time in those days. 

Fortunately, my curiosity about birds (and their correct names) took off later in life and continues today. This led me to a drop-in program called Heron Rookery Rendezvous—a “pop up” viewing opportunity in late March offered by the Forest Preserve District of DuPage County. 

A great blue heron nesting colony—called a rookery or heronry—is located just west of the District’s headquarters building in Wheaton, in the Danada Forest Preserve. You can easily see it from the turf racetrack where 1965 Kentucky Derby winner Lucky Debonair once trained. 

Spotting scopes were set up, but even without them, the view was excellent. We counted 20 stick nests high in the bare cottonwood trees, some still under construction. 

The breeding season had just begun, with courtship behavior and mating on full display. A few herons were settled down on nests but were probably not incubating eggs just yet. 

Great Blue Herons prefer solitude when they feed, which can
 take place miles from the rookery. Photo by Christian Goers.

As the District naturalists shared their knowledge, I quickly realized how little I really knew about our largest commonly seen bird. My scribbled nuggets piled up fast: 

• Great blue herons usually feed alone, and they do so up to six miles away from the bustling rookery. Feeding is their “me time.”

• Like owls, the herons regurgitate pellets of indigestible materials, such as fish and frog bones.

• Herons possess special equipment just for preening—a “comb toe” on each foot and three patches of powder-down feathers.

• Nesting in large, noisy groups is for safety. Crows, great-horned owls, red-tailed hawks, and raccoons are common predators.

• The great blue is among 65 heron species worldwide, and one of six found regularly in northern Illinois.

My learnings included a new appreciation for the transitory nature of rookeries. They come and go. The one at Danada peaked in 2008 with 200 nests. By 2017, there were none. 

High winds can destroy a heronry. The nests are vulnerable, and so are the trees that hold them. Great blue herons prefer dead or dying trees in marshy areas. The leafless trees, already in decline, are further weakened by the acidic guano raining down from above.  

Land development and human disturbance are the greatest threats. You might recall the dust-up in 2014 when the Chicago Symphony Orchestra considered buying a 58-acre site near the Danada heronry to build a summer concert venue, an idea widely opposed by conservationists. 

The CSO plan never materialized, and yet the great blue herons still moved away. Now they are back, continuing a rebuild that began with a modest five nests in 2018, according to Forest Preserve ecologist Brian Kraskiewicz.  

The ebb and flow of the Danada heronry is a curious thing—an inspiring story of avian resilience in plain view. 

Back home in Indiana

I suppose curiosity also played a part in my return to the Indiana Dunes Birding Festival in May. What would it feel like, I wondered, after three years away? The pandemic wiped out the 2020 festival, and the 2021 edition employed a hybrid format. This year was back to normal, and normal at this event is very, very good. 

And it was—excellent birding and camaraderie in ideal weather. I especially enjoyed Trail 2 inside Indiana Dunes State Park, with its newly opened boardwalk. That hike alone was worth the 75-mile drive to Chesterton. 

The Indiana Dunes Birding Festival, hosted by Indiana Audubon,
succeeds by making birders of all ability levels feel welcome.

The festival’s bird list over five days totaled 207 species. Best of all were the colorful warblers, tanagers, and other spring migrants that light up the dunes every year. Keynote speaker David Lindo, “The Urban Birder,” rocked the Saturday night gathering. 

Kudos to Indiana Audubon for staging another winner. This was the festival’s eighth year and the biggest one yet with 650 registered birders. I can say with confidence that everybody who wished to see a cerulean warbler saw at least one and a whole lot more.

Copyright 2022 by Jeff Reiter. All rights reserved.